Facial Reconstruction from Sparse Markers via Local Geometric Indexing

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Solution Overview

Problem

Existing facial reconstruction techniques from sparse motion capture marker data face challenges in balancing overfitting and underfitting, resulting in overly smooth or overly detailed reconstructions, and require high computational resources.

Innovation Solution

The method employs local geometric indexing to identify relevant shapes from a high-resolution facial shape dataset, merging these to create a facial reconstruction using tetrahedral meshes and natural neighbor interpolation, which allows for a dense mesh with high detail from sparse input positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional facial reconstruction techniques are used, then computational resources are consumed, but the reconstruction quality becomes either overly smooth or overly detailed

Engineering Contradiction:
Improvefacial reconstruction qualityVSAvoidcomputational resources
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent segments the facial reconstruction process into distinct modules: (1) extracting 3D positions of facial markers, (2) retrieving corresponding local geometric shapes from a pre-built database, (3) merging retrieved shapes using Voronoi diagram-based partitioning, and (4) blending shapes using natural neighbor interpolation. This segmentation allows each module to be optimized independently, reducing overall computational resource consumption while maintaining high reconstruction quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary actions by pre-building a comprehensive facial shape database containing diverse local geometric shapes before the actual reconstruction process. During reconstruction, the system only needs to retrieve and combine pre-processed shapes rather than generating them from scratch, significantly reducing real-time computational resources while improving reconstruction efficiency and quality.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If sparse facial markers are used, then measurement precision decreases, but device complexity and computational requirements increase

Engineering Contradiction:
Improvesystem complexityVSAvoidfacial marker data density
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent uses a database of pre-captured high-resolution facial shapes as templates or copies of actual facial geometry. The sparse marker data serves only to identify which pre-existing shape copies to retrieve and combine, rather than requiring dense markers to capture full facial geometry. This copying approach maintains high measurement precision while using minimal markers and reducing system complexity.

Inventive Principle:
Principle #26Copying

3Manufacturing precision

If overfitting is avoided, then reconstruction detail is lost, but if underfitting is avoided, then excessive detail and noise are introduced

Engineering Contradiction:
Improvefacial detail accuracyVSAvoidreconstruction stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies local quality by retrieving and merging specific local geometric shapes corresponding to each facial marker's location rather than applying a uniform reconstruction approach across the entire face. Each region is reconstructed using shapes locally appropriate to that facial area, maintaining high detail accuracy where needed while ensuring overall stability through consistent blending using natural neighbor interpolation and Voronoi-based partitioning.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS11783493B2Obtaining high resolution and dense reconstruction of face from sparse facial markers
Publication Date: 2023.10.10 LUCASFILM ENTERTAINMENT COMPANY LTD
  • US11783493B2 patent drawing
  • US11783493B2 patent drawing
  • US11783493B2 patent drawing

AI summary

Some implementations of the disclosure are directed to techniques for facial reconstruction from a sparse set of facial markers. In one implementation, a method comprises: obtaining data comprising a captured facial performance of a subject with a plurality of facial markers; determining a three-dimensional (3D) bundle corresponding to each of the plurality of facial markers of the captured facial performance; using at least the determined 3D bundles to retrieve, from a facial dataset comprising a plurality of facial shapes of the subject, a local geometric shape corresponding to each of the plurality of the facial markers; and merging the retrieved local geometric shapes to create a facial reconstruction of the subject for the captured facial performance.