Photorealistic and Animatable Gaussian Splats for Real-Time Rendering of Dynamic Human Avatars

核心概念

A real-time approach for generating photorealistic renderings of animatable human avatars by representing the human as a collection of dynamic and motion-aware 3D Gaussian splats.

要約

The paper proposes ASH, a real-time method for high-quality rendering of animated humans, learned solely from multi-view videos. The key ideas are:

Animatable Gaussian Splats: ASH represents the dynamic character with 3D Gaussian splats, which are parameterized as texels in the texture space of a deformable template mesh. This allows modeling the mapping from skeletal motion to Gaussian splat parameters as an efficient 2D image-to-image translation task.

Motion-Aware Decoders: ASH employs two motion-aware 2D convolutional decoders to predict the geometry and appearance parameters of the Gaussian splats from the skeletal motion encoded in 2D texture maps. This enables real-time performance while capturing motion-dependent details.

Training Strategy: The paper proposes a carefully designed training paradigm, including a warmup stage to provide better initialization for the motion-aware decoders, which is crucial for handling the complex motion-dependent appearances in the training data.

The evaluations demonstrate that ASH significantly outperforms state-of-the-art real-time methods in rendering quality, while achieving comparable or even better results than offline methods, all while maintaining real-time performance.

統計

"Given a skeletal motion and a virtual camera view, ASH produces photorealistic renderings of clothed humans with motion-dependent details in real time."
"ASH only requires multi-view videos for supervision during training."

引用

"To this end, we propose ASH, a real-time approach for generating photorealistic renderings of animatable human avatars."
"Importantly, during training, ASH only requires multi-view videos for supervision."

抽出されたキーインサイト

ASH: Animatable Gaussian Splats for Efficient and Photoreal Human Rendering

by Haokai Pang,... 場所 arxiv.org 04-16-2024

https://arxiv.org/pdf/2312.05941.pdf

深掘り質問

How can the Gaussian splatting representation be further improved to better capture the detailed geometry and appearance of dynamic human characters?

To enhance the Gaussian splatting representation for dynamic human characters, several improvements can be considered:

Dynamic Gaussian Parameters: Instead of fixing the Gaussian parameters in the texture space, they could be dynamically updated based on the motion of the character. This would allow for more accurate representation of the changing geometry and appearance.
Adaptive Resolution: Implementing an adaptive resolution system where the texel density varies based on the complexity of the region being represented. This would ensure that areas with intricate details receive more texels for better fidelity.
Surface Deformation: Incorporating a mechanism to deform the Gaussian splats based on the underlying mesh deformation. This would enable the representation to better conform to the changing shape of the character.
Texture-based Normal Maps: Introducing normal maps in the texture space to capture finer details of the surface orientation, enhancing the realism of the rendered images.

What are the potential limitations of the current 2D texture-based approach, and how could a more direct 3D representation be explored while maintaining real-time performance?

The 2D texture-based approach has some limitations:

Loss of Depth Information: Representing 3D information in 2D textures may lead to a loss of depth cues, affecting the accuracy of the representation.
Limited Detail: The texel-based representation may not capture fine details and intricate geometry as effectively as a 3D representation.
Complex Deformations: Handling complex deformations and interactions in 2D texture space can be challenging.

To explore a more direct 3D representation while maintaining real-time performance, the following strategies could be considered:

Sparse 3D Voxel Grids: Utilizing a sparse 3D voxel grid representation to capture the geometry and appearance of the dynamic characters in 3D space efficiently.
Neural Implicit Functions: Leveraging neural implicit functions to directly model the 3D geometry and appearance of the characters, allowing for more accurate and detailed representations.
Hybrid Approaches: Combining 3D volumetric representations with 2D texture-based methods to benefit from the strengths of both approaches while mitigating their limitations.
Level of Detail Control: Implementing adaptive level of detail techniques to optimize computational resources and maintain real-time performance while preserving detail in the representation.

What other applications beyond human rendering could benefit from the animatable Gaussian splatting representation, and how could the method be adapted to those domains?

The animatable Gaussian splatting representation can be applied to various domains beyond human rendering, such as:

Object Animation: Animating and rendering dynamic objects with deformable surfaces, such as clothing, machinery parts, or natural elements like water and fire.
Virtual Environments: Creating interactive and dynamic virtual environments with realistic textures and deformable surfaces for gaming and simulation applications.
Medical Imaging: Modeling and visualizing dynamic biological structures, such as organs and tissues, for medical training and research purposes.
Architectural Visualization: Simulating and rendering dynamic architectural elements like fabric structures, moving parts, and environmental effects in real-time.

To adapt the method to these domains, specific considerations could include:

Customized Gaussian Parameters: Tailoring the Gaussian splat parameters to the specific characteristics and dynamics of the objects or environments being represented.
Domain-Specific Texture Mapping: Implementing texture mapping techniques that are optimized for the unique features of each application domain.
Real-Time Optimization: Developing efficient algorithms and data structures to ensure real-time performance while maintaining high-quality rendering.
Interaction and Physics Simulation: Integrating interactive elements and physics simulations to enhance the realism and interactivity of the rendered scenes.