Proposed: Image to Full Body FACS

Context

This system builds a robust image-to-full-body-face mapping pipeline to capture real-world 3D full-body movements synchronized with visual data. Key metrics include anatomical accuracy of motion prediction, scalability across diverse body types, and real-time processing capabilities. This proposal addresses the growing demand for realistic full-body animation in virtual avatars, gaming, and biomechanical analysis. It matters now due to advancements in computer vision and the need for cost-effective motion capture solutions beyond lab-controlled environments.

Problem Statement

Primary operational challenges include:

  1. Lack of accessible systems for accurate 3D full-body motion capture from 2D images/video
  2. Difficulty generating anatomically plausible animations from imperfect visual data
  3. High computational costs of existing marker-based motion capture systems
  4. Limited adaptability to real-world environmental noise and occlusion

Proposed Solution

An image-to-FACS pipeline combining synthetic data generation, biomechanical constraints, and reinforcement learning:

  • Convert T-posed animations to VRM avatar format with COCO keypoint annotations
  • Generate synthetic training data using Godot Engine with marker/color variations
  • Leverage MediaPipe for video-to-keypoint conversion with vertex-based facial mapping
  • Train custom prediction models using temporal-spatial attention mechanisms

Implementation Steps:

  1. Create VRM synthetic datasets with ground truth annotations
  2. Develop MediaPipe integration for unified body-face-hand keypoint extraction
  3. Implement reinforcement learning (GRPO) for motion generation from masked video

Implementation Plan

  1. Phase 1: Synthetic Data Pipeline
    • Develop Animation-to-VRM conversion tools
    • Generate multi-format synthetic data in Godot Engine
  2. Phase 2: Keypoint Prediction Model
    • Train transformer-based model on synthetic/real data mixtures
    • Integrate biomechanical constraints into loss functions
  3. Validation:
    • Success Criteria: >90% anatomical validity in user studies
    • Failure Threshold: <15% improvement over baseline MediaPipe accuracy

Datasets

Dataset ID Description URI License
ANIM_A_POSE T-posed character animations for baseline modeling N/A Proprietary
ANIM_O3DE_COCO_FULL_BODY_FACS_RGB_8 Full-body FACS annotations with RGB video pairs N/A Apache 2.0
ANIM_O3DE_COCO_FULL_BODY_FACS_LUMINANCE_8 Luma-key marker data synchronized with RGB N/A Apache 2.0
ANIM_O3DE_MOTION_MATCHING O3DE Motion Matching dataset GitHub Apache 2.0
ANIM_QUATERNIUS_UNIVERSAL_ANIMATION_LIBRARY Universal Animation Library N/A CC0 1.0
ANIM_100_STYLES Multi-style character animation dataset N/A Proprietary
COCO_2017_KEYPOINTS COCO person keypoints dataset Kaggle CC BY 4.0
COCO_YOGA_16 Yoga pose classification dataset Kaggle MIT

Benefits

  • Enables markerless full-body motion capture from consumer-grade video
  • Maintains facial-phonetic synchronization during body movements
  • Reduces dependency on expensive motion capture hardware
  • Supports real-time applications through efficient architecture design

Risks and Limitations

  • Potential error accumulation in long-term motion prediction
  • Challenges maintaining facial-hand-body coordination
  • Dependency on quality synthetic training data
  • Computational intensity of real-time 3D mesh processing

Alternatives Considered

Option Pros Cons
Commercial mocap suits High accuracy Cost-prohibitive, lab-bound
Pure ML approaches Fully automated Limited anatomical plausibility

When to Avoid This Solution

Not suitable for applications requiring medical-grade biomechanical accuracy or environments with persistent heavy occlusion.

Organizational Alignment

Supports strategic goals in virtual humanoid development and aligns with open-source initiatives for accessible animation tools.

Proposal Status

Status: Proposed

Decision Makers

  • Fire

Tags

  • Computer Vision
  • Biomechanics
  • Virtual Avatars
  • Real-Time Systems

References

  1. MediaPipe Integration Codebase
  2. VRM Avatar Specification
  3. GRPO Algorithm Documentation