U.S. patent application number 13/527184 was filed with the patent office on 2012-10-11 for geospatial data system for selectively retrieving and displaying geospatial texture data based upon user-selected point-of-view and related methods.
This patent application is currently assigned to HARRIS CORPORATION. Invention is credited to FRANK HOWARD EVANS, III, MARK ALLEN INGERSOLL.
Application Number | 20120256919 13/527184 |
Document ID | / |
Family ID | 39967437 |
Filed Date | 2012-10-11 |
United States Patent
Application |
20120256919 |
Kind Code |
A1 |
INGERSOLL; MARK ALLEN ; et
al. |
October 11, 2012 |
GEOSPATIAL DATA SYSTEM FOR SELECTIVELY RETRIEVING AND DISPLAYING
GEOSPATIAL TEXTURE DATA BASED UPON USER-SELECTED POINT-OF-VIEW AND
RELATED METHODS
Abstract
A geospatial data system may include at least one geospatial
database containing three-dimensional (3D) geospatial structure
data and geospatial texture data associated with the geospatial 3D
structure data. At least one geospatial data access device may also
be included and comprise a display and a processor cooperating
therewith for communicating remotely with the at least one
geospatial database to retrieve and display a scene on the display
based upon the 3D structure data and the geospatial texture data
associated therewith. The geospatial data access device(s) may
further comprise at least one user input device cooperating with
the processor for permitting user selection of a point-of-view
(POV) within the scene on the display with the POV determining
revealed portions and obscured portions of 3D geospatial structures
within the scene on the display. The processor may selectively
retrieve geospatial texture data based upon the revealed portions
and not the obscured portions.
Inventors: |
INGERSOLL; MARK ALLEN; (PALM
BAY, FL) ; EVANS, III; FRANK HOWARD; (MELBOURNE,
FL) |
Assignee: |
HARRIS CORPORATION
MELBOURNE
FL
|
Family ID: |
39967437 |
Appl. No.: |
13/527184 |
Filed: |
June 19, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11847510 |
Aug 30, 2007 |
8212807 |
|
|
13527184 |
|
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Current U.S.
Class: |
345/419 |
Current CPC
Class: |
G06T 15/04 20130101;
G06T 19/00 20130101; G06T 15/20 20130101; G06T 17/05 20130101 |
Class at
Publication: |
345/419 |
International
Class: |
G06T 15/00 20110101
G06T015/00 |
Claims
1. A geospatial data system comprising: at least one geospatial
database containing three-dimensional (3D) geospatial structure
data, and containing geospatial texture data associated with the
geospatial 3D structure data; and at least one geospatial data
access device comprising a display and a processor cooperating
therewith for communicating remotely with said at least one
geospatial database to retrieve and display a scene on said display
based upon the 3D structure data and the geospatial texture data
associated therewith; said at least one geospatial data access
device further comprising at least one user input device
cooperating with said processor for permitting user selection of a
point-of-view (POV) within the scene on said display with the POV
determining revealed portions and obscured portions of 3D
geospatial structures within the scene on said display, said
processor selectively retrieving geospatial texture data based upon
the revealed portions and not the obscured portions of the 3D
geospatial structures within the scene on said display.
2. The geospatial data system of claim 1 wherein the geospatial
texture data contained in said at least one geospatial database is
retrievable in successive additive layers of resolution; and
wherein said processor retrieves and displays the geospatial
texture data in successive additive layers of resolution in the
scene on said display.
3. The geospatial data system of claim 1 wherein said processor
prioritizes retrieval and display of successive additive layers of
resolution of associated geospatial texture data to different 3D
geospatial structures within the scene on said display.
4. The geospatial data system of claim 3 wherein said processor
prioritizes based upon relative distances of the 3D geospatial
structures within the scene on said display.
5. The geospatial data system of claim 3 wherein said processor
prioritizes based upon different relative areas of the 3D
geospatial structures within the scene on said display.
6. The geospatial data system of claim 1 further comprising a
communications channel coupling said at least one geospatial
database and said geospatial data access device; and wherein said
communications channel has a capacity insufficient to carry within
a predetermined time all of the associated geospatial texture data
for the 3D geospatial structures within the scene on said
display.
7. The geospatial data system of claim 6 wherein said
communications channel comprises the Internet.
8. The geospatial data system of claim 1 wherein said at least one
geospatial database and said at least one geospatial data access
device communicate using a streaming wavelet-based imagery
compression protocol.
9. The geospatial data system of claim 8 wherein the streaming
wavelet-based imagery compression protocol comprises the JPEG 2000
Interactive Protocol.
10. A geospatial data access device for accessing at least one
geospatial database containing three-dimensional (3D) geospatial
structure data, and also containing geospatial texture data
associated with the geospatial 3D structure data, the geospatial
data access device comprising: a display; a processor cooperating
with said display for communicating remotely with the at least one
geospatial database to retrieve and display a scene on said display
based upon the 3D structure data and the geospatial texture data
associated therewith; and at least one user input device
cooperating with said processor for permitting user selection of a
point-of-view (POV) within the scene on said display with the POV
determining revealed portions and obscured portions of 3D
geospatial structures within the scene on said display; said
processor selectively retrieving geospatial texture data based upon
the revealed portions and not the obscured portions of the 3D
geospatial structures within the scene on said display.
11. The geospatial data access device of claim 10 wherein the
geospatial texture data contained in the at least one geospatial
database is retrievable in successive additive layers of
resolution; and wherein said processor retrieves and displays the
geospatial texture data in successive additive layers of resolution
in the scene on said display.
12. The geospatial data access device of claim 10 wherein said
processor prioritizes retrieval and display of successive additive
layers of resolution of associated geospatial texture data to
different 3D geospatial structures within the scene on said
display.
13. The geospatial data access device of claim 12 wherein said
processor prioritizes based upon relative distances of the 3D
geospatial structures within the scene on said display.
14. The geospatial data access device of claim 12 wherein said
processor prioritizes based upon different relative areas of the 3D
geospatial structures within the scene on said display.
15. A geospatial data access method comprising: storing
three-dimensional (3D) geospatial structure data and geospatial
texture data associated with the geospatial 3D structure data in at
least one geospatial database; remotely retrieving the 3D structure
data and the geospatial texture data associated therewith from the
at least one geospatial database; and displaying a scene on a
display based upon the retrieved 3D structure data and the
geospatial texture data associated therewith and also based upon a
user selection of a point-of-view (POV) within the scene on the
display with the POV determining revealed portions and obscured
portions of 3D geospatial structures within the scene on the
display; wherein remotely retrieving further comprises selectively
retrieving geospatial texture data based upon the revealed portions
and not the obscured portions of the 3D geospatial structures
within the scene on the display.
16. The method of claim 15 wherein the geospatial texture data
contained in the at least one geospatial database is retrievable in
successive additive layers of resolution; and wherein remotely
retrieving and displaying comprise remotely retrieving and
displaying the geospatial texture data in successive additive
layers of resolution in the scene on the display.
17. The method of claim 15 further comprising prioritizing
retrieval and display of successive additive layers of resolution
of associated geospatial texture data to different 3D geospatial
structures within the scene on the display.
18. The method of claim 17 wherein prioritizing comprises
prioritizing based upon relative distances of the 3D geospatial
structures within the scene on the display.
19. The method of claim 17 wherein prioritizing comprises
prioritizing based upon different relative areas of the 3D
geospatial structures within the scene on the display.
20. A computer-readable medium having computer-executable
instructions for causing a computer to perform steps comprising:
remotely retrieving three-dimensional (3D) structure data and
geospatial texture data associated therewith from at least one
geospatial database; and displaying a scene on a display based upon
the retrieved 3D structure data and the geospatial texture data
associated therewith and also based upon a user selection of a
point-of-view (POV) within the scene on the display with the POV
determining revealed portions and obscured portions of 3D
geospatial structures within the scene on the display; wherein
remotely retrieving further comprises selectively retrieving
geospatial texture data based upon the revealed portions and not
the obscured portions of the 3D geospatial structures within the
scene on the display.
21. The computer-readable medium of claim 20 wherein the geospatial
texture data contained in the at least one geospatial database is
retrievable in successive additive layers of resolution; and
wherein remotely retrieving and displaying comprise remotely
retrieving and displaying the geospatial texture data in successive
additive layers of resolution in the scene on the display.
22. The computer-readable medium of claim 20 further comprising
prioritizing retrieval and display of successive additive layers of
resolution of associated geospatial texture data to different 3D
geospatial structures within the scene on the display.
23. The computer-readable medium of claim 22 wherein prioritizing
comprises prioritizing based upon relative distances of the 3D
geospatial structures within the scene on the display.
24. The computer-readable medium of claim 22 wherein prioritizing
comprises prioritizing based upon different relative areas of the
3D geospatial structures within the scene on the display.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to the field of modeling
systems, and, more particularly, to geospatial modeling systems and
related methods.
BACKGROUND OF THE INVENTION
[0002] Topographical models of geographical areas may be used for
many applications. For example, topographical models may be used in
flight simulators and for planning military missions. Furthermore,
topographical models of man-made structures (e.g., cities) may be
extremely helpful in applications such as cellular antenna
placement, urban planning, disaster preparedness and analysis, and
mapping, for example.
[0003] Various types and methods for making topographical models
are presently being used. One common topographical model is the
digital elevation map (DEM). A DEM is a sampled matrix
representation of a geographical area which may be generated in an
automated fashion by a computer. In a DEM, coordinate points are
made to correspond with a height value. DEMs are typically used for
modeling terrain where the transitions between different elevations
(e.g., valleys, mountains, etc.) are generally smooth from one to a
next. That is, DEMs typically model terrain as a plurality of
curved surfaces and any discontinuities therebetween are thus
"smoothed" over. Thus, in a typical DEM no distinct objects are
present on the terrain.
[0004] One particularly advantageous 3D site modeling product is
RealSite.RTM. from the present Assignee Harris Corp. RealSite.RTM.
may be used to register overlapping images of a geographical area
of interest, and extract high resolution DEMs using stereo and
nadir view techniques. RealSite.RTM. provides a semi-automated
process for making three-dimensional (3D) topographical models of
geographical areas, including cities, which have accurate textures
and structure boundaries. Moreover, RealSite.RTM. models are
geospatially accurate. That is, the location of any given point
within the model corresponds to an actual location in the
geographical area with very high accuracy. The data used to
generate RealSite.RTM. models may include aerial and satellite
photography, electro-optical, infrared, and light detection and
ranging (LIDAR).
[0005] Another advantageous approach for generating 3D site models
is set forth in U.S. Pat. No. 6,654,690 to Rahmes et al., which is
also assigned to the present Assignee and is hereby incorporated
herein in its entirety by reference. This patent discloses an
automated method for making a topographical model of an area
including terrain and buildings thereon based upon randomly spaced
data of elevation versus position. The method includes processing
the randomly spaced data to generate gridded data of elevation
versus position conforming to a predetermined position grid,
processing the gridded data to distinguish building data from
terrain data, and performing polygon extraction for the building
data to make the topographical model of the area including terrain
and buildings thereon.
[0006] Nonetheless, topographical models are no longer reserved for
advanced modeling systems such as those discussed above. Various
Internet service providers such as Google.TM. and Microsoft.RTM.
are looking to provide access to 3D topographical models over the
Internet that show users how a city or location appears in as much
realism as possible. This may advantageously help increase a user's
awareness of a given area and provide an exploratory environment.
Such companies are striving to provide environments that are easier
to use, more realistic and ultimately more useful. Improving the
user experience involves increasing the quality of the 3D
environment in terms of better terrain, more highly detailed
city/building models, and higher resolution imagery of the terrain
and buildings.
[0007] However, one significant challenge is that, while the
terrain and models are quite small in terms of their geometries or
structure, the imagery and textures used to enhance the basic
models are typically very large. Over a high-speed network, such as
that found within most corporate networks, downloading models and
textures from a local network server is relatively fast and
therefore not particularly problematic. Over the Internet, however,
downloading these quantities of data can be extremely slow and
significantly diminish user experience because of the relatively
limited bandwidth available.
[0008] Currently, several network-enabled 3D viewers exist that
permit users to view models from a network or Internet server.
These viewers include Google.TM. Earth, Microsoft.RTM.
VirtualEarth, and NASA WorldWind. All viewers share the ability to
view untextured building models with some varying degree of
textured terrain. Textured models tend to be very rudimentary.
Microsoft.RTM. VirtualEarth attempts to apply textures over their
models, but the delay can be so long as to become unacceptable to
users.
[0009] Various approaches have been developed for remotely
accessing terrain data. One example is set forth in U.S. Pat. No.
6,496,189 to Yaron et al. This patent discloses a method of
providing data blocks describing three-dimensional terrain to a
renderer. The data blocks belong to a hierarchical structure which
includes blocks at a plurality of different resolution layers. The
method includes receiving from the renderer one or more coordinates
in the terrain along with indication of a respective resolution
layer, providing the renderer with a first data block which
includes data corresponding to the coordinate(s) from a local
memory, and downloading from a remote server one or more additional
data blocks which include data corresponding to the coordinate(s)
if the provided block from the local memory is not at the indicated
resolution layer. Despite the existence of such approaches, further
advancements may be desirable for remotely retrieving and
displaying large amounts of geospatial data.
SUMMARY OF THE INVENTION
[0010] In view of the foregoing background, it is therefore an
object of the present invention to provide a system and related
methods for efficiently retrieving and displaying geospatial
data.
[0011] This and other objects, features, and advantages are
provided by a geospatial data system that may include at least one
geospatial database containing three-dimensional (3D) geospatial
structure data, and also containing geospatial texture data
associated with the geospatial 3D structure data. The system may
further include at least one geospatial data access device, which
may comprise a display and a processor cooperating therewith for
communicating remotely with the at least one geospatial database to
retrieve and display a scene on the display based upon the 3D
structure data and the geospatial texture data associated
therewith. Moreover, the at least one geospatial data access device
may further comprise at least one user input device cooperating
with the processor for permitting user selection of a point-of-view
(POV) within the scene on the display with the POV determining
revealed portions and obscured portions of 3D geospatial structures
within the scene on the display. Further, the processor may
advantageously selectively retrieve geospatial texture data based
upon the revealed portions and not the obscured portions of the 3D
geospatial structures within the scene on the display.
[0012] More particularly, the geospatial texture data contained in
the at least one geospatial database may be retrievable in
successive additive layers of resolution, and the processor may
therefore retrieve and display the geospatial texture data in
successive additive layers of resolution in the scene on the
display. Furthermore, the processor may prioritize retrieval and
display of successive additive layers of resolution of associated
geospatial texture data to different 3D geospatial structures
within the scene on the display. By way of example, the processor
may prioritize based upon relative distances of the 3D geospatial
structures within the scene on the display. Also, the processor may
prioritize based upon different relative areas of the 3D geospatial
structures within the scene on the display.
[0013] The geospatial data system may further comprise a
communications channel coupling the at least one geospatial
database and the geospatial data access device. The communications
channel may have a capacity insufficient to carry within a
predetermined time all of the associated geospatial texture data
for the 3D geospatial structures within the scene on the display.
By way of example, the communications channel may comprise the
Internet. Additionally, the at least one geospatial database and
the at least one geospatial data access device may communicate
using a streaming wavelet-based imagery compression protocol, such
as the JPEG 2000 Interactive Protocol, for example.
[0014] A related geospatial data access method aspect may include
storing 3D geospatial structure data and geospatial texture data
associated with the geospatial 3D structure data in at least one
geospatial database. The method may further include remotely
retrieving the 3D structure data and the geospatial texture data
associated therewith from the at least one geospatial database.
Additionally, a scene is displayed on a display based upon the
retrieved 3D structure data and the geospatial texture data
associated therewith and also based upon a user selection of a
point-of-view (POV) within the scene on the display with the POV
determining revealed portions and obscured portions of 3D
geospatial structures within the scene on the display. In
particular, remotely retrieving may further comprise selectively
retrieving geospatial texture data based upon the revealed portions
and not the obscured portions of the 3D geospatial structures
within the scene on the display.
[0015] A related computer-readable medium is also provided having
computer-executable instructions for causing a computer to perform
steps including remotely retrieving three-dimensional (3D)
structure data and geospatial texture data associated therewith
from at least one geospatial database, and displaying a scene on a
display based upon the retrieved 3D structure data and the
geospatial texture data associated therewith and also based upon a
user selection of a point-of-view (POV) within the scene on the
display. The POV may advantageously determine revealed portions and
obscured portions of 3D geospatial structures within the scene on
the display. Remotely retrieving may further comprise selectively
retrieving geospatial texture data based upon the revealed portions
and not the obscured portions of the 3D geospatial structures
within the scene on the display.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic block diagram of a geospatial data
system in accordance with the invention.
[0017] FIGS. 2 and 3 are schematic block diagrams of the geospatial
data system of FIG. 1 in greater detail for a JPEG 2000
implementation.
[0018] FIG. 4 is a series of geospatial texture images illustrating
progressive texture data rendering of the system of FIG. 1.
[0019] FIGS. 5A-5C are another series of geospatial texture images
also illustrating progressive texture data rendering of the system
of FIG. 1.
[0020] FIG. 6 is a system flow diagram illustrating method aspects
of the invention.
[0021] FIG. 7 is a schematic block diagram of an alternative
embodiment of the system of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings, in which
preferred embodiments of the invention are shown. This invention
may, however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein. Rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. Like numbers refer to like
elements throughout, and prime notation is used to indicate similar
elements in alternate embodiments.
[0023] Referring initially to FIGS. 1-6, a geospatial data system
30 and associated methods are now described. The system 30
illustratively includes one or more geospatial data storage devices
31 containing three-dimensional (3D) geospatial structure data, and
also containing geospatial texture data associated with the
geospatial 3D structure data and being retrievable in successive
additive layers of resolution. As used herein, "structure" data
includes man-made (e.g., buildings, bridges, etc.) data, and the 3D
geospatial structure data may be in the form of a DEM, such as a
tiled triangulated irregular network (T-TIN), for example. The
geospatial texture data may be optical (i.e., image) data, for
example, that is used to overlay or texture the DEM, etc., to make
the image appear more realistic, as will be appreciated by those
skilled in the art. In the example of FIG. 2, the geospatial data
storage device 31 is implemented in an Internet model library
server 39, as will be appreciated by those skilled in the art.
[0024] The system further illustratively includes one or more
geospatial data access devices 32 for remotely accessing the
geospatial data storage device(s) 31, such as via a wide area
network 33, which in the illustrated embodiment is the Internet.
The geospatial access device 32 illustratively includes a display
34 and a processor 35, such as the central processing unit (CPU) of
a personal computer (PC) or Macintosh computer, for example,
although other types of processors (workstations, personal digital
assistant (PDA) devices, laptops, etc., may also be used). In the
example illustrated in FIG. 2, the geospatial access device 32 is
an Internet-enabled device.
[0025] Generally speaking, the processor 35 runs a viewer program
60 that cooperates with the display 34 for communicating remotely
with the geospatial data storage device 31 to retrieve and display
a scene on the display based upon the 3D structure data and the
geospatial texture data associated therewith. As discussed above,
when retrieving high volumes of geospatial texture data over a
relatively limited bandwidth communications channel, such as the
Internet (compared to a local high speed network connection, for
example), this can make rendering of a geospatial scene or model on
the display 34 very cumbersome and frustrating for the user. Stated
alternatively, the communications channel (e.g., the Internet) may
have a capacity insufficient to carry within a predetermined time
(i.e., the time the processor 35 could otherwise render the scene)
all of the associated geospatial texture data for the 3D geospatial
structures within the scene on the display 34.
[0026] Typically, the transfer of 3D geospatial structure data will
be relatively fast due to its smaller file size (e.g., on the order
of kilobytes), and can therefore be substantially immediately sent
and displayed upon request from the geospatial data access device
32. On the other hand, the geospatial texture data can be on the
order of several megabytes or larger, for example, which delays the
rendering of the geometry and the processor 35 otherwise waits
until all data is retrieved to begin the rendering process.
[0027] Rather than compromise the geospatial texture data (and thus
the ultimate image) by reducing the resolution, or using smaller
size synthetic textures that can provide false or misleading
images, the geospatial texture data is advantageously retrieved and
displayed in successive additive layers 36a-36d of resolution
(i.e., it is "streamed" in layers). This may advantageously make
the user experience more interactive as model textures
progressively sharpen as the user navigates through a geospatial
model/scene, as will be appreciated by those skilled in the
art.
[0028] More particularly, within the past several years, a
wavelet-based imagery compression technology known as JPEG 2000 has
been established and standardized that decreases the data required
for a given image. A section of this specification enables imagery
streaming, known as JPEG 2000 Interactive Protocol (JPIP) under
part 9 of the specification, which is hereby incorporated herein in
its entirety by reference. In the satellite imagery markets, this
technique may allow users to effectively browse images that are
several Gigabytes in size over connections as slow as 16
kB/sec.
[0029] Applicants have discovered that if the JPIP technique is
applied to model textures, this effectively enhances the user
experience by reducing the amount of data necessary to texture a
model in varying resolutions. Streaming textures is a different
approach than the current method of downloading full-resolution
textures (or multiple textures of varying resolutions), which takes
advantage of the more efficient and interactive protocol noted
above.
[0030] In accordance with one embodiment, the effective user
experience may include loading of untextured models, followed by
textured models that progressively increase in resolution as the
user approaches buildings or other objects within the scene (i.e.,
changes the point-of-view (POV)). In other embodiments, the viewer
program may use whichever texture is available, and the user might
not ever see an untextured model. For example, if the
client-software requests both the structure and the texture data
and the texture stream arrives first, the user would not see the
untextured model. The viewer program will typically display the
scene from an initial (startup) viewpoint (Block 61), and the user
can change the POV using any suitable user input device, such as
the illustrated keyboard 38, a mouse, joystick, etc. (Block 62).
Objects that are farther away are only rendered using lower
resolutions of the image (known as quality layers within the JPEG
2000 file), at Blocks 63-64 as discussed further below. As the user
moves closer to a structure(s) (i.e., zooms in the POV), the
structure/geometry data therefor is retrieved and displayed (Blocks
65-67), which may initially be without texture (or with only a
first layer of texture). Successive additive layers of texture are
then streamed in to increase the scene or model's appearance and
displayed accordingly, as will be discussed further below. This
technique may advantageously be leveraged over networks of modest
bandwidth and in effect, makes very efficient use of network
resources. As will be discussed further below, the additional
texture data to be streamed may advantageously be selected based
upon a position or relative distance of a structure within the
scene, and/or based upon whether the data is revealed (i.e.,
visible) in the scene.
[0031] A system 30' implemented using JPIP is illustrated in FIG.
3. In this embodiment, geospatial texture data layers 36a'-36d' are
stored in a data storage device 31' on the server 39' in a JPEG
2000 format that is arranged in a manner that permits efficient
streaming by a JPIP streaming module 41'. As the rendering program
on the processor 35' requests textures, a JPIP module 40'
translates the requests into JPIP requests. Responses are returned
in successive additive layers 36a'-36d', and each layer is
converted to a texture.
[0032] A JPIP-aware model viewer can make successive texture
requests, each time resulting in sharper and sharper textures, as
seen in FIG. 4. JPEG 2000 files may be encoded using profiles that
produce quality layers. In FIG. 4, each of the layers 36a-36d
represents a different JPEG 2000 quality layer. Each quality layer
contains a portion of each pixel's information, and each successive
layer adds to the previous ones to provide progressively sharper
pixels until the final layer contains the remaining information to
complete the full resolution image, as shown. Another example is
shown in FIGS. 5A-5C, in which three successive additive layers
result in the illustrated buildings 51 going from having an
obscured surface with little window or picture definition (51c), to
the well defined buildings 51a having relatively crisp window
delineation and a visible image of whales on the side of one of the
buildings.
[0033] Referring additionally to FIG. 7, in accordance with another
advantageous aspect models/scenes that are farther away from the
user need only receive lower resolution textures, and the user is
advantageously not burdened with downloading unnecessary texture
data. That is, the processor 35'' may advantageously prioritize
retrieval and display of successive additive layers of resolution
of geospatial texture data to different 3D geospatial structures
within the scene on the display 34'' (Blocks 68-72). By way of
example, the processor 35'' may prioritize based upon relative
distances of the 3D geospatial structures within the scene on the
display, and/or based upon different relative areas of the 3D
geospatial structures within the scene on the display. Thus, for
example, buildings/terrain that are closer in the scene would
receive more successive additive layers of resolution than
buildings/terrain that is farther away in the scene.
[0034] Moreover, as will be appreciated by those skilled in the
art, as the user selects a given POV within the scene, the POV will
determine revealed portions (e.g., front of buildings) and obscured
portions (e.g., back of buildings) of 3D geospatial structures
and/or terrain within the scene on the display. Further, the
processor 35'' may advantageously selectively retrieve geospatial
texture data based upon the revealed portions and not the obscured
portions of the 3D geospatial structures within the scene on the
display 34''. Thus, further bandwidth savings are provided by not
downloading portions of the scene that are not going to be
displayed on the display 34'' anyway from the given POV.
[0035] The invention may also be embodied in a computer-readable
medium having computer-executable instructions for causing a
computer, such as the processor 35, to perform the steps/operations
set forth above, as will be appreciated by those skilled in the
art.
[0036] Many modifications and other embodiments of the invention
will come to the mind of one skilled in the art having the benefit
of the teachings presented in the foregoing descriptions and the
associated drawings. Therefore, it is understood that the invention
is not to be limited to the specific embodiments disclosed, and
that modifications and embodiments are intended to be included
within the scope of the appended claims.
* * * * *