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DAGSM: Disentangled Avatar Generation with GS-enhanced Mesh

Conference: CVPR 2025
arXiv: 2411.15205
Code: Project Page
Area: 3D Vision / Digital Avatar Generation
Keywords: Avatar Generation, Disentangled Clothing, 3D Gaussian Mesh, Text-driven, Physical Simulation

TL;DR

DAGSM is proposed, a text-driven disentangled digital human generation method that represents the body and individual clothing items separately using GS-enhanced Mesh (GSM), supporting outfit customization, realistic animation, and texture editing.

Background & Motivation

Background

Background: Existing text-driven 3D human generation methods represent the body and clothing as a single integrated model. This prevents outfit swapping, results in unrealistic animations (with clothes adhering to the body), and offers limited user control over clothing combinations.

Limitations of Prior Work

Limitations of Prior Work: Textures generated directly by SDS suffer from low quality (oversmoothing, color oversaturation) and lack visual appeal.

Key Challenge

Key Challenge: The requirement of a disentangled digital avatar that is animatable, supports customizable outfits, possesses high-quality textures, and accommodates various clothing topologies (e.g., skirts vs. pants).

Method

Overall Architecture

A three-stage pipeline: (1) generation of the undergarment-clad body (based on SMPL-X + 2DGS); (2) sequential generation of clothing items (creating a mesh proxy followed by binding 2DGS to generate textures); (3) visually consistent texture refinement.

Key Designs

  1. GS-enhanced Mesh (GSM) Hybrid Representation:

    • Function: Binds 2D Gaussian Splatting onto mesh triangular faces.
    • Mechanism: Each 2DGS defines its position in the local coordinate system of its bound triangular face (barycentric coordinates \(\lambda_1, \lambda_2\) + normal offset \(z\)). During rendering, the world coordinates are \(\hat{\mu} = \lambda_1 x_A + \lambda_2 x_B + (1-\lambda_1-\lambda_2)x_C + z\vec{n}\). UV feature maps \((\mathcal{U}_c, \mathcal{U}_\alpha)\) are utilized to store color and opacity, facilitating ease of editing.
    • Design Motivation: Combines the physical simulation capabilities of meshes with the high-quality rendering of Gaussians, resulting in more realistic clothing motion and simplified texture editing.
  2. SAM-based Clothing Disentanglement and Filtering:

    • Function: Removes non-clothing Gaussians during the clothing generation process to achieve body-clothing disentanglement.
    • Mechanism: Allocates a category attribute \(o\) (0 = body, 1 = clothing) to each Gaussian. Precise semantic masks of dressed human images are obtained via SAM as labels to optimize \(o\) using MSE loss. Gaussians with \(o < 0.5\) are pruned every 500 iterations.
    • Design Motivation: SDS optimization inevitably generates parts of the body within clothing regions; semantic information provided by SAM assists in precise separation.
  3. Visually Consistent Texture Refinement:

    • Function: Improves the quality and multi-view consistency of SDS-generated textures.
    • Mechanism: Proposes a cross-view attention mechanism to maintain texture style consistency. An Incident Angle-Weighted Denoising Estimation (IAW-DE) strategy is designed to adjust the per-pixel denoising intensity based on the incident angle.
    • Design Motivation: Direct SDS optimization yields oversmoothed and multi-view inconsistent textures. The refinement stage utilizes the RFDS loss of Stable Diffusion 3 to improve quality.

Loss & Training

  • Body color branch: \(\mathcal{L}_{\mathcal{G}_b} = \mathcal{L}_{\text{rfds}}^{I_b} + \lambda_p \mathcal{L}_p + \lambda_s \mathcal{L}_s + \lambda_r \mathcal{L}_r\) (including position/scale/rotation regularization).
  • Clothing generation: \(\mathcal{L}_{\mathcal{G}_m} = \mathcal{L}_{\text{rfds}}^{I_a} + \mathcal{L}_{\text{sam}} + \lambda_{\text{dis}} \mathcal{L}_{\text{dis}} + \lambda_{\text{smooth}} \mathcal{L}_{\text{smooth}}\)
  • Distance regularization \(\mathcal{L}_{\text{dis}}\) constrains the distance from Gaussians to the mesh surface.
  • Smoothness regularization \(\mathcal{L}_{\text{smooth}}\) ensures a smooth clothing surface.
  • RFDS loss (adapted for rectified-flow models such as SD3) is used to replace traditional SDS.

Key Experimental Results

Main Results

Method Texture Quality Disentanglement Capability Outfit Customization Realistic Animation
TADA Moderate Limited
HumanGaussian Good Limited
TELA Moderate ✓(NeRF) Unrealistic
SO-SMPL Poor ✓(Limited) ✓(Limited) Limited
DAGSM Best Realistic

Ablation Study

Configuration Key Metrics Description
w/o SAM filtering Mixed body-clothing Boundaries cannot be clearly separated
w/ SAM filtering Clear separation Semantic guidance is effective
w/o Cross-view attention Multi-view texture inconsistency Caused by independent denoising in each view
w/ Cross-view attention Good consistency Cross-view feature sharing is effective
w/o IAW-DE Poor side texture quality Weak signal in regions with large incident angles
w/ IAW-DE Uniform high quality Weighting strategy compensates for side signals

Key Findings

  • GSM representation supports physical simulation-driven realistic clothing movement (e.g., natural hem flapping), which is far superior to traditional skeleton-driven methods.
  • Excellent texture diversity is demonstrated, supporting text-based descriptions of various clothing fabrics (lace, denim, wool, shear fabric).
  • Precise appearance control can be achieved by providing reference images.
  • Manual editing is supported by directly modifying UV texture maps.

Highlights & Insights

  • For the first time, text-driven fully disentangled digital human generation (body + multiple independent clothing items) is realized, where each garment can be replaced independently.
  • The GSM representation ingeniously integrates the advantages of meshes (structural representation, physical simulation) and Gaussians (rendering quality, complex textures).
  • The sequential generation design (body first, then clothing) is simple yet effective; generating clothing conditioned on the body naturally avoids interpenetration.
  • RFDS loss is utilized to replace SDS, leveraging the stronger priors of rectified-flow models such as SD3.

Limitations & Future Work

  • Clothing mesh extraction relies on the TSDF algorithm, which may lack precision for complex topologies.
  • Generation speed is limited by the multi-stage optimization process.
  • Physics-based simulation of clothing requires support from external simulators.
  • Handling occlusion relationships for multi-layer clothing (e.g., jacket + shirt) needs further validation.
  • SMPL-X → Human prior; 2DGS → High-quality surface reconstruction.
  • RFDS loss → Stronger distillation signal; SAM → Semantic segmentation assistance.
  • TELA → Pioneer of the disentanglement concept (though using NeRF restricted animation realism).

Rating

  • Novelty: ⭐⭐⭐⭐ The GSM hybrid representation is elegantly designed, and the disentangled generation pipeline is highly practical.
  • Experimental Thoroughness: ⭐⭐⭐⭐ A variety of generation results are presented, demonstrating support for outfit changes and animations.
  • Writing Quality: ⭐⭐⭐⭐ Detailed methodology description with clear overall illustrations.
  • Value: ⭐⭐⭐⭐⭐ Solves realistic pain points in virtual human generation; support for clothing customization and physical animation substantially boosts utility.