Single-Image 3D Hair Reconstruction with Dual Geometry-Texture Spaces

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Solution Overview

Problem

Existing systems struggle to provide an end-to-end solution for 3D hair reconstruction and rendering from a single reference image, as they either focus on geometry reconstruction with smooth results or require manually created input geometries, failing to integrate both geometry reconstruction and appearance capturing.

Innovation Solution

A 3D try-on pipeline utilizing a 3D implicit representation and a 2D parametric embedding space to reconstruct hair shape and texture from a single image, incorporating pixel-aligned implicit functions and neural networks to estimate obstructed portions and generate photo-realistic novel views.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If geometry reconstruction methods are used, then 3D shape can be obtained, but the results are too smooth to guide detailed rendering and lack appearance details

Engineering Contradiction:
Improvegeometry reconstruction accuracyVSAvoidrendering detail quality
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent segments the hair representation into two distinct components: a 3D implicit representation for geometry structure and a 2D parametric embedding space for appearance texture. This segmentation allows each component to be optimized independently - the 3D implicit function provides accurate geometric reconstruction while the 2D embedding captures detailed appearance characteristics, resolving the contradiction between geometry accuracy and rendering detail.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent embeds the 2D parametric embedding space within the 3D implicit representation framework. The 2D appearance features are nested inside the 3D geometric structure, allowing the detailed appearance information to be integrated with the accurate geometry. This nested structure enables both precise geometry reconstruction and detailed appearance rendering to coexist.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Manufacturing precision

If neural-based hair rendering is used, then appearance can be captured, but it requires manually created or formatted input geometries that are vastly distinct from image-reconstructed geometries

Engineering Contradiction:
Improveappearance capturing qualityVSAvoidinput geometry format requirements
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent creates a universal framework where the 3D implicit representation serves multiple functions: it provides the geometric structure needed for rendering and simultaneously acts as the input format for the neural-based appearance capturing. This eliminates the need for separate manually created geometries or specialized input formats, as the same 3D implicit function output from image reconstruction can be directly used with neural networks for appearance extraction.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces a coordinate transformation mechanism as an intermediary between the 3D implicit representation and the 2D parametric embedding space. This intermediary layer bridges the gap between geometry reconstruction and appearance capturing, allowing the system to accept standard image-reconstructed geometries and automatically transform them into the appropriate format for neural-based appearance extraction, eliminating complex manual formatting requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If existing 3D hair reconstruction systems are used, then geometry can be reconstructed, but they fail to integrate both geometry reconstruction and appearance capturing in an end-to-end manner

Engineering Contradiction:
Improvegeometry reconstruction accuracyVSAvoidend-to-end solution capability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent merges the geometry reconstruction pipeline and appearance capturing pipeline into a single integrated end-to-end system. The 3D implicit representation and 2D parametric embedding space are combined within one unified framework that processes a single input image through coordinated operations, eliminating the need for separate pipelines and manual intervention. This integration achieves both accurate geometry reconstruction and appearance capturing in one cohesive process.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentUS12374036B2Single image three-dimensional hair reconstruction
Publication Date: 2025.07.29 SNAP INC
  • US12374036B2 patent drawing
  • US12374036B2 patent drawing
  • US12374036B2 patent drawing

AI summary

A system to enable 3D hair reconstruction and rendering from a single reference image which performs a multi-stage process that utilizes both a 3D implicit representation and a 2D parametric embedding space.