StructLDM: Structured Latent Diffusion for 3D Human Generation

StructLDM: Enhancing 3D Human Generation with Structured Latent Diffusion Models

Introduction

The evolution of 3D human generative models has ushered in an era where the boundary between digital and physical realities continues to blur. Despite significant advancements, traditional methods have primarily relied upon compact 1D latent spaces for modeling, which inherently neglect the complex, articulated structure and semantic richness of human anatomy. This paper introduces StructLDM, a novel approach leveraging structured latent diffusion models for generating 3D humans. StructLDM transcends traditional limitations by utilizing a high-dimensional, semantic structured latent space learned from 2D images, offering unprecedented control and fidelity in 3D human generation.

Challenges in Current 3D Human Modeling Techniques

Existing 3D human generative models, despite their progress, face significant hurdles:

• They often oversimplify the human body's intricate structure, opting for a compact 1D latent space that limits control and expressiveness.
• The generative quality, particularly for complex entities like humans, remains suboptimal when compared to simpler subjects such as faces or objects, indicating a need for more robust modeling methods.

StructLDM: Key Innovations and Design

StructLDM introduces three critical innovations to address these challenges:

1. Semantic Structured Latent Space: By defining a latent space on the dense surface manifold of a statistical human body template, StructLDM captures the articulated nature of the human body, allowing for detailed appearance capture and editing.
2. Structured 3D-Aware Auto-Decoder: This architecture factorizes the global latent space into body parts represented by conditional structured local Neural Radiance Fields (NeRFs). Such an arrangement enables the rendering of view-consistent humans under various poses and clothing styles.
3. Structured Latent Diffusion Model: For generative human appearance sampling, StructLDM employs a novel diffusion process tailored with structure-specific normalization, facilitating control over 3D human generation and editing tasks.

Demonstrated Capabilities and Applications

StructLDM not only advances the state-of-the-art in 3D human generation but also unlocks new potentials for high-level manipulations such as:

• Pose, view, and shape control for dynamic rendering of digital humans.
• Compositional generations and part-aware editing without the need for explicit clothing masks.
• Virtual try-on applications, allowing for realistic simulations of clothing on digital avatars.

Empirical Validation and Performance

Extensive experiments across multiple datasets (UBCFashion, RenderPeople, and THUman2.0) confirmed StructLDM's superior generative performance. Notably, it demonstrated remarkable proficiency in rendering high-quality, view-consistent digital humans with diverse appearances and in various poses. StructLDM significantly outperformed existing state-of-the-art models in terms of FID scores, highlighting its advanced generative capabilities and the effectiveness of structured latent diffusion in modeling complex 3D human figures.

Theoretical Implications and Future Directions

StructLDM's innovative use of structured latent spaces and diffusion models for 3D human generation represents a significant theoretical advancement. It highlights the importance of considering the intricate structure and semantics of human anatomy in generative modeling. Looking forward, the framework's ability to precisely control and manipulate digital human representations paves the way for future exploration in virtual and augmented reality applications, advanced animation techniques, and the development of more immersive digital experiences.

Conclusion

In summary, StructLDM sets a new benchmark for 3D human generation by effectively leveraging structured latent spaces and diffusion models. Its unique approach not only addresses the inherent limitations of previous methods but also opens up new avenues for exploration and application in the digital creation of human figures. As this field continues to evolve, StructLDM's contributions will undoubtedly serve as a foundational framework for future advancements in 3D human modeling.