U.S. patent application number 10/412828 was filed with the patent office on 2003-10-16 for system for designing and rendering personalities for autonomous synthetic characters.
This patent application is currently assigned to Fuji Xerox Co., Ltd.. Invention is credited to Bickmore, Timothy W., Churchill, Elizabeth, Cook, Linda K., Prevost, Scott A., Sullivan, Joseph W..
Application Number | 20030193504 10/412828 |
Document ID | / |
Family ID | 23103271 |
Filed Date | 2003-10-16 |
United States Patent
Application |
20030193504 |
Kind Code |
A1 |
Cook, Linda K. ; et
al. |
October 16, 2003 |
System for designing and rendering personalities for autonomous
synthetic characters
Abstract
Personality traits displayed on a workbench are grouped into a
character profile that is utilized in determining the personality
and/or specific actions of a synthetic character. The personality
traits are selectable by an operator from graduated dials. The
personality traits may also be displayed in the form of selectable
attributes or trait indicative behaviors that, when selected, are
mapped into predetermined amounts of each trait in the character
profile. The character profile is utilized to compute activation
levels for primary behaviors, which are selected to influence or
direct behavior of the synthetic character. Secondary behaviors are
also selected, but discarded if conflicting with the selected
primary behaviors. When behaviors are selected, the corresponding
behaviors are translated into classes of `personality effectors`
that modulate the synthetic character's behavioral expression to
reflect the desired set of traits.
Inventors: |
Cook, Linda K.; (Sacramento,
CA) ; Bickmore, Timothy W.; (Somerville, MA) ;
Sullivan, Joseph W.; (San Francisco, CA) ; Churchill,
Elizabeth; (San Francisco, CA) ; Prevost, Scott
A.; (San Francisco, CA) |
Correspondence
Address: |
MARTIN C. FLIESLER, ESQ.
FLIESLER DUBB MEYER & LOVEJOY LLP
Fourth Floor
Four Embarcadero Center
San Francisco
CA
94111-4156
US
|
Assignee: |
Fuji Xerox Co., Ltd.
Xerox Corporation
|
Family ID: |
23103271 |
Appl. No.: |
10/412828 |
Filed: |
April 14, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10412828 |
Apr 14, 2003 |
|
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09287521 |
Apr 7, 1999 |
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Current U.S.
Class: |
345/473 |
Current CPC
Class: |
G06T 2213/12 20130101;
G06T 13/40 20130101 |
Class at
Publication: |
345/473 |
International
Class: |
G06T 015/70 |
Claims
What is claimed is:
1. A system for designing personalities for synthetic characters,
comprising: a personality trait selection device that displays at
least one selectable personality trait; and a personality builder
that groups the selected personality traits into a character
profile.
2. The system according to claim 1, wherein: said personality trait
selection device comprises at least one trait indicator, each trait
indicator representing an amount of a corresponding one of the
selectable personality traits; and said personality builder weights
each selected personality trait in said character profile according
the amount of each selected personality trait represented in the
corresponding trait indicator.
3. The system according to claim 2, wherein the trait indicators
are graduated dials operating between a high anchor and a low
anchor.
4. The system according to claim 2, further comprising: a
personality attribute selection device that displays at least one
selectable personality attribute; and a mapper configured to map
each selected personality attribute into amounts of the trait
indicators according to an amount each selected personality
attribute is represented in the selectable personality traits.
5. The system according to claim 2, wherein the selectable
personality traits include at least one primary trait of dominance,
warmth, conscientiousness, emotional stability, and openness.
6. The system according to claim 2, further comprising: a trait
indicative behavior selection device that displays at least one
selectable trait indicative behavior; and a mapper configured to
map each selected trait indicative behavior into amounts of the
trait indicators according to an amount each selected personality
attribute is represented in the selectable personality traits.
7. The system according to claim 1, wherein said character profile
comprises a translation of the selected personality traits into a
weighted set of personality traits.
8. The system according to claim 1, further comprising: a physical
modification device configured to modify physical characteristics
of said synthetic character based on the character profile.
9. A method of rendering a personality, comprising the step of:
rendering at least one behavior of a synthetic character based on a
character profile having selected personality traits.
10. The method according to claim 9, wherein said step of rendering
includes the step of: specifying at least one trait indicative
behavior; and implementing behaviors consistent with the trait
indicative behaviors.
11. The method according to claim 10, wherein: said trait
indicative behaviors include at least one primary behavior; said
step of specifying includes the step of specifying a set of
releasing mechanisms associated with the specified primary
behaviors; and said step of rendering includes the steps of,
interpreting stimuli external to said personality based on said set
of releasing mechanisms, and rendering said at least one behavior
of the synthetic character based on the interpreted external
stimuli.
12. The method according to claim 9, wherein said step of rendering
comprises the steps of: specifying at least one secondary behavior;
and implementing the secondary behaviors as one of persistent and
episodic behaviors.
13. The method according to claim 9, wherein said step of rendering
comprises the step of: modulating an existing behavior based on the
character profile.
14. The method according to claim 9, wherein said step of rendering
comprises the step of: modifying a construal process utilized by
the personality.
15. The method according to claim 14, wherein said construal
process includes processes for perception and assessment of
situations in an environment of which the personality is
located.
16. A method of selecting behavior for a synthetic character,
comprising the steps of: computing an primary activation level of
primary behaviors in each of plural nodes at a given level of a
modified behavior hierarchy; selecting a node having a highest
activation level; and executing the primary behavior in accordance
with an action defined by the selected node.
17. The method according to claim 16, further comprising the steps
of: computing an secondary activation level for at least one trait
indicative secondary behavior in each of plural nodes at the given
level of the behavior hierarchy; disregarding secondary behaviors
that conflict with the selected primary behavior; selecting
secondary behaviors based on the secondary behavior activation
level computed; repeating said steps of computing, disregarding,
and selecting until no degrees of freedom unused by the primary and
selected secondary behaviors sufficient to activate any remaining
secondary behaviors exist; and executing the selected secondary
behaviors.
18. The method according to claim 16, wherein: said step of
computing comprises, determining values, including at least one of
a level of interest, a value of inhibitory links, a value of
releasing mechanisms, a level of fatigue, and a value of endogenous
variables associated with a behavior, for factors related to
whether a behavior should be activated, and computing said primary
activation level based on the values determined.
19. The method according to claim 18, further comprising the step
of: increasing said level of fatigue associated with a behavior
based on a length of time said behavior has been activated.
20. The method according to claim 19, further comprising the step
of: biasing an activation level for plan steps based on a plan.
Description
COPYRIGHT NOTICE
[0001] A portion of the disclosure of this patent document contains
material which 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.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to human-computer interfaces (HCI).
The invention is more particularly related to a tool set for
modeling and creation of a personality for an animated
anthropomorphic character HCI that interacts with a user. The
invention is even more particularly related to a tool set that
allows the inclusion of new and the modification of existing
personality attributes to produce a unique and engaging
anthropomorphic character personality.
[0004] 2. Discussion of the Background
[0005] Autonomous synthetic computer characters have become a
technological and commercial reality in the last few years, both as
alternative user interface mechanisms and as entertainment devices.
The Microsoft Office Assistant, Microsoft Agent, IBM's Warp Guide,
and Extempo's Imp Software are all recent attempts to commercialize
user interface technology developed over the last decade at
academic research institutions. The explosion in computer games
which utilize synthetic characters and their increased use in
television and motion pictures also indicate a strong demand for
advances in this technology.
[0006] One such advance is the basic action selection architecture
(BASA) developed in the ALIVE project at the MIT Media Lab. The
BASA is used for run-time simulation of characters in deliverable
applications.
[0007] In the BASA, behaviors are arranged in a hierarchy with
those at the top of the hierarchy being more abstract categories of
behavior and those at the bottom being operational in that they
have simulation routines associated with them which allow the
character to perform them when commanded. Behaviors at each level
in the hierarchy compete every time step of the simulation for
control of the character. The result of this competition is one
primary behavior, which is the primary action the character
performs at that time step.
[0008] However, most of the research and development in this area
to date has been on realistic rendering, real-time animation, and
"functional" autonomous behavior, while the issue of character
personality is typically left for an animator or script writer to
fashion in an "artistic" (i.e., unprincipled) manner.
SUMMARY OF THE INVENTION
[0009] The present inventors have realized the need to utilize
personality in efforts to develop better synthetic characters, and
the need for a method to apply personality to synthetic characters.
The present inventors have also realized that the application of
certain personality traits to synthetic characters can make the
synthetic characters more engaging, and more quickly accepted by
users, easing the learning and familiarization process of an
application to which the synthetic characters are applied.
[0010] Accordingly, it is an object of the present invention
provide developers a workbench for developing and creating
personalities for synthetic characters.
[0011] It is another object of the present invention to provide a
workbench that allows personality traits to be programmed into a
synthetic character developed for an application within a BASA-like
architecture.
[0012] It is yet another object of the present invention to modify
a behavioral hierarchy of a BASA architecture and provide for the
selection of primary and non-conflicting secondary behaviors
implementing personality traits of a character profile.
[0013] The present invention describes a system for designing
recognizable personalities in synthetic computer characters in
order to better engage users. A personality design workbench
enables designers to describe personality attributes that modify a
behavioral hierarchy, particularly useful for characters created in
a simulation environment having a reactive action selection
architecture. These systems may be utilized to build applications
for conversational characters (anthropomorphic user interfaces) and
for entertainment purposes.
[0014] Typically, known characters share the same behavioral sets
and display only minimal, if any, inter-character individuation. To
broaden personality expression in such characters (individuation),
the personality design workbench outputs a set of `personality
effectors` able to modify a prescribed set of behaviors within a
BASA behavioral hierarchy to clearly portray uniquely different
character personalities.
[0015] These and other objects are accomplished by a system for
rendering personalities for synthetic characters, including a
personality trait selection device that displays at least one
selectable personality trait, and a personality builder that groups
the selected personality traits into a character profile.
[0016] The personality trait selection device may include trait
indicators (graduated dials, for example), each trait indicator
representing an amount of a corresponding one of the selectable
personality traits. The personality builder weights each selected
personality trait in said character profile according the amount of
each selected personality trait represented in the corresponding
trait indicator.
[0017] The system may also include a personality attribute
selection device that displays at least one selectable personality
attribute, and a mapper configured to map each selected personality
attribute into amounts of the trait indicators according to an
amount each selected personality attribute is represented in the
selectable personality traits.
[0018] The invention includes a method of selecting behavior for a
synthetic character, comprising the steps of computing a primary
activation level of primary behaviors in each of plural nodes at a
given level of a modified behavior hierarchy, selecting a node
having a highest activation level, and executing the primary
behavior in accordance with an action defined by the selected node.
The method may include selecting a secondary behavior level, and
discarding the secondary behavior if it conflicts with a selected
primary behavior.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] A more complete appreciation of the invention and many of
the attendant advantages thereof will be readily obtained as the
same becomes better understood by reference to the following
detailed description when considered in connection with the
accompanying drawings, wherein:
[0020] FIG. 1 is an overview of a process for utilizing a workbench
for developing a personality to be applied to one or more synthetic
characters;
[0021] FIG. 2 is an example of a behavioral hierarchy useful for a
conversational character;
[0022] FIG. 3 is a diagram illustrating influences on a behavior
for determination of a behavior activation level;
[0023] FIG. 4 is a classification hierarchy of personality
effectors for implementing character traits; and
[0024] FIG. 5 is a block diagram of one embodiment of a device for
rendering a personality.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The present inventors have realized that a consistent,
readily-identifiable personality is crucially important in
synthetic character applications for at least the following
reasons:
[0026] Personality helps to engage the user. Both anthropomorphic
interfaces and entertainment applications require that the user
"suspend disbelief" while using them. A character with a
well-designed personality can not only attract users into using a
system but can help maintain the illusion that they are interacting
with a real entity.
[0027] Personality facilitates user identification with the
character in "ally" interfaces. In Conversational Character systems
in which the character acts as the user's ally in using a complex
system, a properly designed personality can increase the user's
sense of allegiance with the character.
[0028] Personality can be used to establish the user's expectations
about the system. A character with a dominant personality will be
expected to lead the user in mixed-initiative interactions; a
submissive character will be expected to do the opposite.
[0029] Personality can be used to control the user's style of
interaction with the system. An immature or child-like character
can be used to subconsciously coax the user into speaking slowly to
accommodate imperfections in the speech recognition system.
[0030] Personality can be used to control the user's affective
response to the system. People have affinity for others who have
personalities similar to theirs and even greater affinity for those
who modify their personality to be more like them. Such phenomena
could be leveraged to make users like a particular product more
than they would otherwise.
[0031] Personality is central for entertainment applications.
Personality is central to character development which is crucial to
any story upon which an entertainment system may be based.
[0032] The present inventors have realized that personality may be
utilized as an additional tool to develop better synthetic
conversational characters and consequently better software
applications. At a minimum, conversational characters provide a
more familiar mode of communication for users enabling the
character to have a more congenial relationship such as a mentor or
assistant to the user. The capacity to augment these characters
with identifiable personalities can produce not only richer
applications but also considerable design enhancements for the
developer.
[0033] Users will find personable synthetic characters to be more
engaging, more comfortable and ultimately easier with which to
work. The benefits for fielded applications are clearly evident:
ease of learning and tool familiarization, more ready acceptance by
users and an application that is more highly regarded. From a
design perspective, developers can more readily tailor multiple
versions of an application for different classes of user and
experiment with different aspects of personality to improve
engagement with or enhance user acceptance of new applications.
[0034] The present inventors have developed a novel approach to
modeling personality. The model is the basis for a personality
design workbench that assists developers in creating personable
characters and also underlies a personality engine that realizes
design specifications within character behavior. The design
process, workbench and character realization are schematically
depicted in FIG. 1.
[0035] The personality design workbench (personality workbench, or
simply workbench) outputs characters which are constructed to be
used within a specific reactive action selection architecture
designed for autonomous synthetic character applications (BASA
architectures, for example). The personality workbench may also
output characters for other (or multiple) architectures. The
specific reactive action selection architecture is ethological in
origin and models how characters choose their behaviors based on
constructs such as internal and external states, releasing
mechanisms, inhibition and fatigue. Behavior selection at each
cycle in the system is determined by the outcome of a summative
relationship between these factors in a `winner take` all
competition that ensures that the character maintains coherency in
its behavior.
[0036] The two problems addressed by the personality design
workbench are:
[0037] 1) how should personality be specified by a character
designer; and
[0038] 2) how to map from the desired personality specifications to
the selection of character behaviors such that those behaviors will
clearly reflect the intended personality.
[0039] The present invention presents a method for formalizing
personality expression by drawing on research from two disciplines:
personality trait theory and human communication theory. Trait
theory suggests that people clearly communicate notions of
personality with descriptive, trait-like words found in their
cultural lexicon. These personality-based linguistic constructs or
`labels` are used by people to both describe and classify people
based on behavioral similarities. Research has clearly demonstrated
that traits are highly stable predictors of future behavior, that
people use only the features associated with a small set of traits
when classifying individual personalities and there is a high
degree of consensus about the typical behavioral descriptors
associated with specific traits. For example, most people describe
introverts as being quiet, shy and retiring. It is clear, however,
that the descriptors `quiet, shy and retiring` do not provide
sufficient data upon which to create an introverted character.
[0040] In human communication theory, personality is seen as part
of a dynamic, communicative process--it is both emitted (or
encoded) by an individual and subsequently `decoded` by a viewer.
As encoders, humans display aspects of their personality across
multiple independent channels which tend to be predominantly
nonverbal in nature (e.g., posture, gross body movement, facial and
eye expression, or hand gestures). Likewise, as decoders humans
read from and combine information across multiple channels to form
an overall impression of both the person and their message. Thus,
research has shown that introverts tend to display the following
kinds of behavior: they speak little and only when spoken to, they
assume a closed body posture and they tend to avoid eye contact. If
a person (or an embodied character) were to display these behaviors
they would be labeled as introverts. Our methodological approach is
thus to isolate a basic set of personality traits and trait
indicative nonverbal and verbal behaviors (i.e. people believe the
behavior reflects a specific trait), and, finally translate those
behaviors into classes of `personality effectors` that can modulate
a character's behavioral expression within the simulation
environment so as to reflect the desired set of traits.
[0041] There have been a number of research projects examining
personality from two perspectives: the effects of personality on
non-anthropomorphic interface design (User Interface Design) and
the impact of personality on agent behavior in interactive,
fictional worlds (Interactive Worlds).
[0042] User Interface Design
[0043] IBM's software agent WarpGuide is an agent-oriented task
guide that assists people with system tasks. It employs a
personality (intelligent, friendly and unobtrusive) that was deemed
task-appropriate (i.e. a mentor), a weak physical rendering of that
personality (i.e. text boxes with rounded corners, warm colors) and
a message content that was biased along the same personality
dimensions. Experimental studies suggested users responded
positively to the characterization. However, since the actual
interface was limited to text, these "agents" did not address the
use of multiple simultaneous channels for conveying personality
(including, in particular, human trait-indicative non-verbal
behaviors).
[0044] Interactive Worlds
[0045] In The Virtual Theater project at Stanford, use a
social-psychological model of personality. However, it has many
deficiencies: 1) it is only able to select one behavior per time
step (simultaneous use of multiple channels is not possible); 2)
the basic action selection approach is severely impoverished (no
perception, no coherence of action, and boredom/fatigue is modeled
by randomization); 3) no provision integrating more complex,
deliberative behavior (e.g., task planning, face-to-face
communicative behavior); 4) use of traits and non-verbal behaviors
is ad-hoc; and 5) personality models are difficult and confusing to
author, and difficult to predict given that traits can change over
time.
[0046] Both the OZ project at CMU and the Affective Reasoner
project at DePaul use a cognitive model of emotion based on Ortony.
The emotion module in OZ reasons over recent events and the agent's
goals to create an emotional interpretation of the current status
of the system. Emotions are generated by comparing an event outcome
to an agent's current goals (e.g., goals succeed/fail which result
in happy/sad emotional states). The emotional interpretation (if
any) is returned to the behavior engine for use in selecting the
agent's next behavior--allowing emotion to play a role in behavior
selection. Elliot's Affective Reasoner uses the same emotion model
as OZ but gives agents a rudimentary personality using two related
constructs: disposition and temperament. Disposition is an
`interpretive` personality construct that enables agents to
differentially interpret events. Temperament is the `manifestive`
component of personality that guides an agent's expression of
emotional state in its behavior. Neither of these approaches
utilize a trait-based specification of personality nor
trait-indicative non-verbal behaviors. The Oz project utilized very
primitive synthetic characters which could only exhibit one
behavior at a time (multiple simultaneous channels are not
available); the Affective Reasoner is a text-only system.
[0047] The present invention has the following features: 1) An
approach based on extensions to an ethologically-correct action
selection architecture; 2) the personality "workbench" provides
multiple simple authoring mechanism; 3) all information about
personality and its behavioral effects are encapsulated with a
character; 4) a character can portray persistent trait-indicative
non-verbal behaviors through "persistent personality effectors"; 5)
a character can portray conditional and temporally-bounded
trait-indicative non-verbal behaviors through "episodic personality
effectors"; 6) a character can portray trait-indicative actions in
response to user actions through "reactive personality effectors";
7) a character can modulate how it performs actions via "modulating
personality effectors"; 8) a character can alter its perception and
assessment (construal) of situations in its environment through
"construal personality effectors"; 9) the workbench will suggest
non-behavioral modifications to the physical design of the
character; 10) characters can use multiple simultaneous
communication channels to project personality; 11) the selection of
traits and non-verbal behaviors used are based on research in
psychology and communications; and 12) personality is presented as
indigenous to a character.
[0048] 1. The approach is based on extensions to an
ethologically-correct action selection architecture.
[0049] The "personality workbench" produces extensions and
modifications to a basic action selection architecture. This
architecture ensures natural, coherent behavior while allowing for
multiple, simultaneous actions, based on the character's perception
of its environment, internal state and level of boredom and
fatigue. This model can be readily extended to perform deliberative
actions such as task planning.
[0050] 2. The personality "workbench" provides multiple simple
authoring mechanism.
[0051] Character designers can specify personality either by direct
manipulation of trait values (e.g., a value between -10 and +10 on
the warm/cold dimension), through the selection of desired trait
attributes (e.g., a character which is kind, sympathetic,
soft-hearted and affectionate), or via selection of desired
non-verbal behaviors (e.g., makes frequent and expansive gestures).
Limited editions, combinations, and variations of the above
mechanisms are also envisioned.
[0052] 3. All information about personality and its behavioral
effects is encapsulated within a character.
[0053] Trait-indicative nonverbal signaling behaviors and
mechanisms for personality-biased modulation of behavior are
organized in a set of modular data structures. These data
structures, called "personality effectors", enable multi-faceted
personality expression which is enduring, consistent and
predictable across time and events.
[0054] 4. A character can portray persistent trait-indicative
non-verbal behaviors through "persistent personality effectors"
[0055] Personality descriptions are used to select non-verbal
behaviors that act as "default" behaviors for the character. They
are subtle, have a high frequency of occurrence and will always be
expressed whenever they do not conflict with the primary behavior
the character is executing. Examples are body posture (e.g.,
slumped) and facial expression (e.g., frown).
[0056] 5. A character can portray conditional and
temporally-bounded trait-indicative non-verbal behaviors through
"episodic personality effectors"
[0057] Like persistent behaviors these are largely nonverbal in
nature and unconscious. Unlike persistent behaviors they appear
only periodically, under well specified time constraints and are
competitive with other behaviors for activation. Examples are
self-face touching as a signal of nervousness and gaze avoidance as
a signal of submissiveness.
[0058] 6. A character can portray trait-indicative actions in
response to user actions through "reactive personality
effectors".
[0059] For task-oriented application domains in which the character
and user have goals they are trying to achieve, the workbench will
produce behaviors which enable the character to respond in a
trait-indicative manner to actions taken by the user. Examples are
facial flush (submissive) or violence (dominant) when the user
thwarts a goal of the character.
[0060] 7. A character can modulate how it performs actions via
"modulating personality effectors".
[0061] Modulating personality effectors change how the character
performs a given action. These are essentially hints to the various
behavior routines which suggest, for example, that if the character
needs to walk it should walk decisively (dominant) or nervously
(tense). These effectors can also modify the performance of
linguistic components of conversational characters by effecting
word choice and sentence structure decisions (e.g., "Could you
possibly spare something to drink?" vs. "Give me some water!").
Modulating effectors can also be systemic in that they effect how
the action selection architecture itself functions by modifying the
amount of deliberation performed by the system, the boredom and
fatigue decay rates, etc.
[0062] 8. A character can alter its perception and assessment
(construal) of situations in its environment through "construal
personality effectors".
[0063] Different personality types see the world differently. For
example, tense character will react more rapidly to an approaching
user than a relaxed one will.
[0064] 9. The workbench will suggest non-behavioral modifications
to the physical design of the character.
[0065] These suggestions include both invariant physical features
(body type, facial structure), variable personal artifacts, and
suggestions for designing the character's setting (furniture,
etc.).
[0066] 10. Characters can use multiple simultaneous communication
channels to project personality.
[0067] Nonverbal behaviors appear in multiple, readily identifiable
channels (i.e. face, posture, etc.), they can be expressed in
parallel (appear in two or more channels simultaneously) and often
carry redundant messages. Having multiple concurrent communication
channels through the use of secondary behaviors will affect
character-to-human communication in several fundamental ways:
[0068] Additional information channels broaden the communication
bandwidth and thus increases the amount of information being
conveyed at any one point.
[0069] Cross channel message redundancy or the tendency for more
than one channel to carry the same message increases the
probability that a character will be compatible with a wider range
of users. For example, men tend to look more closely at hand
gestures while women track eye behavior and facial expression.
Concurrent channels that carry the same message will reach a
broader audience.
[0070] Characters who express personality using trait-indicative
nonverbal behaviors closely mimic how humans tend to encode their
own communicative messages and to decode the messages of others.
This increased compatibility (or match) between a character and an
end-user will have a number of benefits:
[0071] An increase in the engagement level of an end-user resulting
in shorter learning curves.
[0072] Increased trust or confidence in a character's ability to
assist an end-user (i.e. end-users come to see the character as an
`ally` rather than a part of the complex system with which they are
working).
[0073] End users will value the technology more highly (Reeves and
Nass).
[0074] 11. The selection of traits and non-verbal behaviors used
are based on research in psychology and communications.
[0075] The traits, trait attributes, and associated verbal and
non-verbal behaviors used in the personality workbench are all
based on psychology and human communication research.
[0076] 12. Personality is assumed to be indigenous to a
character.
[0077] The present invention presents a personality wholly
integrated across all aspects of character realization including
subsystems for appraisal, reactive behavior selection, persistent
and episodic behavior selection and modulation. All subsystems act
in accordance to present a pervasive, robust and consistent
personality that remains intact over time.
[0078] The personality of a character is created in a design phase
and leaves the workbench with a set of fully integrated personality
attributes. This is unlike other approaches which have expressed
character personality in an ad-hoc and piecemeal fashion. Character
behaviors in other systems are isolated and appear without
coordination in nonparallel behavioral subsystems. In short,
personality expression in the other approaches is non-systemic and
results in characters that appear shallow and unconvincing.
[0079] Technical Details
[0080] The "personality workbench" produces extensions and
modifications to the basic action selection architecture. The
architecture uses an ethological approach that ties behavior
selection to traditional animal-world constructs, and may be
extended to modeling human deliberative behavior.
[0081] The behaviors within a BASA are arranged in a hierarchy, as
shown in FIG. 2. Behaviors are activities which the character can
perform, with those at the top of the hierarchy being more abstract
categories of behavior and those at the bottom being operational in
that they have simulation routines associated with them which allow
the character to perform them when commanded. Behaviors at each
level in the hierarchy compete every time step of the simulation
for control of the character. The result of this competition is one
primary behavior, which is the primary action the character is
performing, and secondary behaviors. The secondary behaviors are
executed as long as they do not conflict with the primary behavior
(where `conflict` is defined with respect to the character
simulation controls). Thus, the architecture supports the
simulation of multiple parallel activities while maintaining a
notion of behavioral focus.
[0082] Behaviors from each level are selected based on a
computation of activation level and competition with sibling
behaviors. The factors which go into the calculation of activity
level are (see FIG. 3):
[0083] Endogenous variables. These correspond to internal states
such as blood sugar level, hormone levels, hunger or thirst.
Modeled as a continuous variable where a sufficiently high value
helps influence the selection of a behavior (drinking in response
to thirst).
[0084] External states and releasing mechanisms. External states
are events or objects detected in the environment by sensors.
Releasing mechanisms are `perceptual interpretations` of external
stimuli that signal an object or event is important to the
agent.
[0085] Inhibition and fatigue (level of interest). When behaviors
compete amongst each other they do so on the basis of each
behavior's activation level and inter-behavior inhibition. The
activation value is determined in part by the endogenous variables
and releasing mechanisms described previously. These two factors
cannot determine the right amount of persistence (i.e. too much
dithering between multiple behaviors) nor account for opportunistic
responses (i.e. not persisting in one behavior to the exclusion of
other goals). To model persistence, competing behaviors are assumed
to be mutually inhibiting--some behaviors can post a higher gain
for performance relative to others. The higher the gain, the
greater the persistence. Modeling opportunistic behaviors requires
some notion of time-sharing among activities. The construct of
fatigue assumes that when a behavior is selected as primary, its
level of fatigue will increase proportionally over time, which will
reduce the overall activation value of that behavior. When the
value of the current primary behavior falls below that of a
competing behavior the competing behavior will become primary.
[0086] This architecture can be further extended to simulate
elements of human deliberative behavior. In one embodiment, such
extension is performed by coupling the architecture with a task
planner. When a plan has been produced, it can be used to bias the
activation level for the behavior(s) corresponding to the next
step(s) in the plan when their preconditions are satisfied. In this
way, the reactive action selection architecture can be used as an
intelligent plan execution environment, in which unplanned
behaviors can still be performed opportunistically if
warranted.
[0087] We summarize the features of a reactive behavior selection
architecture that are particularly amenable to expressing an
integrated personality through trait-indicative behavior
selection.
[0088] Behaviors are organized in loose hierarchies with the leaf
nodes in the hierarchy containing character simulation information
(i.e. the directions about how to move the `muscles` of the
character to perform the behavior).
[0089] Character simulation information is described in terms of
specific `degrees of freedom` which refer to the points on the
character's body that can be moved. (These are a fixed set of
points and generally correspond to the joints of the character's
body.) Having a character make an expansive beckoning gesture with
its arm requires the use of three degrees of freedom--the elbow,
wrist and shoulder.
[0090] At any point in time a character will be engaged in only one
activity called a primary behavior. The primary behavior has
uncontested access to those degrees of freedom that it needs to
perform.
[0091] One or more behaviors (called secondary behaviors) can
execute simultaneously with the currently selected behavior if the
following are true:
[0092] 1. The value of the secondary behavior is sufficiently
high.
[0093] 2. The degrees of freedom necessary to perform the secondary
behavior are currently available (i.e. not being used).
[0094] Personality Design
[0095] Characters emerging from the personality design workbench
have trait profiles that will generate individuated characters. In
a primary embodiment, character trait profiles are made up of a set
of five bi-polar traits each of which varies along a continuous
dimension. The five primary traits are the standard "Big Five"
traits used most in personality theory research (see Table 1).
1TABLE 1 Trait Indices Used in Personality Workbench Primary Traits
Dominant/Submissive Warm/Cold Conscientiousness Emotional Stability
Openness
[0096] The workbench allows designers to create personality
profiles for a character in three different ways. For example, in
one embodiment:
[0097] 1. For each of the traits, the designer can position a
graduated dial at an arbitrary point between two anchors (i.e. a
highly warm character would have the dial set very near the `warm`
anchor point on the dial). Designers must set at least two of the
primary personality traits for each character. Primary traits not
set by the designer are arbitrarily given default neutral settings
that point in the middle of the anchors. A trait with a neutral
setting means that the trait would not be readily inferred from the
character's behavior (i.e. behaviors indicative of neutral-rated
traits can appear in a character's behavior but not with a
frequency that would be recognized by users.)
[0098] 2. The designer can select personality attributes they want
their character to manifest. Personality attributes are linguistic
labels which describe attributes typically associated with each
trait anchor end-point (e.g., `warm` attributes include kind,
sympathetic, soft-hearted, affectionate). The Personality Workbench
will then map these selected attributes into a trait profile which
can then be edited using method 1 above.
[0099] 3. The designer can select a set of trait-indicative
behaviors that she wants the character to perform. For example, a
designer may not know what she wants in terms of a trait profile or
attributes, but knows that she wants character which performs
gesturing behaviors that are expansive and highly frequent. The
Personality Workbench will then map these selected behaviors into a
trait profile which can then be edited using method 1 above.
[0100] Personality Effectors
[0101] The Personality Workbench translates the trait profiles for
a character into the following personality effectors which modify
the behavior of the basic action selection architecture described
above (for example, any method that would convey behaviors
associated with the character). A classification hierarchy of the
personality effectors is illustrated in FIG. 4.
[0102] Persistent personality effectors. These are new behaviors
added to the hierarchy for the character being designed. Persistent
nonverbal behaviors have a constant activation value (i.e. are
always `on`), are not subject to decay (or fatigue) over time, and
can never be selected as primary behaviors (i.e., can only be used
as secondary behaviors). They function as default behaviors as they
will always be expressed if the necessary simulation controls for
expression are available (i.e. not currently being used by the
primary behavior). Thus, persistent behaviors are constantly
opportunistic--if the conditions are favorable they will always
execute. For example, an introverted character may always exhibit a
slumped posture unless it needs to reach something.
[0103] Episodic personality effectors. These are new behaviors
added to the hierarchy for the character being designed. These
behaviors are similar to persistent behaviors in that they
represent trait-indicative nonverbal behaviors and can never be
selected as primary behaviors (they represent `unconscious`
non-deliberative actions on the part of the character). However
they act like other behaviors in the behavioral hierarchy in that
their activation values can fluctuate in response to environmental
stimuli (unlike persistent behaviors). For example, introverts tend
to display gaze avoidance behavior, but displaying that behavior
only makes sense in the presence of others.
[0104] Reactive personality effectors. These are new behaviors
added to the hierarchy for the character being designed. These
behaviors are domain-dependent, full-fledged additions to the
behavior hierarchy for a given application (i.e., they can have
endogenous influences, releasing mechanisms, and level-of-interest
functions), and represent the set of personality-specific,
deliberative actions that a character may take in response to a
given situation. For example, a dominant character may respond with
a violent behavior in response to a goal-obstruction, whereas an
introverted character may only blush.
[0105] Modulating personality effectors. These act as hints to the
action selection system, affecting how different functions are
performed rather than what functions are performed at any given
time. There are three kinds of modulating effectors: 1) behavioral,
which effect how a given behavioral simulation is executed (e.g.,
the `walk` simulation may be modified to perform `walk happily`,
`walk timidly`, `walk boldly`, or `walk sadly`); 2) linguistic,
which effect how the language synthesis parts of a Conversational
Character system function (i.e., effecting word choice and sentence
structure); and 3) systemic, which impacts the overall action
selection system (e.g., trading deliberation vs. action for a
conscientious character, increasing boredom/fatigue rates for
happy-go-lucky characters, etc.).
[0106] Construal or appraisal functions. Personality can modify a
character's interpretation of world events. In an ethological model
this would require modifications in the form of increased or
decreased gains on existing releasing mechanisms or adding new
releasing mechanisms to existing behaviors. For example, a more
submissive person would detect a dominant person sooner and would
react accordingly in their presence (i.e. displaying submissive
behaviors). At a deeper, psycho-sociological level, appraisal
functions determine the character's assessment of actions taken by
others and its impact on the character's affective state
(endogenous variables), and is driven, at least in part, by the
character's personality.
[0107] Non-behavioral effectors. Characters will have a physical
presence for which viewers will infer personality characteristics.
These features are physical in nature and are apparent throughout
the lifetime of the character. Some examples include: body type
(endomorph, ectomorph, mesomorph), facial structure
(round/triangular face), attractiveness, and physical objects that
the character may surround itself with (furniture, art, etc.). The
initial version the Personality Workbench will simply popup a
window with suggestions regarding appearance factors; future
versions may actually be able to modify the character's 3D
design.
[0108] FIG. 5 is a block diagram of one possible implementation of
a device for rendering a personality. A behavior hierarchy is
created or modified by a modifier 510. The modifier may include a
device such as the personality workbench illustrated in FIG. 1.
[0109] The behavioral hierarchy 520 provides information on primary
and secondary behaviors, modulation, and construal personality
effectors, which are each interpreted by appropriate decices
(primary activation device 552, secondary activation device 554,
modulator 540, and construal device 530, respectively). Each of
these devices provide inputs (specific action or amount of movement
in a gesture, for example) to the activation device regarding
behaviors consistent with and effecting the information in the
behavioral hierarchy.
[0110] A construal device 530 receives external stimuli 500 and
provides an interpretation of that stimuli to the activation device
550. The activation device 550 selects non-conflicting behaviors
and considers external significance of external stimuli, and
notifies a behavior execution module 560 of a selected
behavior.
[0111] At this point, it is worthwhile to review some features of
the present invention. The present invention allows a personality
profile from a design phase (such as the output of the personality
workbench described in FIG. 1) which is then translated into a new
behaviorial heirarchy via a set of personality effectors. The new
personality is an individuated behavioral hierarchy produced with
personality biased behaviors, including, primary and secondary
behaviors, modulated pre-existing behaviors, and construal changes.
The new behavioral hierarchy is created at compile time (i.e.,
before the character is running), and has the capability to (1) add
new behaviors (primary and secondary), (2) modulate existing
behaviors in an existing hierarchy, and (3) modify a character's
perception of external events.
[0112] Then, at run time, personality expression is accomplished in
the following ways:
[0113] (1) Parallel use of secondary behaviors as a way of
expressing differences between characters having a same primary
behavior (the secondary behaviors grabbing free DOFs for an
available for instantiating the secondary behavior);
[0114] (2) The use of new trait indicative primary behaviors, along
with their own internal releasing mechanisms, that were added via
the personality profile; and
[0115] (3) Modulation of existing behaviors in the hierarchy,
and/or perceptual and interpretive changes according to the
personality profile.
[0116] The present invention as discussed herein has been described
in reference to rendering a personality and methods and devices
utilized in rendering a personality, preferably for synthetic
characters. However, the teachings of the present invention may be
applied to numerous other endeavors, including equipment for
suggesting behaviors for humans, actors, electronic equipment,
voice boxes, announcement devices, or other devices not necessarily
associated with a synthetic character. In addition, the teachings
of the present invention apply to any type of animated interface or
presentation device (virtual classroom instructor, or tutor, for
example) or other animated devices or icons. The present invention
may be utilized in a computer interface or for directing operations
of any type of equipment of varying configurations (televisions,
VCR's, stereos, radar devices, toys, mechanical equipment such as
heavy machinery, and building management/maintenance devices as
just a few examples).
[0117] The present invention may be conveniently implemented using
a conventional general purpose or a specialized digital computer or
microprocessor programmed according to the teachings of the present
disclosure, as will be apparent to those skilled in the computer
art.
[0118] Appropriate software coding can readily be prepared by
skilled programmers based on the teachings of the present
disclosure, as will be apparent to those skilled in the software
art. The invention may also be implemented by the preparation of
application specific integrated circuits or by interconnecting an
appropriate network of conventional component circuits, as will be
readily apparent to those skilled in the art.
[0119] The present invention includes a computer program product
which is a storage medium (media) having instructions stored
thereon/in which can be used to program a computer to perform any
of the processes and methods of the present invention. The storage
medium can include, but is not limited to, any type of disk
including floppy disks, optical discs, DVD, CD-ROMs, microdrive,
and magneto-optical disks, ROMs, RAMs, EPROMS, EEPROMS, DRAMs,
VRAMS, flash memory devices, magnetic or optical cards, nanosystems
(including molecular memory ICs), or any type of media or device
suitable for storing instructions and/or data.
[0120] Stored on any one of the computer readable medium (media),
the present invention includes software for controlling both the
hardware of the general purpose/specialized computer or
microprocessor, and for enabling the computer or microprocessor to
interact with a human user or other mechanism utilizing the
processing of the present invention. Such software may include, but
is not limited to, device drivers, peripheral equipment programs,
operating systems, and user applications. Ultimately, such computer
readable media further includes software for performing the
functions of the present invention as described above.
[0121] Included in the programming (software) of the
general/specialized computer or microprocessor are software modules
for implementing the teachings of the present invention, including,
but not limited to, input and identification of user inputs,
selection of personality traits, building a character profile,
computing activation levels, and selection and activation of
personality behaviors including movements and speech of a synthetic
character or other animated character, voice, or display.
[0122] Obviously, numerous modifications and variations of the
present invention are possible in light of the above teachings. It
is therefore to be understood that within the scope of the appended
claims, the invention may be practiced otherwise than as
specifically described herein.
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