Avatar Animation Muscle Group Modeling for Realistic Visemes

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Solution Overview

Problem

Conventional facial animation systems struggle to accurately and realistically render human facial movements, particularly during speech, due to the complex interactions of multiple muscle groups, resulting in unrealistic and inaccurate facial motions.

Innovation Solution

The system identifies and models the characteristics of muscle groups as they move into and out of different positions to produce specific visemes, using machine learning to analyze individual muscle characteristics and apply them to computer-generated avatars, enabling realistic reproduction of facial expressions and body actions in real-time, regardless of the avatar's topology or geometry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional facial animation systems are used to render human facial movements, then the system is simple to implement, but the realism and accuracy of facial motions deteriorate due to inability to model complex muscle group interactions

Engineering Contradiction:
Improverealism and accuracy of facial motionsVSAvoidcomplexity of muscle group modeling
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system segments the facial animation problem by identifying and modeling individual muscle groups (e.g., orbicularis oculi, zygomaticus major) separately. Each muscle group is associated with specific action units (AUs) that control particular facial features. This segmentation allows complex facial expressions to be constructed from simpler, independently modeled muscle components, resolving the contradiction between modeling accuracy and system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes parameters by introducing muscle-specific control parameters including onset curves (describing how muscle intensity increases from neutral position), falloff curves (describing how muscle intensity decreases), and peak transition velocity constraints. These parameter changes enable realistic muscle behavior simulation while maintaining manageable system complexity through standardized mathematical models.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If detailed muscle group modeling is implemented to achieve realistic facial expressions, then the animation accuracy improves, but the computational resources and processing time increase

Engineering Contradiction:
Improveaccuracy of facial expression reproductionVSAvoidcomputational resources required
Core Design Contradiction:
Manufacturing precisionVSPower

Solution Approach 1:

The system applies partial action by selectively activating only the necessary subset of muscle groups and action units required for each specific facial expression or viseme. Rather than computing all possible muscle interactions continuously, the system activates only relevant muscles based on the target expression, reducing computational overhead while maintaining accuracy for the required expressions.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system performs preliminary action by pre-defining muscle group properties, action unit configurations, onset curves, and falloff curves during system setup. This pre-computation of muscle behavior parameters eliminates the need for complex real-time calculations during animation rendering, as the system only needs to apply pre-established muscle models and curves to generate realistic facial motions.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If real-time avatar animation with lifelike facial motions is provided, then the quality of communication improves, but the bandwidth requirements increase

Engineering Contradiction:
Improvequality of facial animationVSAvoidbandwidth requirements
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The system extracts only the essential facial motion data required for realistic communication by focusing on viseme-specific muscle group activations. Rather than transmitting complete 3D facial geometry or all possible expression parameters, the system extracts and transmits only the critical muscle activation patterns and timing curves needed to reconstruct lifelike facial motions at the receiving end, significantly reducing bandwidth requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS11468616B1Systems and methods for improving animation of computer-generated avatars
Publication Date: 2022.10.11 META PLATFORMS TECHNOLOGIES LLC
  • US11468616B1 patent drawing
  • US11468616B1 patent drawing
  • US11468616B1 patent drawing

AI summary

The disclosed computer-implemented method may include identifying a set of action units (AUs) associated with a face of a user. Each AU may be associated with a muscle group engaged by the user to produce a viseme associated with a sound produced by the user. The method may also include, for each AU in the set of AUs, determining a set of AU parameters associated with the AU and the viseme. The set of AU parameters may include (1) an onset curve, and (2) a falloff curve. The method may also include (1) detecting that the user has produced the sound, and (2) directing a computer-generated avatar to produce the viseme in accordance with the set of AU parameters in response to detecting that the user is producing the sound. Various other methods, systems, and computer-readable media are also disclosed.