U.S. patent application number 16/570223 was filed with the patent office on 2020-01-02 for multi-user cloud parametric feature-based 3d cad system with reference manager.
The applicant listed for this patent is OnShape Inc.. Invention is credited to Scott S. Harris, Malay Kumar, Karl Evan Nowak, Parapura Rajkumar.
Application Number | 20200004898 16/570223 |
Document ID | / |
Family ID | 56693752 |
Filed Date | 2020-01-02 |
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United States Patent
Application |
20200004898 |
Kind Code |
A1 |
Harris; Scott S. ; et
al. |
January 2, 2020 |
Multi-User Cloud Parametric Feature-Based 3D CAD System with
Reference Manager
Abstract
Disclosed is a parametric feature-based 3D CAD system that
allows multiple users to simultaneously edit a parametric
feature-based 3D CAD model consisting of 3D parts and assemblies of
those parts (3D Model). Several CAD users, each using their own
computer, phone, or tablet, can edit the same 3D Model at the same
time. Editing may be separate and simultaneous--there is no need
for users to worry about locking, checking out, or otherwise
restricting each other's access to 3D Models. As a result, users
see each other's changes occur in real-time, and may also identify
what aspects other users are actively modifying through visible
Collaboration Cues.
Inventors: |
Harris; Scott S.; (Acton,
MA) ; Nowak; Karl Evan; (Saint Paul, MN) ;
Rajkumar; Parapura; (Acton, MA) ; Kumar; Malay;
(Acton, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
OnShape Inc. |
Cambridge |
MA |
US |
|
|
Family ID: |
56693752 |
Appl. No.: |
16/570223 |
Filed: |
September 13, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15052418 |
Feb 24, 2016 |
10437938 |
|
|
16570223 |
|
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62120672 |
Feb 25, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 30/17 20200101;
G06F 2111/02 20200101; G06F 30/00 20200101; G06F 2111/04
20200101 |
International
Class: |
G06F 17/50 20060101
G06F017/50 |
Claims
1. A system for executing three dimensional (3D) multi-user
distributed parametric computer-aided design (CAD), the system
comprising: one or more servers; one or more client devices
connected over a network to the one or more servers; server
software executed on one or more servers, the server software
comprising code to: perform CAD geometry calculations including
shape analysis and optimization of 3D graphics data, manage CAD
editing workflow, manage user accounts and secure access,
communicate with the one or more client devices, manage documents
and storage by storing multiple files grouped together as a single
data structure, the multiple files comprising data representations
of assemblies, parts, and non-CAD data of a project encompassing
the 3D CAD design, and incorporate references to one or more parts
or sub-assemblies used in the project where the references
originate from one or more separate projects; client software
executed on the one or more client devices, the client software
comprising code to render a user interface for displaying 3D CAD
graphics for design and project management, interact with user
input and output controls to manipulate a 3D CAD design, and
communicate with the one or more servers; wherein the 3D CAD design
includes one or more parts and one or more assemblies consisting of
connections and configurations of the one or more parts and
sub-assemblies, and the client software further comprises code to
enable a user to manipulate the parts and assemblies of the 3D CAD
design through ordered feature lists.
2. The system of claim 1, wherein the server software further
comprises code to create and store a copy of each reference
originating from the one or more separate projects, store each copy
with the project, and store references between geometry of the copy
and the originating reference.
3. The system of claim 2, wherein the server software further
comprises code to examine all references when the geometry of the
originating reference is changed and provide notification to any of
the client devices which are accessing the 3D CAD design after the
originating reference is changed, and the client software further
comprises code to display alert messages to users after receiving
such notification.
4. The system of claim 3, wherein the client software further
comprises code to display options and receive input from a user
selecting to synchronize with the originating reference, edit
geometry applicable to the changed reference, or dismiss changes
and use the copy instead of the geometry of the changed originating
reference.
5. The system of claim 4, wherein the client software further
comprises code to display additional options and receive input from
a user selecting to synchronize all references, synchronize
selected references, or dismiss all references when multiple
originating references have changed.
6. The system of claim 5, wherein the server software further
comprises code to regenerate the 3D CAD design using the geometry
of the changed originating reference after a user selects to
synchronize.
7. The system of claim 1, wherein the one or more servers include:
one or more 3D geometry calculation servers (3DGCS) with server
software including code to solve 3D constraints and perform
geometry calculations modifying representations of geometric
shapes; one or more data persistence servers (DPS) with server
software to store user account information and data associated with
the 3D CAD design; one or more CAD editing workflow servers (CEWS)
with server software including code to receive user account,
project interaction, and geometry modification messages from the
one or more client devices, read and write CAD data from the one or
more data persistence servers, and coordinate message exchange
between the one or more client devices and the one or more 3DGCS;
one or more two dimensional drawing editing workflow servers
(2DDEWS) with server software including code to create and
manipulate two dimensional (2D) drawings; one or more data cache
persistence servers (DCPS) with server software including code to
store and retrieve frequently accessed CAD model information; one
or more document management web servers (DMWS) with server software
including code to communicate with the one or more client devices
and provide information about CAD designs accessible by users of
the one or more client devices; and one or more distributed
configuration controller servers (DCCS) with server software
including code to communicate with and manage other servers and
direct communications between the one or more client devices and
appropriate specific CEWS based on any currently open 3D CAD
designs, CEWS server load, CEWS performance, or geographic
location.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This utility patent application is a continuation of and
claims priority from U.S. patent application Ser. No. 15/052,418,
filed Feb. 24, 2016, titled "Multi-User Cloud Parametric
Feature-Based 3D CAD System" naming inventors Jon K. Hirschtick,
Michael R. Lauer, Scott S. Harris, Paul R. Chastell, Ilya Baran,
Lana Saksonov, Ravi Nallapareddy, Nicholas J. Eyre, Karl Evan
Nowak, John Rousseau, Rammohan Vangapalli, Andrew John Morris,
Steven C. Hess, Philip Gareth Thomas, Daniel Vlasic, Louis V.
Gallo, III, Parapura Rajkumar, and Malay Kumar, which claims
priority from U.S. provisional patent application Ser. No.
62/120,672, filed Feb. 25, 2015, titled "Multi-User Cloud
Parametric Feature-Based 3D CAD System" naming inventors Jon K.
Hirschtick, Michael R. Lauer, Scott S. Harris, Paul R. Chastell,
Ilya Baran, Lana Saksonov, Ravi Nallapareddy, Nicholas J. Eyre,
Karl Evan Nowak, John Rousseau, Rammohan Vangapalli, Andrew John
Morris, Steven C. Hess, Philip Gareth Thomas, Daniel Vlasic, Louis
V. Gallo, III, Parapura Rajkumar, and Malay Kumar.
COPYRIGHT NOTICE
[0002] A portion of the disclosure of this patent document contains
material that is subject to copyright protection. The copyright
owner has no objection to the facsimile reproduction by anyone of
the patent document or the patent disclosure, as it appears in the
Patent and Trademark Office patent file or records, but otherwise
reserves all copyright rights whatsoever. Copyright 2016 Onshape
Inc.
BACKGROUND
Field of Technology
[0003] This disclosure relates to Computer Aided Design (CAD), and
more specifically to a multi-user three-dimensional online CAD
system.
Background
[0004] Computer aided design (CAD) is a type of software that
enables users to design real-world objects, such as machines and
other commercial products. Typical CAD users are designers or
engineers from businesses or individuals that want to precisely and
efficiently create product designs which represent physical
objects.
[0005] There is a long history of development behind CAD, as design
software allows features and functionality beyond the scope and
capability of draftsmen working on paper. CAD software can design
in two dimensions (2D CAD) or three dimensions (3D CAD). Since
1988, with launch of Pro/ENGINEER, parametric solid modeling has
emerged as a mainstream technology for design tools. The basic
capability of all parametric solid modeling systems is to allow
users to change dimensions (and other parameters such as directions
and definitions) of features being generated, allowing the models
to be changed. A parametric model in a CAD system is represented by
a data structure that in its most basic form is a linear set of
features (such as sketches, extrusions, fillets) that are executed
in order to create the model. These features define the eventual
shape of parts. This is usually called a "parametric history" or
"feature list" in products such as PTC's Creo, Dassault Systems'
Solidworks, and Autodesk's Inventor. The parametric history is
created through a user interface by directly applying features to
the 3D CAD parts.
[0006] Prior parametric feature-based 3D CAD systems are generally
designed for a single user to use at one time. If users work in
teams with other users, either copies of a CAD system must be
installed on each user's computer, or users need to use a separate
collaboration server that works independently of the master CAD
model. CAD data must be copied to each user's computer, or to and
from a collaboration server. Users must be ever-vigilant to be
certain they are not over-writing each other's changes and that
they are looking at the current latest version of a CAD model. CAD
software and separate collaboration servers need to perform complex
tasks to convey changes back and forth between the collaboration
servers and the master CAD model.
[0007] Existing parametric feature-based 3D CAD systems are
generally designed around the use of many files. Each CAD part,
assembly, and drawing are typically stored in individual data files
in a computer's file system. If users work in teams with other
users on a design, copies of all relevant files, CAD and otherwise,
are copied to each user's computer. If a new file is introduced,
for example for a new part, that file must be copied to all CAD
users who need it. If the design needs to be versioned to save a
specific state, then all of the many files need to be versioned.
External systems such as product data management (PDM) servers are
usually needed to perform version control and associate together
the many individual files comprising a product design.
[0008] Even with external solutions like PDM servers, collaborating
and synchronizing work is challenging. A team of designers may wish
to collaborate on designing a model, in such a way that each
designer works on one part of the model without interference from
his or her teammates. When one or all of the designers are finished
with their specific tasks, each of their work products must somehow
be incorporated into the finished model. Existing CAD systems
usually do not provide any real mechanism to do this. Either the
model must be subdivided in advance (e.g. as different parts in an
assembly), which is not always practical or possible, or each
designer's work has to be manually and laboriously re-created in
the final design.
[0009] Similarly, a designer or team of designers may wish to
experiment with a number of different design alternatives to each
of several different aspects of a design. The designer(s) may want
to mix and match alternatives of different pieces of the model, and
as above will need to merge the chosen alternatives together into a
final model. This is a challenging exercise under existing CAD
systems, which generally lack such enabling tools. It can sometimes
be possible to do simple merging of geometry, for example using
"boolean" operations, but that only combines the geometry and not
the parametric histories or feature lists.
[0010] In software development (as opposed to CAD model
development), visual comparison and merge tools such as Araxis
Merge and Perforce's p4merge are standard. These tools allow a
software developer to compare the textual representation of two
versions of the same software source code side by side on a line by
line basis (lines of code). The differences are highlighted in a
color coded manner (new lines, removed lines, modified lines are
each different colors). Since the format of the lines of code are
very familiar, the software developer can immediately understand
what has changed and can incrementally choose to transfer changes
from one version to the other. This is true whether the developer
is looking at code he or she wrote or code written by others. This
methodology is useful both to a software developer working alone
and to software developers working in teams. It is also standard
practice to use such tools in code reviews.
[0011] Some integrated development environments (IDE's) analyze the
program structure and display a graphical version of it. They may
allow basic editing operations through the graphical version. Some
CAD systems, such as SolidWorks, allow embedding programs into the
feature history. The entire program is represented as a single
feature and the structure of the program is not tied to the user
interface. OpenSCAD is a CAD system based on a programming
language, but it does not support viewing or editing the model via
a non-text-based UI. Thus, CAD development tools lack the
functionality and capability of software development tools when it
comes to visually comparing or merging development efforts.
[0012] CAD systems involve complex solvers to calculate models from
parameters and features configured by the user. Most CAD systems
include a sketcher, which is a portion of the software that can
allows users to create and manipulate curves and geometries in two
or three dimensions. Such sketchers include complex relationships
which are non-trivial to compute and typically use a commercially
available component or other complex library to evaluate. In
existing CAD applications that are resident on the user's computer
such calculations can be performed and results returned in near
real time. However, this requires sufficient processing power on
the local machine, and geometric data on the local machine to
compute geometries while sketching. As a result, multiple issues
exist when moving to a client-server model.
[0013] In addition, CAD systems often compute inferences about
relationships between various geometric entities to aid user design
while sketching. Traditional CAD inferencing performs calculations
on a local machine as a user moves the mouse on the screen. With
all calculations being on the local machine, any delays with mouse
movement can be kept short. However, even with a reasonable
powerful machine and local machine calculations, inferencing delays
with complex sketches or models may become noticeable.
[0014] In a client-server CAD architecture, there are multiple
approaches. A simple approach performs all inferencing on the
server, where the data and processing power reside. The latency of
connection from client to server means that the user receives
results much more slowly than in a traditional CAD application. A
second approach is to perform all the inferencing on the client.
This avoids the latency delays while inferencing, but requires a
lot of data transmission pre-inferencing (all the model data needs
to move from the server to the client), and requires substantial
calculation (processing power) at the client. With large and
complex models, this second approach does not scale
effectively.
[0015] When inferences are calculated, existing geometric entities
are often "snapped" to a calculated inference. SolidWorks, Creo,
AutoCAD, Fusion, SolidEdge are existing systems for 2D or 3D CAD
which perform snapping while inferencing during model sketching.
However, all of these products have implementation on a single
machine which does not scale effectively to a client-server system
with high latency.
[0016] Even without inferencing, any geometric movements made while
sketching can have latency and performance issues in a
server-client model. When dragging entities in a sketch, typically
the solver calculates new positions of geometry after every mouse
move. With sufficient processing power, these calculations can be
made efficiently so that even fairly big sketches can drag quickly.
However, in a client-server system when those calculations are on a
server, the latency of communication can greatly reduce the rate at
which responses are received. For example, with a travel time
between client and server of 125 ms each way it will take at least
250 ms plus calculation time to send the drag to the server and get
the response back. This results in user-perceived sluggish behavior
with the system (and model updates) lagging significantly behind
user control.
[0017] Beyond user control and complex geometric calculations, a
CAD model includes geometry of objects generated through a
parametric history and the relationship between them and other
objects generated by separate parametric histories. In a typical
CAD model with many parts and references, these relationships are
often confusing and difficult to manage. References between objects
are defined in a context, usually based on a position or logical
relationship in an assembly. An issue with every parametric solid
modeler is that changes made to one part of a model causes
unexpected behavior and failures in other parts of the model.
[0018] In the 1980's Pro/ENGINEER tried to minimize these failures
by forcing users to completely define all aspects of a design.
Every dimension or relationship was required to fully constrain all
geometric definitions before any feature or geometric element could
be created. This reduced many types of system failures, but was a
burden to the user. It was also very possible to build
unpredictable behavior despite the restrictions.
[0019] In 1995 SolidWorks introduced a parametric modeling system
that did not require fully constrained models. It relied on a high
quality variational solver from DCUBED and internal software to
product a reasonably reliable system. Though better after 20 years
of continued development, the system (as well as all other CAD
systems) still suffers from failures and unpredictable behavior in
may situations. Of particular concern are models where a change is
inconsistent with it's construction. For example, if a cut that is
referenced by another part is changed such that a referenced edge
disappears, the generation of the referencing part will fail.
[0020] U.S. Pat. No. 8,214,423 "CAD system" (Stefan Freitag, Jul.
3, 2012) discloses, in the Abstract, "A computer aided design (CAD)
system is described where each type of change in a CAD-generated
object is automatically and chronologically protocoled so that the
object directly includes an abstract description of the history of
the object independent of the CAD module used. This is particularly
advantageous with decentralized CAD systems in which several
constructors/designers are working together on the same draft, but
located in different places. At the end of a session, the object
history, i.e., the changes which have taken place, are directly
exported, together with the object data, into the destination
system. The abstract description is in a form independent of the
system used." This improves 3D CAD modeling to allow collaboration
across multiple CAD systems.
[0021] None of the above provides a CAD system enabling
three-dimensional, multi-user CAD with online access from any
platform or any device, online file storage and handling,
non-lagging server-side inferencing, client-side predictive
dragging, integrated branching and merging, multi-directional text,
feature, and graphical editing, and management of relationships to
avoid destructive changes from separate parametric histories. What
is needed, therefore, is a CAD system that overcomes the
above-mentioned limitations and that includes the features
enumerated above.
BRIEF SUMMARY
[0022] Disclosed are details of a parametric feature-based 3D CAD
system that allows multiple users to simultaneously edit a
parametric feature-based 3D CAD model consisting of 3D parts and
assemblies of those parts ("3D Model"). Several CAD users, each
using their own computer, phone, tablet, wearable computer (e.g.,
glasses, watch, etc.), or other connected computing device, can
edit the same 3D Model at the same time. Editing may be separate
and simultaneous--there is no need for users to worry about
locking, checking out, or otherwise restricting each other's access
to 3D Models. As a result, users see each other's changes occur in
real-time, and may also identify what aspects other users are
actively modifying through visible "Collaboration Cues."
[0023] The Multi-User Parametric Feature Based 3D CAD system is
constructed in several parts. Sets of computers ("Servers") perform
3D geometry calculations, manage CAD editing workflow, and manage
interactions between user client devices (computers, tablets,
phones, etc.) and the CAD editing servers. These sets of computers
may be distributed in multiple remote data centers (sometimes
referred to as "cloud" or Software-as-a-Service (SaaS)
infrastructures). Client software operates on user computer devices
to display a graphical interface for CAD editing. Client software
may be a dedicated program or application stored on the user
computer device, or loaded on demand such as within a web browser
with no user installation action required. A network and system of
communication passes asynchronous messages among these Servers and
the client software. 3D information flow is optimized for rapid
model and change dissemination. This solution implements multi-user
parametric feature-based 3D CAD without the need for a separate
collaboration server, and no need to copy data between a master CAD
model and a collaboration server.
[0024] Features and Advantages
[0025] This multi-user parametric feature-based 3D CAD solution
provides many benefits and advantages over prior CAD systems.
[0026] Users complete their work faster and more accurately since
there is no need to wait for other users to complete their work and
copy files to each other [0027] Users can work simultaneously on
the same 3D models and projects [0028] Because users do not have to
deal with copied files which easily become out of sync, data
management complexities requiring complex add-on functionality,
often referred to as product data management (PDM) applications,
are eliminated. [0029] Users have better data security of their 3D
Models, since there is only one master version of the data with no
copies being made as in traditional single-user CAD systems [0030]
Users work is continuously saved without the need for using a Save
command [0031] The system is fault-tolerant, so that even if a
portion of the system crashes or stops functioning the users use of
the system is not interrupted and the user's work on the 3D Model
is not lost [0032] Users receive real-time feedback ("Collaboration
Cues") showing which other users are also editing the same 3D Model
including feedback specific to parametric features, such as which
parametric 3d feature, parametric or variational sketch, parametric
dimension value, or 3D assembly mating relationship other users are
editing [0033] Large (and small) 3D Models show updates quickly to
all users, even if they distributed around the world on a wide-area
network such as the public internet [0034] Users achieve high-speed
3D Model operations due to distribution of computing work across a
network of computers and also by using CPU's and GPU's on each
user's client device [0035] Users may use Branching of 3D Models to
make changes that other users do not need to see [0036] Users may
later use Merging of 3D Models to combine branched changes back
into 3D Models that other users have changed [0037] Users can
visualize a textual and/or graphical view of who has performed what
work when on a 3D Model, including individual edits, versions,
branches, and merges [0038] Users can restore earlier states of a
3D Model, including states that existed before other users
performed edits on the 3D Model [0039] Users with touch-screen
tablets, phones, wearable computing devices, or other touch-based
computing device, can use a touch-based user interface, 2D and 3D,
to simultaneously edit the same 3D Models with users using web
browsers and mice or trackpads [0040] Client software within a
browser allows use without installing any software on the client
device [0041] At any time, a user can designate an autosaved
immutable state of the 3D Models on any branch as a named version
without requiring creation of files
[0042] The solution utilizes a Compound Document approach, with
additional benefits: [0043] An entire product design of arbitrary
size can be stored in a single Compound Document [0044] All CAD
data (parts, drawings, assemblies, etc) and non-CAD data (PDF
files, Word processing files, spreadsheet files, image files,
videos, etc.) can be stored as "Tabs" in one compound Document
[0045] CAD data in multiple native CAD formats from multiple
different CAD systems can be stored together in a single Compound
Document [0046] Links between data objects, for example an assembly
that references a part, are not dependent on often-fragile computer
file system naming and folder structures. Thus the user cannot
disrupt the state of their CAD data through inadvertent renaming
files, reorganizing folders, or copying files in a computer file
system. [0047] An entire Compound Document can be shared with
another user for collaboration with only one sharing operation,
without the need for many sharing operations to share individual
data files, or create a separate "Project" file, or use a separate
(PDM) system or servers [0048] The entire Compound Document can be
version controlled in a single operation without the need for
multiple version control operations for each of many individual
files [0049] A user is guaranteed to be looking at the correct
matching versions of all elements/Tabs in a product design since
they are all stored and versioned together in one Compound
Document. [0050] External non-native CAD files that are stored in
Tabs in a Compound Document are available to download to recreate
exact copies of the original files [0051] Non-native CAD files
stored in a Compound Document can be translated into the native CAD
format of the Compound Document-based CAD system via a new
additional native CAD data Tab. The original non-native CAD files
remain part of the Compound Document, even after translation, and
are thus available to all users with access to the Document and can
be downloaded again at any time.
[0052] A Reference Manager tracks references to instances in order
to maintain design integrity if an instance is separately changed.
This adds benefits: [0053] Back-up geometry is maintained to
prevent changes in one parametric history breaking design in
another parametric history [0054] Users are made aware of changes
non-intrusively [0055] Extraneous and inadvertent relationship
updates are prevented [0056] Users can control what is updated and
immediately correct any inconsistencies and prevent inadvertent
changes [0057] Cases that fail in conventional systems are stable
because the existence of back-up geometry enables robust
regeneration
[0058] A history manager tracks changes across multiple versions
and workspaces for a design project. This enables: [0059] Visual
text and graphical comparison of prior history or different
versions of a CAD design [0060] A workspace and version graph for
an entire CAD design [0061] Restoring a previous state is tracked
as an entry in history [0062] Visual comparison of 3D model
side-by-side differences or merged state is available at every
change, allowing incremental merging [0063] Previous merges and
restores are accounted for when merging
[0064] Client-server performance enhancements allow adjusting what
is calculated by the server and when those calculations occur, to
maximize client performance for users. This includes: [0065]
Inferencing calculations based on current user views and user
interface control positioning, with a client-side non-visible
buffer holding received inferences [0066] Derivative solver
estimates provided from the server to a client to simplify
calculations and allow predictive geometries to display during user
interface interactions [0067] Smooth user interface operation
occurs independent from latency between a client and a server as
well as scale and complexity of a model
BRIEF DESCRIPTION OF THE DRAWINGS
[0068] In the drawings, closely related figures and items have the
same number but different alphabetic suffixes. Processes, states,
statuses, and databases are named for their respective
functions.
[0069] FIG. 1 is a system overview diagram.
[0070] FIG. 2 is a flowchart showing the startup process for a
server.
[0071] FIG. 3 is a flowchart showing the server selection process
when opening a project.
[0072] FIG. 4 is a flowchart showing server interaction during a
typical user edit within a project.
[0073] FIG. 5 is a screenshot of the projects overview.
[0074] FIG. 6 is a tabbed document screenshot.
[0075] FIG. 7 is an upload screenshot.
[0076] FIG. 8 is a download screenshot.
[0077] FIG. 9 is a translate screenshot.
[0078] FIG. 10 is an export screenshot.
[0079] FIG. 11 is a properties screenshot.
[0080] FIG. 12 is an editing dialog screenshot.
[0081] FIG. 13 is a sketching mode screenshot.
[0082] FIGS. 14, 15, & 16 are screenshot showing
inferences.
[0083] FIG. 17 is a flowchart detailing predictive drag.
[0084] FIG. 18 is an assembly screenshot.
[0085] FIG. 19 is a measuring properties screenshot.
[0086] FIG. 20 is a mass properties screenshot.
[0087] FIG. 21 shows the history.
[0088] FIG. 22 shows the version manager.
[0089] FIG. 23 shows sharing a project.
[0090] FIG. 24 shows multiple users working simultaneously within
the same workspace.
[0091] FIG. 25 shows code representation opened while CAD
editing.
[0092] FIGS. 26A & 26B show part edges defining the edges of
another part.
[0093] FIG. 27 shows one part with a feature defined by the
geometry of another part.
[0094] FIG. 28 shows detection of out-of-sync references.
[0095] FIG. 29 shows resolving out-of-sync references through
synchronizing.
[0096] FIG. 30 shows resolving out-of-sync references through
dismissing.
DETAILED DESCRIPTION, INCLUDING THE PREFERRED EMBODIMENT
[0097] In the following detailed description, reference is made to
the accompanying drawings which form a part hereof, and in which
are shown, by way of illustration, specific embodiments which may
be practiced. It is to be understood that other embodiments may be
used, and structural changes may be made without departing from the
presented scope.
Terminology
[0098] The terminology and definitions of the prior art are not
necessarily consistent with the terminology and definitions of this
disclosure. Where there is a conflict, the following definitions
apply.
[0099] Assembly--used to assemble parts. An Assembly is used to
define the structure and behavior of an assembly. Each Assembly has
its own Feature list that contains Instances (of parts and
sub-assemblies), Mates, Mate Connectors, Groups, and Relations.
[0100] Back up geometry--reference to prior geometry which has been
changed.
[0101] Branch--workspace for a specific version of a project.
[0102] Client Device--computer hardware, such as a desktop
computer, tablet, phone, or wearable computer such as glasses or
watch, used by a user of the system for three-dimensional
multi-user computer aided design.
[0103] Client Program--software program running on a client device
to access the multi-user cloud CAD system and to provide an
interface to a user for interacting with the multi-user cloud CAD
system. The software program may be a dedicated application or a
web-page driven interface running within a browser.
[0104] Compound Document--a single data structure which is actually
made up of any number of internal components which traditionally
would be stored as separate files.
[0105] Compound inference--an inference that is composed of
multiple inferences.
[0106] Constraint--a relationship between two geometries that
mutually limits their positions, e.g., a "coincident" constraint on
two points will result in the points having the same location.
There are many types of constraints, such as coincident, parallel,
perpendicular, tangent and so on. Constraints are logical
relationships between geometries. For example, a "parallel"
constraint between two line segments will ensure that the two line
segments are parallel.
[0107] Degrees of freedom--data associated with geometry that
explains how (if) that geometry may be repositioned by the solver.
For example, a point may be constrained to lie on a fixed line. In
such a case its degrees of freedom is translation along that
line.
[0108] Derivatives--the approximation of the rate of change of a
sketch state vector with respect to a dragged geometry state
vector.
[0109] Dragged Geometry--the geometry being dragged by the user,
where dragged means that the user is moving the geometry in some
way, such as by clicking and dragging with a mouse or dragging with
a finger or stylus on a touch enabled device.
[0110] Dragged Geometry State Vector--a subset of a sketch state
vector that represents the dragged geometry.
[0111] Features--rules or properties configured for a part or an
assembly. Features may reference other features as part of their
definition.
[0112] Feature List--In Part Studios: a parametric history of work,
containing features, parts, and a Rollback bar to view work at a
certain point in the parametric history; In Assemblies, the Feature
list contains an Assembly Instance tree structure, Mates, Groups,
and Mate connectors.
[0113] Geometry--solid bodies, surfaces, axes, curves, or points
and other pieces of shapes that the user can manipulate and which
the software will reposition to satisfy constraints. For example, a
line segment is a line (straight curve) between two points.
[0114] Persistent Transaction History--a set of retained states of
all tabs (Part Studio, Assemblies, etc.) of a workspace at each
persisted change made within any tab.
[0115] In-context reference--within a CAD design program,
references that are relationships between geometric objects that
are created in separate parametric histories in the context of an
assembly are referred to as "in-context" references.
[0116] Instance--a reference within an Assembly to either a part
defined in a Part Studio, or to a sub-assembly defined in another
Assembly.
[0117] Inference--a constraint that is detected during sketching
and which can be added to the model when geometry is created or
repositioned. For example, when drawing a new line, a coincident
inference might be found between an end of that line and an
existing point in the model.
[0118] Mate--a high-level entity used to position instances and
define how the instances move (e.g., define movement between parts
and/or sub-assemblies).
[0119] Mate connectors--local coordinate system entities located on
or between parts and used within a mate to locate and orient
instances with respect to each other (define where instances
connect).
[0120] Model--the 3D geometry that is the result of the geometric
operations.
[0121] Out of sync reference--when referenced geometry or the
context that defines the position of referenced geometry changes,
the "in-context reference" is called "out of sync".
[0122] Parametric history--ordered list of features that when
regenerated in order creates geometry of one or more parts.
[0123] Part--a named geometric construction, which can be combined
and constrained with other parts to create an assembly.
[0124] Part Studios--where a user creates parts. A Part Studio
contains a Feature list (parametric history) and a list of Parts
generated by that feature list.
[0125] Project--a Compound Document within the 3D CAD system.
[0126] Reference--relationship between design geometry.
[0127] Sketch--a collection of 2D geometry and constraints, on a
plane.
[0128] Sketch State Vector--a vector of numbers that represents all
of the geometry in a sketch.
[0129] Sketching--the action of modifying a sketch.
[0130] Sketcher--a software component that the user uses to create
and manipulate geometry and constraints.
[0131] Solver--a software component used by the sketcher that takes
a collection of geometry and a collection of constraints and
repositions geometry as necessary to satisfy the constraints.
[0132] Snap--adjustment of geometry so that it coincides with an
inference.
[0133] Surfaces--Surfaces individually or in sets can be parts or
construction entities, and may be used or referenced by various
sketching and part modification tools in order to alter or create
parts.
[0134] The System--one or more interconnected or network connected
servers working with one or more Clients across network connections
to operate multi-user parametric feature based three-dimensional
computer aided design.
[0135] Tab--represents an individual design or documentation
component stored within a compound document for a project. For
example, a tab could represent a Part Studio, an Assembly, a
Drawing, or an uploaded file such as a pdf, image, video, or any
file stored as it would be in on a computer disk.
[0136] Version--a named state of a compound document. Versions are
immutable and separate from workspaces. To capture a workspace at a
particular point in time, a user can save it as a version.
[0137] Workspace--An active modeling/design space.
[0138] Operation
[0139] The Multi-User Parametric Feature Based 3D CAD System
("System") is constructed in several parts. Sets of computers
("Servers") perform 3D geometry calculations, manage CAD editing
workflow, and manage interactions between user client devices
(computers, tablets, phones) and the CAD editing servers. Client
programs operate on client computing devices to display a graphical
interface for CAD editing. The client program may be a dedicated
software program or application stored on the client device, or
loaded on demand such as within a web browser. A network and system
of communication passes asynchronous messages among these Servers
and the client software. 3D information flow is optimized for rapid
model and change dissemination.
[0140] Hardware/System Overview
[0141] Referring to FIG. 1, multiple servers communicate with each
other and with client devices. As shown in FIG. 1, such
communications occur across internet 165. This is preferred,
because it extends use anywhere the internet is accessible, but may
alternatively be replaced with any network connecting the servers
with each other and to client devices. Similarly, individual
servers are shown as separate physical devices. These servers may
be combined to run on shared devices, or connected internally, but
the depicted configuration is preferred to allow geographic
distribution of the various servers. The servers shown may be run
in multiple mirrored copies distributed geographically, allowing
optimization for user connection and performance regardless of
location. Each individual copy of a server may be run on a single
physical computer, across multiple physical computers (such as a
cluster or server farm), or run on one or more physical computers
shared with other servers. Each server preferably has dedicated
physical resources of eight or more 64-bit, or better, central
processing units (CPU's), with eight or more gigabytes (GB) of
memory, and a high-speed one gigabit per second or faster network
connection between the various servers, although geographic
separation across the internet may slow connections (such as
between a client and the servers, or between mirrored servers).
[0142] Servers
[0143] 3D Geometry Calculation Servers ("3DGCS") 100 run software
including, but not limited to, 3d geometry kernels such as, but not
limited to, Parasolid or ACIS; 2d and 3d constraint solvers such
as, but not limited to, DCubed DCM2D and DCM3D; and other software
that performs geometry calculations to modify computer
representations of geometric shapes (for example, but not limited
to, drilling a hole or rounding edges), that analyzes the shapes
(for example, but not limited to, computing volume or surface
area), and creates optimized 3D graphics data such as, but not
limited to, triangular facets that may be sent to one or more
clients via a CAD editing workflow server over a networking
protocol in order to display a 3D image of the object being
designed.
[0144] CAD Editing Workflow Servers ("CEWS") 105 run software
including, but not limited to, an operating system such as Ubuntu
or other Linux variant, a web application written in a language
such as Java, web application components such as Jetty and Spring,
and other software. CEWS receive messages from Client computers and
processes over a networking protocol to read and write CAD data
from data persistence servers, to perform CAD functions such as
modifying CAD features or metadata, coordinate collaboration among
users using multiple Clients, and communicate with 3DGCS to do
geometric modeling operations for a project. CEWS also, upon
request from a Client, send to that Client a set of Client
application software such as JavaScript coding that may include 3D
WebGL "shader" programs, plus other JavaScript program utilities
such as Angular, for operation on the Client device.
[0145] Security Credential Management Servers ("SCMS") 110 run
software including, but not limited, to an operating system such as
Ubuntu or other Linux variant and software that manages credentials
for access to the System. The SCMS is also used to centrally manage
authentication credentials and authorization rules for secure
access to the computers in the System by operations personnel such
as systems administrators.
[0146] 2D Drawing Editing Workflow Servers ("2DDEWS") 115 run
software including, but not limited to, an operating system such as
Ubuntu or other Linux variant and other software that allows
Clients to create and manipulate 2D drawings of their CAD models.
The software allows the user to create drawings with cutaway views,
precise dimensions, and other drawing items which provides
information for the CAD design to be manufactured by a third party
and for other purposes.
[0147] Data Cache Persistence Servers ("DCPS") 120 run software
including, but not limited to, an operating system such as Ubuntu
or other Linux variant and commercial or open-source software that
allows other components of the System to very quickly store and
retrieve data that is frequently accessed such as CAD model
information and graphical "thumbnail" representations of CAD models
and assemblies.
[0148] Document Management Web Servers ("DMWS") 125 run software
including, but not limited to, an operating system such as Ubuntu
or other Linux variant and commercial or open-source software such
as Jetty, Spring and other software written in the Java programming
language. DMWS are Internet-facing (optionally through a network
load balancer) servers that take network requests from clients in a
REST protocol format and reply with information about the user's
own CAD projects and projects that the user has the authorization
to view. The user can also manipulate CAD projects (for example,
but not limited to, create, delete, share, and rename) through
communications with DMWS.
[0149] Asynchronous Message Broker Servers ("AMBS") 130 run
software including, but not limited to, an operating system such as
Ubuntu or other Linux variant and commercial or open-source
software such as RabbitMQ and other software written in the Java
programming language. AMBS take messages sent from the DMWS, CEWS,
and other Servers, and distribute those messages to asynchronous
message consumer servers in specific geographies for processing
based on the type of message. This allows for background processing
and a high degree of scalability. Additional AMBS can be
dynamically added or removed as system-wide processing needs
demand.
[0150] Asynchronous Message Consumer Servers ("AMCS") 135 may have
lower physical resources (fewer or slower CPU, lower amounts of
RAM) than other servers depending on the specific role that an AMCS
is performing. AMCS run software including, but not limited to, an
operating system such as Ubuntu or other Linux variant and
commercial or open-source software such as Jetty, Spring and other
software written in the Java programming language. An AMCS takes
messages from an AMBS that are specific to a particular role, and
processes those messages. Example AMCS roles include, but are not
limited to, processing graphical display data generated from the
3DGCS and creating thumbnail images, translating to and from
industry standard and other CAD system file formats, and sending
user notification emails when projects are shared. AMCS communicate
via secure network protocols with data persistence servers and
other external services. Additional AMCS can be dynamically added
or removed as system-wide processing needs demand.
[0151] Data Persistence Servers ("DPS") 140 run software including,
but not limited to, an operating system such as Ubuntu or other
Linux variant and commercial or open-source software like mongoDB
to persist user login account information, user CAD projects, user,
project, and system metrics, and other information saved on behalf
of the user or the system.
[0152] Performance and Health Monitoring Servers ("PHMS") 145 run
software including, but not limited to, an operating system such as
Ubuntu or other Linux variant and commercial or open-source
software such as, but not limited to, logstash, elasticsearch,
kibana and zabbix. PHMS continually collect performance and health
data from other servers in the System via networking protocols.
This data is transmitted via TCP and UDP networking protocols from
all other servers running in the system, and is used to provide
insight into user behavior, hardware and software failures and
system performance.
[0153] Distributed Configuration Controller Servers ("DCCS") 150
are preferably run in a clustered configuration in a Core data
center. DCCS run software including, but not limited to, an
operating system such as Ubuntu or other Linux variant and
commercial or open-source software such as, but not limited to,
zookeeper and puppet. DCCS provide a tree-like persistence
mechanism where other servers, including DMWS, 2DDEWS, and CEWS,
can read and write configuration keys and values and can listen for
notifications if those keys or values (or their children in the
tree) change. DCCS provides configuration to all of the other
severs in the System. This allows for centralized management of
configuration and ensures that configuration is consistent across
servers and copies of each server. DCCS also provides service
discovery. Each server in the System depends on services provided
by other computers in the System. Referring also to FIG. 2, when a
server (other than DCCS) is started 200, it connects 210 to and
queries 220 the DCCS for the network location for the other needed
services, and when the server is fully operational (startup
complete) 230 it advertises 240 its own availability through DCCS.
DCCS also provides CEWS locations for open projects in order to
enable collaboration between CAD users. Referring also to FIG. 3,
when a user opens 300 a specific project, the DCCS checks 310 to
see if that project is already opened on a specific CEWS. If so,
the opening request (as well as further project editing actions) is
directed 320 to the specific CEWS, ensuring all users actively
working on the same project do so through the same CEWS. If not,
the DCCS selects 330 a CEWS (such as based on geographic location,
or current server loads, or other performance-focused criteria) to
direct the request and open the project, and registers 340 in DCCS
a listing of a project identifier associated with the specific
selected CEWS.
[0154] Distributed Search Servers ("DSS") 155 are preferably run in
a clustered configuration in a Core data center. DSS run software
including, but not limited to, an operating system such as Ubuntu
or other Linux variant and commercial or open-source software such
as elasticsearch. DSS provide both data indexing and a search
mechanism for locating projects, parts, users, etc. from a query
string.
[0155] Background Upgrade Servers ("BUS") 160 are preferably run in
a parallel configuration in a Core data center. BUS run software
including, but not limited to, an operating system such as Ubuntu
or other Linux variant, a web application written in a language
such as Java, web application components such as Jetty and Spring;
and other software. BUS are used in conjunction with 3DGCS at
software upgrade time to iterate over all existing CAD projects,
upgrade any structures in those projects so that they work
correctly with the new software and verify that the upgrade process
has not damaged the geometric integrity of the CAD projects.
[0156] Users connect through a client program running on a client
device. Many different servers may interact, depending on the user
action. Initial user connection and verification (secure
identification) involves SCMS. Once connected and editing a
project, a network websocket connection is established between the
client and a CEWS for the opened projected. The CEWS manages user
editing and view change actions, while asynchronously sending
requests to other servers as needed. Referring also to FIG. 4, in
an editing example, the client sends 400 the CEWS a editing message
with an identification of a feature being edited, and details about
a change. The CEWS asks 410 the DPS to record the edit as an
increment on a project branch the user is working on, including 415
a timestamp and user identification. If there have been too many
increments since the last full (non-incremental) record, the CEWS
asks the DPS to write a full record (as an optimization). The CEWS
also sends 420 the edit information to all clients connected to the
project (so that they can appropriately update indications about
the edit). The CEWS checks 430 if it is connected to a 3DGCS that
is available and recently regenerated the part studio in a similar
state. If not, the CEWS asks 440 the DCCS for a 3DGCS server and
asks it to launch a new 3DGCS process. With a 3DGCS appropriately
available, the CEWS sends the change to the 3DGCS (and more project
data if needed by a newly available 3DGCS), and generates or
regenerates 450 a model based on the changes. The 3DGCS sends 460 a
tessellation increment (triangles, polylines, etc), error state,
and other graphics data about the features it regenerated back to
the CEWS. For each client connected to the project, the CEWS sends
470 back the tessellation and other increments. Because the clients
may be in different states, the increments they need may be
different and the CEWS computes the appropriate ones for current
display on each connected client. If there are, for example,
assemblies in the same project referencing a changed part, the CEWS
updates these assemblies. This may involve asking 480 3DGCS to
solve the assemblies and DPS to record 490 the changes. The CEWS
sends changes to the assemblies to all clients connected to the
assemblies.
[0157] Client
[0158] Users interact with the system through one or more clients,
each running on a client device 170. Different client programs are
designed to allow users to work on CAD projects from different
client devices. For example, a user may start a CAD project in a
web browser on a desktop computer at work, continue updating the
project on the road using a mobile phone, and finish the project on
a computer tablet at home. This enables system access and operation
from any computing device and from anywhere there is an Internet
connection.
[0159] Client programs can be generally be classified as either web
clients designed to work within a browser through HTML, CSS,
JavaScript, and WebGL, or native applications designed for specific
platforms such as mobile phones, computer tablets, and other
internet appliances and with operating systems such as, but not
limited to, iOS and Android. Native applications may implement
communications to servers matching the communications performed by
web clients, while optimizing appearance and/or interactivity (such
as user input and control) specific to an individual platform or
line of computing devices.
[0160] Web Client
[0161] Web clients run inside standard browsers such as, but not
limited to, Chrome, Firefox, Safari, Opera, and Internet Explorer,
using HTML, CSS, JavaScript, and WebGL. This allows operation
without any required installation or plug-in on the client device
operating the web client. The web client is light weight and may
work with a large number of devices, including, but not limited to,
computers, Chromebooks, televisions, gaming consoles, and other
Internet appliances. Web clients work with any WebGL compatible
browser, such as, but not limited to, Safari, FireFox, and Chrome,
running on any computing device with WebGL compatible graphics
hardware.
[0162] Apps
[0163] Native applications (Apps) are built for dedicated system
platforms, such as, but not limited to, Apple iOS, Android, and Mac
OS X. Apps require download and installation, so in many cases may
be less desirable than web clients, but can take advantage of
platform-specific features. These apps can be installed on devices
such as, but not limited to, computers, tablets, smart phones and
other wearable devices like watches and google glass. Apps are
designed to provide the best experience possible for a given
platform, for example, by optimizing user interaction for the size
and orientation of the device's display area, and for unique
capabilities such as but not limited to touch interaction and
accelerometers.
[0164] For example, the iOS app operates on Apple mobile devices
including iPhone and iPad. This app utilizes dedicated platform
features, including touch gestures, Wi-Fi and cellular networks,
and device notifications. For performance and graphics
capabilities, the iOS app requires iOS 7 or above.
[0165] As another example, the Android app operates on mobile
devices running an Android operating system, and, similar to the
iOS app, utilizes dedicated platform features including touch
gesture control and device notifications. The Android app works
with any Android device supporting KitKat or LollyPop or above.
[0166] Specific Process Details
[0167] Overview
[0168] The multi-user cloud-based 3D CAD system presents an editing
user interface (UI) for users to design, modify, and share
structures. For each user, the system begins with authentication,
and then presents various projects to the user. Each project is for
the design of one or more structures, or assemblies, which is made
up of a collection of instances of parts and sub-assemblies. Each
project is made up of multiple data units, referred to herein as
tabs, representing the assembly, parts, and other data desired as
part of the project. A history of actions, or persistent
transaction history, is associated with each project, and the
histories may be branched to allow multiple workspaces (and
different end assemblies) within the same project. Projects may be
shared with multiple users, allowing concurrent editing to
occur.
[0169] Authentication
[0170] A user begins use through a client device. The figures and
examples discussed herein generally refer to the web client with
browser access such as through a desktop or laptop computer, but
the same concepts, operations, and interactions with the servers
and user interfaces apply to dedicated apps on any client device,
such as a smart phone or tablet, with input controls changed to
match those used with the specific device.
[0171] A first step may include authentication of the user through
the client. A preferred embodiment is through input and
verification of a username and password, but alternative forms of
secure authentication (for example, but not limited to, two stage
authentication or biometric authentication) may be used. A web
client may provide an authentication page from the DMWS, while a
dedicated app may generate an authentication page (or retain
authentication information). The authentication information may
pass to the SCMS, and after authentication the DMWS, in conjunction
with the DPS and DCPS, may present an overview page for display by
the client (or overview information for display through a dedicated
app). Alternatively, this may be configured to be a different
initial view, such as to present the last view of the user at the
most recent prior session.
[0172] Projects
[0173] Also referring to FIG. 5, the overview presents various
management options as well as access to projects. Within this
system, each assembly is retained with all related data
(subassemblies, part studios defining parts, and other tabs) in a
single compound document (as later detailed). Thus, the interface
shown in FIG. 5 refers to projects as documents (notably, "My
Documents" 500).
[0174] Within the overview, profile management options may allow
setting basic information, such as name, company, contact
information, and account password. Additionally, default settings
may be configured, such as units to use for length, size, or
angles. Default settings will apply unless specifically configured
at a lower level (such as at a project, workspace, or tab level).
The overview may present information about one or more projects,
such as name 510, creator 520, last modification 530, and a small
or thumbnail visualization 540 may be presented, along with global
account information such as last access, total storage use, and any
account restrictions such as storage or computational time
remaining.
[0175] Projects may be listed in various configurable views, such
as recently accessed projects, projects created by the account
user, projects shared with the account user, and public projects.
Each project may provide options to view versions, history, control
sharing, delete the project, or open the project for editing.
[0176] Project Structure
[0177] Each project is able to store an entire and unlimited-size
collection of CAD parts, assemblies, drawings, and arbitrary other
CAD and non-CAD data. This collection is stored as a Compound
Document by DPS, and it may be shared and/or versioned. As a
compound document, it is stored as a single data structure which is
actually made up of any number of internal components referred to
as tabs, which traditionally would be stored as separate files on a
computer disk or storage unit. Referring also to FIG. 6, when
viewing a specific project, the internal components are accessible
as separate individual tabs 600 accessing individual panes within a
project workspace, with each internal component having its own tab.
This allows bundling CAD data (such as parts 610, drawings, and
assemblies 620) as well as non-CAD data 630 (for example, but not
limited to, PDF files, word processing files, and spreadsheet
files) into a single project. Management and sharing is simplified,
as links between CAD objects, such as an assembly referencing a
part, are references internal to the document and not dependent on
any file system naming or structure. Users sharing an entire
project share access to that single compound document, ensuring all
shared users have the same environment with correct references.
File system actions, such as users moving or renaming files or
folders, do not risk impacting the project due to the single
compound document. Versioning (and change tracking) is done at a
project level, so automatically applies (and is tracked) across all
internal components of the project. This avoids potential conflict
of incorrect versions of individual files, and simplifies
management by avoiding need to separately track changes and
versions of every file involved. This also guarantees that every
user accessing a project has the correct matching versions of all
elements/tabs, as the tabs are all stored and versioned together in
one Compound Document. For use with other systems, or selective
distribution, individual tabs may be downloaded as individual
files, with such download becoming separate and unlinked from the
entire project. Various export or translation options are available
for CAD-format tabs, and non-native CAD files that are stored in
tabs of the project are available to download to recreate exact
copies of the original files.
[0178] References may also cross projects. For example, an assembly
in one project may reference a part defined in another project. All
cross-project references reference only reference data objects that
exist within versions. Because versions are immutable, changes to
the reference project can never inadvertently change the
referencing project. The user receives notifications when new
versions become available and may then choose to update or not
update.
[0179] Client user interface controls may allow uploading,
downloading, and translating CAD Data. The system allows users to
upload and download CAD files into project tabs as Part Studios,
Assemblies or as exact file copies, to translate CAD data, from one
type to another, and to export as CAD files.
[0180] Upload allows uploading any type of file from a location in
local storage, network storage, or cloud services such as Dropbox
or Google Drive, that is addressable by the client device, into the
system, stored within a project by the DPS. Uploaded files may be
stored into an existing project, or into a newly created project.
How the system handles an upload depends upon where the upload was
initiated. If initiated from the Projects overview, the upload
creates a new Project with appropriate tabs. Also referring to FIG.
7, if initiated from inside a Project, or to a specific Project,
usually a new tab specific to the type of file upload is created
within the Project. Every file uploaded 700 into a project usually
becomes its own tab, named with the original file name. If the file
is a CAD file, appropriate Part Studio, Drawing and/or Assembly
tabs for that CAD file may also be created via CAD data translation
by the system. Any type of file can be uploaded into the system,
although file types not understood by the system may lack
functionality or display capability within the client. In addition
to uploading existing files, new and blank part studio 710 and
assembly 720 tabs may be created.
[0181] Download copies any file that was previously uploaded into a
project back out in its current file format to a storage
destination addressable by the client device. Also referring to
FIG. 8, downloads 800 can be initiated through context menus of
tabs within projects, and are available for any tab that can be
represented as a file.
[0182] Also referring to FIG. 9, translate 900 allows converting a
part studio, drawing or assembly file into a different format, and
displays as a new tab within a project. Translate may apply to any
default tabs (Part Studios or Assemblies) as well as any uploaded
CAD files. Some example translatable formats include, but are not
limited to, Parasolid, ACIS, STEP, IGES, CATIA v5, SolidWorks,
Inventor, Pro/ENGINEER, CREO, and JT. When a CAD file is uploaded
as a new Project, processing options are automatically presented.
When uploaded into an existing project, a translate option may be
selected to automate options. When translating a CAD file, options
are presented to select from vendor-specific or generic CAD
formats, and to specify options such as source orientation. Some
three dimensional CAD systems use a "Y Axis Up" coordination
system, while others use a "Z Axis Up" system. Additionally, if the
file is an assembly, or contains an assembly, another presented
option is to translate the file as only a Part Studio, which is
selected through a Flatten option. With the Flatten option
selected, the assembly is flattened to a set of parts in a Part
Studio. Translation and flattening are performed through
communication between the client and DMWS, DPS, AMCS, AMBS, and
CEWS. Non-native CAD files in a project may also be translated into
a native CAD format. This creates a new tab for the translated CAD
file, and retains the original non-native CAD file as part of the
project (which may be desired for future download in the original
format version).
[0183] Export translates a Part Studio (or individual part) to a
format, for example STL format, and downloads it to a storage
location addressable by the client device. Referring also to FIG.
10, users have the option of exporting either an entire Part Studio
or individual parts within a Part Studio to an STL or other type of
file 1000.
[0184] Editing a Project
[0185] Once a project is opened by a client, each tab represents a
file within the single compound document of the project. Opening an
existing project opens tabs for all files within that project.
Creating (and opening) a new project starts the project with a
default workspace and default tabs, for example a Part Studio and
an Assembly. The tabs may be rearranged (ordered positioning), and
this action applies to the workspace (so would also be applied to
any other users collaborating on the same workspace). Which tab is
currently active, and any positioning/scrolling of the workspace,
are user-specific and non-persistent. Therefore each user
collaborating on a project workspace has their own active tab and
their own tab scroll state. Options for each individual tab,
accessible through the user interface, may include renaming the
tab, viewing and editing tab properties (such as, but not limited
to, description; part number; revision; state of a part),
duplicate, copy to clipboard, export to STL, translate, and delete.
Duplicate creates a new tab with an exact copy of the duplicated
tab, with each of the duplicate tabs being independent. Thus
changes in the copy do not impact the original tab. Translate
similarly creates a translated copy in a new tab, leaving the
original formatting in the previously existing tab.
[0186] A project menu, also accessible through the user interface,
allows project-wide options such as to rename the project, copy the
current workspace, view or change properties (such as default
units), print, access versions and/or persistent transaction
history, and undo or redo actions.
[0187] Metadata
[0188] The system allows users to create and edit meta data for
parts, Part Studios, Assemblies, Drawings and foreign data (non-CAD
tabs) in order to support various design processes. Referring also
to FIG. 11, metadata may include a description 1100, part number
1110, revision 1120, and state 1130 (in progress, pending,
released, or obsolete). Metadata is defined and edited through the
Properties dialogs 1140 found on various context menus. Parts
metadata may be accessed and edited through a context menu on a
part listed within a Part Studio feature list. Part studio
metadata, assembly metadata, and foreign data file metadata may be
accessed and edited through context menus on individual tabs within
a project. Additionally, all types of metadata may be accessed and
edited through a properties dialog for a version or workspace
accessed through a Version Manager.
[0189] Workspace
[0190] The user interface workspace for an active project includes
a menu bar or user interface control button area, tabs for all
files in the project, a graphics area for the active tab, and a
feature list. The graphics area displays the active Part Studio,
Assembly, or other tab. The feature list has different data
depending on the active tab. If a part studio is active, the
feature list contains a parametric history of work, and a Rollback
bar to view work at a certain point in the parametric history. If
an assembly is active, the feature list contains the Assembly tree
structure, Mates, Groups, and Mate connectors.
[0191] User interface display and interaction with the workspace
may vary depending on the client device and input/output
capabilities. Typically, selection is done via click (or touch),
and may be added to by additional clicks. Click- (or
touch-)-and-drag also enables selection of multiple entities.
Different group selections may be possible. For example, the
direction of drag (and as indicated by a specific color of the
selection box) may toggle between selecting all entities entirely
within the box, and selecting all entities touched by the box.
Additionally, clicking (or touching) something already selected
de-selects it.
[0192] Dialog controls are used extensively, and many different
aspects of CAD design have different options to configure. Dialogs
are accessed through menu selection or right-click in feature list.
UI design of the dialogs may identify required selections through
highlighting (and selection may be made through the graphic area or
feature list). Referring also to FIG. 12, configurable properties
in dialogs 1200 may include different aspects, such as units input
as part of numeric inputs (which may override default or project
unit settings), number input in the form of mathematical
expressions (PEMDAS or trigonometric), or global variables and
equations. Dialogs may also include a preview slider as detailed in
patent application Ser. No. 14/226,042 (Previewing Changes On A
Geometric Design, filed Mar. 24, 2014, naming inventors K. Evan
Nowak and Michael Lauer), which is fully incorporated by reference
herein. When a user edits a feature, by default the model displayed
is rolled back to its state when that feature was created, hiding
all later features (with features sequentially applied from
top-to-bottom as listed in the feature list). The Final button 1210
displays the final result with later features applied while the
user is still editing the feature. If editing the last feature, the
user interface does not need to display the Final button, as there
are no later features to apply.
[0193] Graphic Area Controls
[0194] Within the graphic area, mouse or touch control may rotate
(3D), pan (2D), and zoom the active view. A view cube 1220 may be
also displayed, with user interface interaction with the view cube
adjusting the active graphic area view. For example, arrows around
the cube may rotate the view in any of six directions, selecting a
planar face of the view cube may change orientation to the plane,
and a dot or other indicator on the cube may auto adjust to an
isometric view. A view cube menu may allow further options, such as
isometric, dimetric, or trimetric; specific section views; zoom to
fit; toggling perspective; controlling shading and edges; and
adjusting translucency (transparency may also be set on a per-part
basis by changing appearance of selected individual parts).
[0195] Error Conditions
[0196] As part of dialogs and general user interface design,
visible error indicators are displayed in colored text. The most
common errors may be determined by 3DGCS or CEWS while editing a
part or assembly. For example, when there is a problem with a
feature, a user may see that feature in orange text in the Feature
list. Hovering over or selecting orange text in the Feature list
may further display a summary of the issue. With a dialog active,
the dialog title may be colored orange to indicate error. Within
the dialog, orange text may identify entities previously input into
a dialog box which have been deleted, or may identify error
conditions preventing application/operation of the dialog box. When
the problem lies with a single field, like an invalid entry in a
numeric field, that field may be outlined in red. Similar error
indicators may extend to sketching. Color may be used to indicate
the constraint status of sketch entities, for example, blue means
under-defined, black means well defined, and red means over-defined
(over-constrained). With constraints, standard coloring (such as a
gray square with a black icon inside) may indicate no error, while
color indicators (such as a red square with a white icon) may
indicate a problem with a constraint. If a more general system
error occurs, a notification may appear in a bubble at the top of
the user interface window.
[0197] Sketching
[0198] Sketching is an editing mode for editing geometric shapes
within a specific plane. The results of sketches are features which
are used to create parts for an assembly. Sketching is entered
while editing parts, and can be used to create geometric shapes
which become parts, or modify geometric shapes of existing parts.
Some options are the same whether sketching or editing parts and
features outside of sketch mode, but sketch mode also allows some
sketch-only options. Referring also to FIG. 13, a sketch toolbar
1300 with such options becomes active when creating a new sketch,
editing a sketch, or when selecting a sketch option. In all cases,
a specific plane is required to orient the view for the sketch. The
sketch toolbar contains tools to begin or edit a 2D sketch which is
used to create or modify a 3D feature or part.
[0199] Some of the sketch options include tools for basic geometric
designs. For example, lines 1302, rectangles 1304, polygons 1306,
circles 1308, arcs 1310, and splines (multi-point curves) 1312 may
be created or edited within the sketch plane. Basic geometry
constructs, such as lines, rectangles, and circles, may be created
by user interface interactions directly in the graphics area, such
as by selection or drag actions to set any endpoints, vertices, or
curve control points. More complex tools may also have dialogs to
set any required input or configuration (such as number of sides
for a polygon). Construction 1314 allows creating new geometric
constructions or converting existing entities into a geometric
construction. Additional tools may modify existing geometries. For
example, use 1316 or convert may project (or convert) one or more
edges of parts onto the active sketch plane. Fillet 1318 may create
fillets (rounds) along one or more lines, arcs, and splines. Trim
1320 may restrict a curve extension, and extend 1322 may stretch a
line or arc, to a first intersecting point or bounding geometry.
Offset 1324 may shift a curve or loop a specified distance and
direction from the original. Mirror 1326 may copy one or more
entities in the sketch plane, and mirror them across a selected
line. Dimension 1328 may add horizontal, vertical, shortest
distance, angular, or radial dimensions to sketch geometry.
Additional options allow constraints between multiple geometric
entities, thereby controlling shape and/or positioning. For
example, coincident 1330 makes two or more entities (lines, curves,
or points) coincident. Concentric 1332 makes two or more circles or
arcs share a common center point. Parallel 1334 makes two or more
lines parallel. Tangent 1336 forms a tangent relation between two
or more curves. Horizontal 1338 makes one or more lines, or sets of
points, horizontal within the sketch plane. Vertical 1340 makes one
or more lines, or sets of points, vertical within the sketch plane.
Perpendicular 1342 forms a right angle between two lines. Equal
1344 makes two or more curves of the same type equal in size.
Normal 1346 positions a line to be on a normal to a curve. Fix 1348
grounds a sketch entity on the sketch plane. To aid in positioning
and constraints, point 1350 may create points anywhere on a sketch
entity, allowing constraints to be fixed to such point. For
positioning control, midpoint 1352 constrains a point to the
midpoint of a line or arc. Some of the tool options create points
or constraints by default. For example, when fillet rounds multiple
lines, arcs, or splines, it adds (or retains) a coincident
constraint to keep the lines, arcs, or splines together. Similarly,
common points are automatically created with geometric entities
(such at vertices, ends of lines, and centers). These points may be
used in constraining geometric entities. Constraints are only
displayable and modifiable while in sketch mode, and may be
displayed with icons and colors through the user interface. Error
conditions with constraints can also be displayed, for example,
blue color may indicate under-constrained (more constraints
possible on a geometric entity), black color may indicate fully
constrained (no errors, but no alterations possible due to the
current constraints on a geometric entity), and red color may
indicate over-constrained (more constraints exist than can be
resolved into a valid geometric entity).
[0200] While sketching, inferencing occurs to guess at likely
constraints, display indication of such guess, and automatically
create the constraints if appropriate based on user input. One
example of this is horizontal or vertical alignment--when creating
or moving an entity, such as a line, if approximately horizontal or
linear to another entity, such as the point of origin, positioning
can automatically be made in vertical or horizontal alignment. This
automatic adjustment may be triggered by user action, such as by
holding a user interface element in one spot for a period of time
to indicate alignment is desired, disabled by user action, such as
holding a modifier to prevent any automatic inferencing, and
visually indicated within the interface, such as displaying dashed
lines to indicate alignment and inferenced constraint.
[0201] Inferencing
[0202] When sketching, a user often wants geometry to be related to
other geometry in a persistent way. Such relationships can be added
after the geometry is created. However, it is much more efficient
for the user to create such relationships dynamically, while
creating the geometry. Such dynamic constraints are often called
inferences or snaps because the visual appearance is that the
geometry being created visually snaps to existing geometry.
[0203] To perform the needed inferencing, the system performs all
the complex intersections and other geometric calculations on the
3DGCS, freeing the client from such work. While inferencing is
being calculated server-side, the client allows sketching to
continue, even while waiting for any server-side results. To
incorporate 3DGCS calculated inferences and geometric changes
seamlessly at the client, WebGL is used to process inferences. This
results in optimizations both client-side and server-side while
mitigating the communication time by providing a continuous user
experience on the client while the server is working.
[0204] To start inferencing, the client sends a request to
calculate inference targets. While waiting for the data from the
server (3DGCS via CEWS), the client provides user interface
functionality to the user, enabling continuing geometric edits but
not displaying any inferencing. When 3DGCS computes inference
targets, they are returned to the client and rendered to an
off-screen graphical buffer in WebGL. The inferences are returned
as an object containing an index to identify the individual
inference, an identity of an inference source (for example, a model
edge), one or more types of constraints applicable to the
inference, and an inference zone which provides a geometrical
description of an area that will snap to the inference (for
example, a point or a line). Client-side comparison between the
inference zones of inference targets in the WebGL buffer and user
interface interaction may determine which, if any, inferences
should be displayed to the user. Often the server responds before
the user has reached the location at which he wishes to place the
geometry, resulting in instant inferencing, but even when waiting
for server response the client-side user experience is
seamless.
[0205] When a user begins sketching, the client asks CEWS for any
inferences specific to the entity being drawn. Regardless of server
response, the client continues to update the displayed sketch based
on user input control (e.g., mouse control). Before server
response, such client updates occur without performing any snapping
(no inferences yet to snap to). When CEWS returns inference
information, the client checks the inference zones to find any
nearby inference, visually snaps geometries to matching inferences,
and displays to the user that a snap has been successful. When
geometry has snapped to an inference, the system adds corresponding
constraint(s) from the inference to the sketch. Table 1 below
outlines the client and server interactions for the case of
creating a point.
TABLE-US-00001 TABLE 1 Client CEWS & 3DGCS Receive user command
to start point creation To server: Start inferencing (type: point)
Repeatedly: Calculate inferences to sketch Process user input, such
as and model geometry and intersect moving the mouse non-point
inferences to produce compound inferences To client: Send
calculated inference Receive inference and updated WebGL inference
buffer Repeatedly: Process user input, such as moving the mouse.
Interrogate the WebGL inference buffer. If an inference is found
adjust the displayed position and display cues, indicating which
inference was found User places the point To server: Create a point
at a location. If a snap was in effect send the inference back to
the server. Received point creation command from client: Create the
point If an inference was also supplied then use the data within
the inference to create the constraint
[0206] This inferencing model applies to constraints inferred
between any geometric operation or creation, with point creation
illustrated as the clearest example to follow. Referring also to
FIG. 14, a sketch may appear to a user with a model face 1410 and
already drawn line 1400. Also visible to the user is global model
origin 1420. When the user enters a "point" command, the client
asks the CEWS to generate a list of inferences. This is needed as
the client doesn't have all the information needed to generate
inference data. Sending all of that information to the client, and
performing the mathematical calculations on the client, requires
time and computational power likely to introduce unacceptably large
delays in the response of the client.
[0207] While the server is generating the inference, the client
processes user input. When the client receives response from the
server, it processes that information to generate a selection
buffer in WebGL. The use of WebGL to perform inference picking is
significantly more efficient than iterating through all of the
inference data and performing mathematical operations to find a
match because graphics hardware is very good at processing a lot of
data in parallel. Referring also to FIG. 15, a visualization of the
geometry is drawn into the WebGL inference buffer. Four inferences
are highlighted in the figure, including coincident to edge 1500,
midpoint of edge 1510, and vertical to origin 1520. In addition, it
is often useful to snap to compound inferences. Compound inference
1530 is a combination of a coincident inference to the edge and a
vertical inference to the origin. By separating inference
calculation from the client, and continuing client operation during
inference calculation, the server is able to calculate the (many)
necessary intersections without affecting the client experience.
For every inference in the inference buffer, the client decides a
snap tolerance and renders a stripe or dot that incorporates this
tolerance. Once this buffer is drawn it can be sampled at the
position of interest.
[0208] If an inference is found at a position indicated by the
user, the client uses the inference data to determine how to
appropriately notify the user of the snap (e.g., by highlighting
the source of the inference and displaying an indicator showing the
type of inference) and modifies the position of the point to
conform to the snap. Referring also to FIG. 16, a newly created
point is snapped to the coincident inference and indicated to the
user through highlighting the inference source 1600 and display
coincidence indicator 1610.
[0209] When the user places the point, the client asks the CEWS to
create the point. If the client is currently snapping to an
inference, the client also passes that inference to the server.
When the CEWS receives the data, it creates the point and any
constraints related to the passed inferences.
[0210] This communication between client and CEWS is done as a
conversation. The client asks for the most immediately useful
inferences. As the user mouses over or otherwise moves model
geometry or view of the geometry, the client asks for additional
inferences related to that geometry. This conversation minimizes
the amount of calculations required without adversely affecting the
user experience. By updating the WebGL inference buffer
asynchronously on the server only when necessary (for example when
model geometry is changed) and much less frequently than inferences
occur (which usually happen locally entirely on the client), the
user experience is optimized.
[0211] Predictive Drag
[0212] As with inferencing, if the client waits for server
calculations while modifying any geometric model noticeable delays
may impact user experience. To avoid such delays, the client may
implement a predictive drag which estimates resulting geometries as
user interface movements (dragging geometries via a mouse or touch
control) are made. To enable such estimation, data is created by
the 3DGCS and CEWS which can be used as drag information by the
client. This drag information consists of two parts: data that
indicates certain ways in which the geometry is constrained to move
(degrees of freedom) and approximate derivatives of a solution
function. The 3DGCS runs a complete solution function when solving
geometries after client changes, but this includes complex
calculations beyond the scope of the client. The derivative
functions provide a less complex approximation capable of being
efficiently run by the client. The client, in turn, applies the
drag information constraints and derivate functions to approximate
sketch solutions, thereby updating the sketch in real time as users
geometrically drag elements in the sketch.
[0213] Asynchronous communications between the client and CEWS
allows updating the sketch shown on the client as it is solved
server-side, and also updating drag information appropriate which
accounts for any made changes. Referring also to FIG. 17, a
flowchart illustrates the logic and client-server interaction as a
user drags geometry in a sketch. If a user is not dragging 1700,
then no new dragging update requests are made to the server. When a
user makes a dragging action 1710 in the sketch, the client sends
1720 a modified state vector to the server. If the client has
derivate functions 1730, it locally calculates and updates 1740 the
graphical display using the derivative functions. The server, upon
receipt of a modified state vector, solves 1750 the sketch and also
calculates new derivative functions based on the newly solved
sketch. When the new sketch and derivative functions are received
1760 by the client, the locally tracked state and derivative
functions are updated 1770 and the current display redrawn 1740
with the server-solved sketch.
[0214] When solving the geometries of a sketch, through user
dragging or other geometric changes, a solver recalculates the
positions of all geometry to satisfy any constraints configured
within a sketch. Typically the set of constraints is complex (and
grow more complex and involved the larger and more complicated the
sketch), and the calculations can take noticeable time to complete
even when solved on a high-powered server. Each geometry is
represented by a vector of numbers. The vectors for a sketch can be
concatenated into a single state vector, which can be denoted as
x=[x.sub.1, x.sub.2, . . . , x.sub.n], a vector of n numbers. The
solver can be represented as a function f that produces a new
vector x that satisfies the constraints.
[0215] The client, given this vector x, displays the solved sketch
geometry to the user. A simple algorithm would involve the client
making changes to x, sending the changes to the server, waiting for
a response from the server with a new x, and updating the display
to show the solved sketch geometry of the new x. With any kind of
complexity in solving for the new x, the client appears sluggish
with time waiting for the update. To avoid such waiting behavior,
the 3DGCS uses finite differences to calculate approximate
derivatives of the function f. The derivatives of f with respect to
x.sub.i may be represented as df/dx.sub.i. The derivative
df/dx.sub.i may be calculated by first finding a suitable delta, h,
which is related to the size of the sketch. Then
df/dx.sub.i=[f([x.sub.0, . . . x.sub.i+h, . . .
x.sub.n])-f([x.sub.0, . . . x.sub.i-h, . . . x.sub.n])]/2 h.
[0216] Given a state vector x and the derivatives at x, df/dx, then
client calculates an approximation of the solve function f at any
other vector y by calculating y'=x+(y-x) df/dx. This may be used by
the client to estimate any geometry solves while actively modifying
the sketch by the user, thereby avoiding any delays in waiting on
the server.
[0217] On the client side: [0218] dfdx:=undefined [0219] x:=sketch
state vector [0220] approx:=x [0221] do [0222] do [0223] y:=new
state vector modified by user drag [0224] send y to server [0225]
if dfdx is defined then set approx:=x+(y-x)*dfdx [0226] draw approx
[0227] until server response received or user stops dragging [0228]
if server response received [0229] set x:=new state vector from
server [0230] set dfdx:=new derivatives from server [0231] until
user stops dragging
[0232] On the server side: [0233] when drag is received from client
[0234] calculate new sketch state vector [0235] calculate
derivatives with respect to coordinates being changed by the user
[0236] send new sketch state and derivatives to the client
[0237] This derivative approximation process may also be improved
with an additional step to use of degrees of freedom information,
which may be calculated by 3DGCS when calculating the sketch state
vector. Degrees of freedom information constrains the movement of a
dragged entity in a manner easily enforced by the client. As an
example of such constrained movement, if a point is constrained to
lie on a fixed circle then the client can enforce that constraint
before sending the change to the server, and before calculating the
approximation. This reduces variance in many cases.
[0238] The system can monitor, either entirely by the client or by
the server tracking timestamp data provided by the client, the time
required (delay time) from the client request through receipt of a
complete solution from the server. A large delay time may be caused
by a complex sketch or by a poor internet connection. In large
delay time situations, the system may enable use of predictive drag
dynamically to improve the user experience. A system wide setting
may be configured, or individual settings configurable at a user
account level, to establish a minimum delay time which, if
exceeded, triggers enabling use of predictive drag. If already
enable, dropping below the minimum delay time would trigger
disabling use of predictive drag. This dynamic
enablement/disablement improves the user experience, by allowing
continued local graphical operation and updating through use of
predictive drag when delay time is large, and reducing extraneous
graphical operation and updating by disabling predictive drag when
delay time is minimal.
[0239] Part Studio
[0240] A Part Studio tab is used to define parts and has a feature
list (parametric history). Regenerating the feature list produces
Parts. The feature list drives the shape of multiple parts. Each
part can be instanced multiple times in assemblies and each
instance can move independently in the assembly. There are two main
design tool aspects to the part studio: sketch tools and feature
tools. Because a Part Studio allows multiple parts to be defined
with one feature list, the user can design in a very productive
top-down manner.
[0241] Feature Tools are used to create parts through manipulation
of various features. The feature list includes entries referencing
the origin and planes 640, entries referencing created features
642, a rollback bar 1230, and entries referencing parts 644.
Created features are geometric operations (for example, but not
limited to, a sketch or an extrusion) and the specific data
associated with that operation. Selecting any entry in the feature
list accesses user interface options to hide or show the selection
within the graphics area, to suppress or unsuppress a feature
(which visualizes the model with or without the feature being
included), or to highlight the equivalent visuals in the graphics
area. The feature list is sequentially ordered from top to bottom,
so moving positions of features in the feature list reorders the
design parametrically, which can alter the resulting design.
[0242] Sketch Tools 650 add or modify features in order to alter
the displayed design. A specific sketch mode may be entered to
orient the graphics area view onto a specific plane or planar
surface, and then add or modify geometric shapes, points, and
various constraints. Whether or not in sketch mode, various other
options are available.
[0243] Extrude 652 adds or removes material perpendicular to a
selected region, surface, or planar face. A dialog allows
configuration of required entities, dimensions, and directions,
allowing creation or modification of parts, or intersecting an
extrude body with parts. Dimensions may be absolute (a measured and
specific distance) or relative, such as up to: a next geometry, a
specific surface, or a specific part; or through all parts.
[0244] Revolve 654 adds or removes material revolved about a
selected sketch planar face or edge. A dialog allows configuration
of required entities, dimensions, and directions to add a surface
from edges or curves or create, add to, remove from, or intersect
one or more solids. End conditions may be set such as a full
revolution (360 degrees around a selected axis), in one direction
for a specified angle, symmetrically in two directions for a
specified angle, or in two directions at specified angles for each
direction.
[0245] Sweep 656 adds or removes material along a specified set of
connected curves. A dialog allows configuration of required
entities, dimensions, and directions to add a surface or create,
add to, or remove material from parts.
[0246] Fillet 658 rounds sharp edges to create round outside edges
and filleted inside edges. A dialog allows configuration of
required entities and dimensions to apply a standard,
circular-shaped, constant radius fillet or a more stylized conic
fillet. Required aspects include a specific edge or face of a part
(which may apply to all edges of the face) and a radius value.
Alternative options include tangent propagation (to automatically
extend the fillet to tangent edges) or conic to apply a rho value
for a more stylized fillet (allowing parabolic, elliptical, and
hyperbolic curves).
[0247] Chamfer 660 applies a bevel feature to edges of a part. A
dialog allows configuration of required entities (such as edges or
faces) and dimensions (such as width for the chamfer). An optional
tangent propagation may extend the selection along surrounding
edges.
[0248] Draft 662 applies a taper to one or more selected faces in
order to, for example, facilitate pulling a part from a mold. A
dialog allows configuration of required entities (face of a part to
act as a neutral plane), dimensions (degree of draft), and
direction. An optional tangent propagation allows applying the
draft to all tangent faces.
[0249] Shell 664 creates a thin-shelled part from a solid part by
removing one or more faces and thickening the rest. A dialog allows
configuration of required entities (one of more faces of a part to
remove), and dimensions (thickness for remaining walls after
removing the selected faces and hollowing out the rest of the
part). An additional option allows selecting whether to create the
shell wall by using the part face as the inside of the shell or the
outside of the shell.
[0250] Pattern 666 allows replication of selected parts or faces.
Linear patterns replicate in a row or grid, and circular patterns
replicate around an axis. A dialog allows configuration of required
entities (one or more parts or faces to replicate, and edge or face
along or around which to replicate), dimensions (distance or
degrees between repetitions and numbers of repetitions), and
direction.
[0251] Mirror 668 allows mirroring one or more selected parts about
a plane or planar face.
[0252] A dialog allows selection of the parts to mirror and the
plane or planar face. The created mirror parts are new parts
independent of the original parts being mirrored.
[0253] Boolean 670 allows merging, differencing, or intersecting
parts. A dialog allows configuration of required entities (parts)
and operation. Union merges parts together, subtract spatially
differences parts, and intersect removes material except where
selected parts intersect. With the subtract option, an additional
choice (keep) enables keeping the subtracted parts, which is useful
when creating fitted parts.
[0254] Split 672 enables splitting an existing part into new parts.
A dialog allows selection of the part to split and a plane or
surface along which to split the part.
[0255] Transform 674 allows moving a part. A dialog allows
selecting the part, type of move related entities or dimensions,
and optionally retaining a separate copy of the part at the
original location. Type of move may be by entity (moving based on
another edge), by distance, by specific axis values (in x, y, z
coordinates), or rotation about a selected axis.
[0256] Copy allows duplicating a part, with the duplicate being a
new part independent of the original.
[0257] Delete 676 allows deletion of one or more parts. Once a part
is deleted, it is removed from the parts list.
[0258] If parts are imported without any parametric history, some
additional options to directly modify geometries can be useful.
Modify fillet 678 allows altering or removing existing fillets.
Delete face 680, move face 682, and replace face 684 allow
modifying faces of a geometric part.
[0259] Plane 686 creates a construction plane, useful for orienting
parts or creating new sketches. It can be based on any part, face,
orientation, point, or line combination sufficient to define a
plane.
[0260] Helix 688 uses a conical or cylindrical face to create a
helix. A dialog allows configuration of entities (base conical or
cylindrical face), dimensions (revolutions or helical pitch), and
direction.
[0261] Rollback Bar
[0262] The model displayed in the graphics area is visualized up to
the position of the Rollback bar 1230 in the Feature list. Dragging
the Rollback bar to any position in the list visualizes the model
at that point and allows inserting new features at that point in
the parametric history. Because the feature list is a sequential
ordering of features which, when applied in order, creates the
current model, dragging the rollback bar to a set position allows
regeneration of the model up to the point of the rollback bar.
Features below the rollback bar remain listed but not applied as
part of the currently displayed model.
[0263] Feature List Editing
[0264] The Feature list supports parametric history editing
operations such as reordering features, deleting features, renaming
features, and suppressing or unsuppressing features. It also allows
easy access to manipulating the display by hiding and showing
parts, sketches and construction geometry and by changing graphical
attributes such as color and opacity.
[0265] Mate Connectors
[0266] Mate connectors are local coordinate system entities located
on or between parts and used within a mate to locate and orient
part instances with respect to each other. Two part instances are
positioned in an assembly by a Mate. The positioning is done by
aligning a Mate connector defined on one instance with a Mate
connector defined on the other instance. These location of these
connectors may be points created when sketching or automatically
generated inference points. The orientation of these connectors may
be automatically inferenced, for example aligned with the
coordinate system of a planar face or axis of a cylinder, or
manually positioned. While manipulating a part viewed in the user
interface, different inference points display based on the view and
area of interest (such as mouse location). User interface controls
(such as pressing a shift key) may prevent or change which
inference points are displayed. Each face and edge of a part has
default inference points at the centroid, midpoints, and corners
(vertices). For cylindrical faces, inference points are on the axis
of the cylinder and partial cylindrical face.
[0267] A dialog allows proper configuration when creating mate
connectors. Mate connectors may be created on a part, or midway
between two entities. A point is input (selected) to the dialog as
part of the mate connector configuration. Further configuration
options include alignment (allowing orientation change along a
primary and/or secondary axis), movement (move the created
connector a specified distance), and rotate (rotate the connector a
specified number of degrees). Once created, mate connectors are
listed in the Feature list, through which they may be selected for
further modification or deletion.
[0268] A Mate connector can be created in both the Assembly and the
Part Studio. Creating a Mate connector 690 in the Part Studio
allows referencing sketch entities, which are available in the Part
Studio but not aspects of parts available to assemblies. This
allows more possible positions to define a Mate connector within a
Part Studio than in an Assembly. Additionally, a mate connector
defined in a Part Studio is available for reuse on every instance
of that part in every assembly in which it is instanced. When
creating a Mate connector in the Part Studio, there is an option in
the Mate connector dialog for identifying an Owner Part. This can
be particularly beneficial when multiple parts exist within the
same Part Studio.
[0269] Once created, users can hide or show Mate connectors in both
Part Studios and Assemblies. This can be done through context menus
available in the Feature list, and set individually or across all
mate connectors.
[0270] Assembly
[0271] The assembly tab is used to define the structure and
behavior of an Assembly. Each Assembly has its own Feature list
that contains instances (of parts and sub-assemblies), Mates, and
Mate Connectors. An instance within an assembly is a reference to
either a part defined in a Part Studio, or to a sub-assembly
defined in another Assembly tab. Mates are used to position
instances and to define how they move. Unlike traditional CAD
systems, which typically use low-level assembly constraints to mate
assembly entities (and, as a result, positioning two instances
usually requires two or three of such constraints), Mates are
high-level entities. There is only one Mate between any two
instances, and the movement (degrees of freedom) between those two
instances is embedded in the Mate. For example, a single Mate can
define a pin slot relationship (or any other type of relationship
between two instances).
[0272] Referring also to FIG. 18, the Assembly tab 620 is used to
define and/or modify a hierarchical structure of part and
sub-assembly instances which combine into an Assembly. It is also
where users define how those instances can move. More than one
Assembly tab can exist in a Project, and one assembly can instance
one or more other assemblies (as sub-assemblies) and/or instance
one or more parts. The basic steps to creating assemblies involve
inserting instances of parts and sub-assemblies, creating mate
connectors (where the instances connect), and creating mates (how
the instances connect).
[0273] An insert dialog allows selecting parts and sub-assemblies
for inclusion in an assembly. This allows selection of a specific
part from a part studio, all parts in a part studio, or an assembly
from a different assembly tab. Selection may be through any
standard user interface selection technology, such as a search
field for named search, or selection from an automatically
populated list. An instance of the selection is then inserted into
the active assembly tab. User interface interaction with the
graphics area may position the inserted instance.
[0274] Once an instance is inserted into an Assembly, a user can
move the instance through user interface controls. For example,
click (or select) and movement may drag the instance (free drag).
Another user interface control which may allow moving and
repositioning instances around the graphics area, and for movement
between instances, is a triad manipulator, which may be activated
after selecting an instance to move. With the triad manipulator, a
user may reposition the manipulator itself, move the instance along
an axis or within the plane, or rotate the instance around the X,
Y, or Z axis. When repositioning the manipulator, users can snap it
to other entities in the Assembly to redefine the entity's position
and orientation.
[0275] An instance which is not mated and not fixed will move
exactly as a user specifies. An instance which is mated will move
as directed within its degrees of freedom. Mates define movement
between instances of parts and/or sub-assemblies. Each mate
requires two instances, aligned through a mate connector on each,
and definition of degrees of freedom (movement) allowed. Any two
instances which move in constraint with each other have a single
mate to define such movement, and only a single mate is required to
define movement between those two instances.
[0276] When creating a mate, two instances are aligned based on a
mate connector of each. This may result in incorrect orientation of
one (or both) instances. A dialog for the mate may allow
configuration of orientation, such as flipping a primary axis
orientation or adjusting a secondary axis orientation in ninety
degree increments. The mate may also be configured for a specific
type of mating, which defines movement behavior (degrees of freedom
within a standard X, Y, Z three-dimensional system). Fastened mates
1800 remove all degrees of freedom. Revolute mates 1810 allow
rotational movement about a single axis. Slider mates 1820 allow
translational movement about a single axis. Planar mates 1830 allow
translational movement along two axis, and rotational movement
along the third axis. Cylindrical mates 1840 allow translational
and rotational movement along one axis. Pin slot mates 1850 allow
rotational movement about one axis and translational movement along
another axis. Ball mates 1860 allow rotational movement about all
three axis. Positioning of instances is the same for all mate types
(dependent on alignment of mate connectors), and the type of mating
may be altered after creation to change the allowed movement
between instances.
[0277] Mate connectors may be created as an aspect of part creation
within a part studio, or created within the assembly as a connector
on an instance. Creating mate connectors 1870 within the assembly
tab functions the same as creating the mate connector within a part
studio, but is more restrictive when created within the assembly
tab (cannot access underlying sketch entities for additional mate
connector points, and will only be created for the instance within
the assembly rather than available for every instance of a
part).
[0278] In addition to mates with mate connectors, grouping 1880 is
possible to fix relative positioning between instances. A dialog
allows selection of multiple instances to fix as a group. Once
fixed, movement of any instance within the group moves the entire
group, keeping the relative positioning fixed. To move an
individual instance within a group, a suppress option suppresses
the entire group (allowing all instances to move independently), or
a specific instance may be removed from the group (making that one
instance independent but retaining fixed relative positioning
between the other group members). When inserting instances of all
parts from a part studio, they may be inserted as a group to
automatically retain relative positioning as designed within the
part studio. Adding a subassembly instance to a group makes the
whole subassembly effectively rigid.
[0279] The assembly tab also contains an assembly feature list
1890, listing the instances, mates, groups, and mate connectors of
the assembly. A user may select any individual list item in the
feature list for modification or editing configuration. If the same
part or sub-assembly is inserted multiple times into an assembly,
the multiple instances are numbered within the assembly tab for
user identification and individual control. Additional assembly
feature list controls include hiding or showing any list entry,
suppressing or unsuppressing any mate or instance, or "fixing" or
"unfixing" an instance to prevent or allow movement of that
instance within the assembly graphics area. When features are
hidden, they are simply removed from the visual display but still
part of the assembly. This can be highly useful in crowded or
complicated models. When mates or instances are suppressed, the
assembly is regenerated and displayed without the suppressed mates
or instances. This can be highly useful to compare with a specific
removal before permanently deleting it from the model.
[0280] Measuring Tools
[0281] Within both part studios and assemblies, tools exist to
measure dimensions or mass properties. Referring also to FIG. 19,
after activating the measure tool, information about selected
entities dimensions 1900 is displayed by the user interface. By
selecting displayed measurement information, the measurement may
also be visualized within the graphics area, such as showing
minimum distances between entities as bold dotted lines, changes in
various dimensions shown in red, green, or blue, and angles shown
as thin dotted lines. Referring also to FIG. 20, after activating
the mass properties tool, selected entities are cumulatively added.
A dialog allows deleting (or adding) selected entities from the
mass properties calculation, and selection of which mass property
to calculate. Options to calculate include volume, surface area,
center of mass, or moment of inertia (with respect to a common
centroid of the selected entities, and assuming density of 1 in
units used for the project or using density and other properties of
material specifications associated with each of the entities), of
the selected entities. For any intersecting parts, properties are
calculated for each individual part and then added together.
Calculations of properties are done by the 3DGCS and returned to
the client for display in a mass properties dialog 2000.
[0282] History
[0283] While a user works within a project workspace, the DPS
automatically records the state of each tab (Part Studio,
Assemblies, etc) at each persisted change made to any tab for the
workspace. This persistent transaction history is listed in a
History of the project. At any time the user can restore all tabs
in the currently active workspace to any particular prior point in
its History.
[0284] Every persisted change to a tab in a workspace is recorded
in the project's History. Referring also to FIG. 21, records are
listed for all tabs in the currently active workspace. The system
captures the state of every tab in a workspace every time an edit
is completed (by all users working in that workspace). This means
that for every project there is an historical record of all states
in which it has existed. As a result, users never have to worry
about constantly saving their work. Users can always make changes
with confidence that if the changes don't work out, they can find
and restore any earlier state. In addition, users can use versions,
branching, and merging to explore multiple design variations in
parallel, either on their own or with other users. Restoring a
project to a previous modification state can be used to reverse a
design merge made through the Version Manager. The creation of
workspaces and the merging of workspaces is also recorded in the
persistent transaction history.
[0285] The description of a record in the History list 2100 may be
in a format such as "Tab-name::Action:Feature-name." Each entry in
the History list includes displayable information (either by
default or via user interface actions such as on-hover) to see who
made the modification and when. Selecting an entry in the History
list visualizes the project at that History point (including the
feature listed). After visualizing at a particular History point, a
Restore option is available to restore the workspace to that
particular point. Such Restore action also becomes a record in the
project's persistent transaction history.
[0286] A project may have many workspaces; one for each branch. At
any point in time, a user can save a state of a workspace as
immutable, thereby creating a version. A version is a snapshot of a
project at a particular point in time. The geometric data (and the
accompanying data like Part names, etc.) of that version is
unchangeable. This is a very valuable and unique feature. There are
many references between parts and assemblies in CAD. In the prior
art, these references cross stored named files and are "live". This
meant it was very easy to inadvertently change one file and
unknowingly modify others. In many cases it is very difficult to
know if such a follow-on change occurred and there is often no
reasonable way to change one part without changing the referencing
part. Such changes often impacted additional files recursively as
well; a second part forcing a third part to change, and so on. This
is a very serious and costly flaw in the prior art. In the
disclosed system, references between projects are always to
versions, and versions are immutable. Changes are made to a new
workspace above the immutable version. When the workspace is
versioned, the user receives a notification, and by taking a
specific action, can control whether the to update the referencing
project or not.
[0287] Users can, however, change the meta data of a version. Users
can create many versions of a project. Managing the workflow around
versions and workspaces is performed through the Version
Manager.
[0288] Version Manager
[0289] Referring also to FIG. 22, the system provides a graphical
representation of versions 2200 and workspaces 2210 in the Version
Manager. As one or more users work in a project, each user can at
any time mark a new version of the workspace. Users can also create
a new workspace (branch) from a version. Note that marking a
version and creating a new workspace are separate actions, as
versions are read-only.
[0290] When viewing various versions, the name 2220 of the version
appears beside the project title, and below that is a link to
return to the workspace. Each version of a project is represented
by a solid dot on the graph, and each workspace is indicated by an
open circle. Users can create a new workspace from any version by
selecting Branch from a user interface menu. Opposite to feature
lists, the version graph grows from the bottom up with the first
version of the project at the bottom of the graph.
[0291] Version actions include Open (open and switch to the
graphics area for the selected version in view only mode), Open in
new browser tab (open the selected version in a new browser tab in
view only mode), Branch to create workspace (create a new branch
and workspace from the selected version), and Properties (create or
edit meta data about the selected version). Workspace actions
include Open (switch to and open the graphics area for the selected
workspace), Open in new browser tab (open the selected workspace in
a new browser tab), History (view the persistent transaction
history records for the selected workspace), Properties (create or
edit meta data for the selected workspace), and Delete (delete the
selected workspace; note that users cannot delete the last
remaining workspace--to do so requires deleting the entire
project).
[0292] Real world use cases illustrate examples which leverage the
Version Manager functionality. When developing multiple variants
independently, or when seeking regulatory approval in any number of
different markets, users may use the Version Manager for a number
of largely independent development efforts all contained in a
single project. Each branch may hold changes specific to that
market and the various parts and projects would reach release and
regulatory approval states at different times. Another example use
is when branching an initial design to evaluate a number of
competing concepts with only one being chosen to develop to a
release state. Another example use is when a large group of
designers want to work independently on a number of ideas or
changes that may or may not make it into the final design.
[0293] Sharing
[0294] The system enables simultaneous editing between multiple
users. Referring also to FIG. 23, users can share a project with
whomever they want by entering the email address 2300 of someone to
share it. Upon sharing, the DPS, AMBS, and AMCS generate an email
notification about the shared project. If the share recipient is a
registered user, the shared project is made available within that
account. If the share recipient is not yet registered, the emailed
notification includes information about creating an account in
order to access the shared project. Different share permissions are
available, including view (read-only), edit (read and edit), and
edit & share (read, edit, and extend permissions to other
users), and may be set when sharing or changed at any later
point.
[0295] The user can choose to disallow any operations in the system
that would allow the user to make copies of or download the data in
the document. This could be available at any permission level. In
other words, the sharee could be allowed to work within the
document in a read-only manner or to edit the document. The
sharee's access can also be removed whenever the user desires.
These capabilities give the user greater control over who can
access his data, how long they can access it, and how they can
access it using the system. In prior CAD systems, data could only
be shared by sending the sharee a copy of the file. Once the file
was copied, the initial user no longer had any visibility or
control over who accessed that file and who they distributed it
too.
[0296] Projects allow both simultaneous editing (many users working
together in one workspace of a project simultaneously) and branched
editing (many users working independently but in parallel
workspaces of a project with the ability to compare and merge
later).
[0297] Referring also to FIG. 24, users can work in the same
project workspace at the same time, referred to as Simultaneous
Editing. The creator of the project must Share it with the other
users before they can collaborate. Within shared projects, social
cues indicate what is being edited. Social cues may be graphical
indicators, such as a colored box with letter indication an initial
of a specific user's name, placed to identify who is viewing a
project, which tab they are currently viewing, and any feature list
items actively being viewed or edited. At the top is indication
2400 of who is actively viewing or editing the project. At the
bottom, social cues 2410 in a tab indicate who is actively viewing
or editing a file. At the side, social cues 2420 within the feature
list or assembly feature list indicate users actively editing
specific feature or assembly entities.
[0298] Branching
[0299] A user always works in an active workspace. A project may
have many workspaces, which under most circumstances do not
interact with each other. Any changes a user makes within an active
workspace are immediately reflected in that workspace and not in
any others; any collaborators in the same workspace are immediately
updated.
[0300] A user may bookmark a particular state of a project
workspace for future reference by saving a version, a permanent and
immutable state of the project. A user may branch by creating a new
workspace at a given version. The initial state of the project in
the new workspace is identical to that of the version. Workspaces
and versions form a directed acyclic graph with a "parent"
relationship; the first "parent" of a workspace being the version
it was branched from, and the parent of a version being the parent
version of the workspace it was saved from. As described so far the
graph is actually a tree.
[0301] Merging
[0302] Project branches (separate workspaces within the same
project) may be merged together. A basic merging scenario involves
one branch which contains all newer changes from another branch,
and the user merging from that branch into the one to update. A
more complex merging scenario involves a main workspace, or master
design, and multiple branched workspaces for developing changes,
with merging intended to incorporate some changes across multiple
branches into the main workspace.
[0303] To handle all merging scenarios within a CAD system, the
parametric history of each branch is compared as a linear list of
features, with corresponding graphical representations. This is
presented to a user to compare the two lists side by side textually
in a similar manner to software comparison tools. The user may
select or highlight any particular feature step in the parametric
history, which optionally may display updated side-by-side or
merged 3D graphical representations of each workspace at that
feature step. This means that the user can both textually and
visually understand the differences between the two models at that
feature step. In addition to the text and graphical displays,
dialogs for the selected feature for each branch may display with
values from each workspace, and differences may be identified
within the user interface such as through highlighting.
[0304] From the selected features, the user may incrementally push
(merge) a change from one workspace into the other. The servers
then regenerate the merged workspace incorporating the change, and
the merge itself is tracked as a new change within the persistent
transaction history of the workspace.
[0305] In this regard the system is doing much more than the
similar compare and diff tools currently do in traditional software
development. The CAD user sees three representations of the data
(feature list, feature dialog, and graphical 3D model) of each
different workspace of the project. The CAD user sees the actual
regeneration results side by side at that step. In software, the
analogy would be a tool that not only compared the text
side-by-side, but also compiled and ran the program--and showed the
different running programs in results.
[0306] With merging different branches, it is assumed that the
definition of the shapes of parts occurs in a part modeling
environment with a parametric history (Part Studio), and the
definition of the assembly occurs in a separate assembly modeling
environment (Assembly). The merging discussed above is focused on
the part modeling environment.
[0307] In the assembly environment, as described above with respect
to parts, any assembly can be deconstructed into a linear set of
operations that construct the assembly. For example, an assembly
can be deconstructed into a set of instance insertion steps,
followed by a set of positioning steps (that position the instances
in 3d space), followed by a set of constraint definition steps.
There are other deconstructions that would work just as well--this
is just one example.
[0308] Through deconstruction the assembly can be represented as a
set of steps. These steps will generally be different and in a
different order than the steps (feature list) the user actually
used to create the assembly (unlike in the parametric part
history). Nevertheless, they are easily understood by the user
since they correspond to interactive tools that the CAD user uses
to create assemblies.
[0309] Using these steps, and the user interface (such as dialogs)
for the interactive tools, the assembly steps can be presented to
the user in the same manner as the part feature steps were. The
visual compare and incremental merge tools can then be used to
compare and edit the assemblies.
[0310] Text-Feature-Editing
[0311] The feature selection with graphical correspondence
discussed within merging exists during normal editing within a
project. Making a selection within the graphics area may highlight
or activate corresponding entries in the feature, and selecting
within the feature list may highlight corresponding entities within
the graphics area. Referring also to FIG. 25, this may be extended
even further, and include a third representation as a code or
script. The underlying implementation may maintain an abstract
syntax tree (AST) 2500 of an object-oriented representation of a
program corresponding to the CAD model, including the parametric
feature list. Each entry in the feature list, with feature
parameters and model definition components, corresponds to one or
more subtrees of the AST. This correspondence allows
cross-highlighting between the feature list 2510, a textual
representation of the program 2500, and graphical display 2520. An
optional overlay may display the textual representation, and enable
three different, but corresponding, editing options. Edits to the
feature tree, graphical area, or textual representation may be
correspondingly updated across all three editing options.
Similarly, when a user moves user interface control (e.g., the
mouse pointer) over a feature or another portion of the GUI
representation, the corresponding portion of the program text is
highlighted.
[0312] Reference Manager
[0313] When working with a CAD design, many geometric elements may
be created based on other geometries. The geometry and relationship
data are tracked as references between objects. When working within
a single parametric history, making any change can be visualized
from the point of change all the way to the final design (with all
later features also applied). When working with multiple parametric
histories, the problem of any single change becomes more complex.
With multiple part files and assemblies, making a change within one
parametric history can trigger changes (and errors) within
others.
[0314] When the related objects are generated by distinctly
separate parametric histories in the context of an assembly, they
are referred to as in-context references. When the context changes,
by either changing the surrounding objects or removing an object
from the context altogether for reuse elsewhere, references may
become invalid and subsequently difficult to manage. A Reference
Manager maintains a local context to keep these references in a
valid, solvable state. Additionally, the Reference Manager provides
a notification mechanism to inform users when in-context references
are out of sync, and provides options for maintaining desired
design intent.
[0315] The Reference Manager can be viewed as a tool to help a user
through unresolved references by notification when unresolved
conditions exist, flagging affected items, and offer resolution
options. The Reference Manager is preferably a module operated by
the CEWS. As a separate module, the Reference Manager may be
operated as a separate module, and also integrated into other CAD
systems (either as a separate module or directly as part of a main
CAD software program). Thus, the Reference Manager may operate for
multiple parametric histories within a project of the system, for
references within a project which instance parametric histories
(parts or sub-assemblies) and/or other parameter values, text, or
other non-geometric data outside of the project's compound
document, or for other CAD systems which use different storage
techniques for parts and assemblies used instanced in a CAD design.
Changing the geometry of any individual part can impact the
assembly containing the part being changed, as well as any other
assembly containing the part. The change can have an expanding
greater impact if geometries of other parts are also changed to
accommodate the change to the initial part. Changes may also impact
other part features if they depend on the geometry of the part
being changed. To ensure stable design while making part changes,
the Reference Manager maintains copies of parts pre-change,
inspects and tracks references of an assembly, redefines references
when possible based on user changes, identifies and provides
notification for out-of-sync conditions, and provides user options
on how to handle out-of-sync conditions.
[0316] In-context references may be created in multiple different
ways. In-context references may be created by sketches within the
one parametric history referencing instances of parts created
within a separate parametric history. Referring also to FIGS. 26A
& 26B, one example of this is using one or more edges 2600 of
one or more parts 2610 to define one or more the edges 2620 of
another part 2630. As another example, a sketch may be on a plane
generated from another parametric history. Referring also to FIG.
27, in-context references may also be created by features, such as
defining end conditions for one part which depend on other parts
(as shown, the cylinder 2700 bottom 2710 is defined by the top of
the rectangular block 2720), defining one part's interaction with
another part (such as to added to, subtracted from, or intersected
with), specifying a face to split a body with, or defining a
reference axis for rotation or reference edge for a pattern.
References may also be created from an equations and variant table,
which may contain expressions determining geometry such as a length
or a line, or other dimensional value. All of the above refer to
creation methods where items from one parametric history use items
generated by a separate parametric history.
[0317] When an in-context reference is created, the Reference
Manager creates a back-up geometry. The back-up geometry is a copy
of a portion of the referenced object as it was at the time of
reference creation. By maintaining a copy of the original
referenced geometry, the system can treat the resultant object as
independent with no dependency on the parent if desired. Instead of
requiring the parent (or target) object to always be present and
viable, this maintains completely resolved and correct objects
independent of changes made in other parametric histories. Changes
made in other parametric histories can be applied, but are not
forced to be applied due to the backup geometry.
[0318] When geometry or parameters of a part is changed, the
Reference Manager examines references to determine if any problems
have been introduced. Problems include assemblies or sub-assemblies
which are cannot regenerate after the change, due to unsolvable
conditions or conditions that results in multiple different
possible solutions. Referring also to FIG. 28, if an out-of-sync
condition exists due to a change in a separate parametric history
altering a part used, notification 2800 is raised for the
condition. Notification may be in the form of a flashed message or
alert within the user interface, graphical indication on at tab
having out-of-sync objects, textual identification of the number of
out-of-sync objects, and graphical indication within the feature
list of any features or parts which are out-of-sync.
[0319] A user may select any of the notifications or corresponding
graphics to address the out-of-sync conditions. From the selection,
and referring also to FIG. 29, the user may sync 2810 or update
with the changed (new) geometry. This selection causes the
reference manager to replace the backup geometry with the changed
geometry, and solve (through the 3DGCS) the new result