Efficient Volumetric Rendering of Dynamic Faces Using Meshed Radiance Manifolds

Kernekoncepter

A novel representation that enables high-quality volumetric rendering of dynamic facial performances with minimal compute and memory footprint, allowing for efficient playback on legacy graphics software without any neural network integration.

Resumé

The paper presents a novel representation for high-quality and memory-efficient volumetric rendering of dynamic facial performances in legacy renderers. The key ideas are:

1. Modeling the scene geometry using a set of static spatial manifolds of alpha values, and the temporal appearance changes as a time-conditioned UV-mapped radiance over these manifolds.
2. Decomposing the radiance into view-dependent and view-independent components, allowing for view-consistent rendering of the exported meshes.
3. Exporting the radiance manifolds as a single layered mesh for the entire sequence, and the corresponding view-independent UV-space appearance as RGBA texture maps, encoded as a video.
4. The exported representation can be rendered efficiently through simple alpha-blending of the textured mesh layers in any renderer, without requiring any neural network integration.
5. Experiments show the method achieves comparable visual quality to state-of-the-art neural rendering techniques, while providing significantly higher frame rates and lower memory/storage requirements.
6. The representation allows for graceful trade-offs between quality and efficiency through standard mesh decimation and texture downsampling operations.

Statistik

The paper reports the following key metrics:

PSNR: 25.49 ± 3.16
SSIM: 0.788 ± 0.069
LPIPS: 0.356 ± 0.038
VRAM usage: 602 MiB
Disk storage: 118 MiB
Rendering frame rate: >60 FPS

Citater

"Our method utilizes recent advances in neural rendering, particularly learning discrete radiance manifolds to sparsely sample the scene to model volumetric effects."
"We achieve efficient modeling by learning a single set of manifolds for the entire dynamic sequence, while implicitly modeling appearance changes as temporal canonical texture."
"We export a single layered mesh and view-independent RGBA texture video that is compatible with legacy graphics renderers without additional ML integration."

Vigtigste indsigter udtrukket fra

FaceFolds: Meshed Radiance Manifolds for Efficient Volumetric Rendering of Dynamic Faces

by Safa C. Medi... kl. arxiv.org 04-23-2024

https://arxiv.org/pdf/2404.13807.pdf

Dybere Forespørgsler

How could the method be extended to better capture view-dependent effects like specularities?

To better capture view-dependent effects like specularities, the method could be extended by incorporating additional information in the texture prediction process. Currently, the method focuses on learning view-independent radiance and transparency values, which limits its ability to render specularities accurately. By introducing a separate branch in the texture predictor to estimate specular or roughness maps based on the view-dependent component, the method could enhance its capability to render specular effects realistically. This would involve conditioning the texture prediction on the view direction to capture how light interacts with the surface based on the viewing angle, resulting in more accurate rendering of specular highlights and reflections.

What are the potential challenges in jointly learning the geometry and appearance models, and how could the training stability be further improved?

Jointly learning the geometry and appearance models in the context of radiance manifolds can present several challenges. One major challenge is ensuring that both models converge effectively during training, as discrepancies between the geometry and appearance predictions can lead to instability and poor rendering quality. To improve training stability, it is essential to carefully tune the relative learning rates of the two models and apply regularization techniques to prevent overfitting and promote consistency between the predictions. Additionally, incorporating more sophisticated regularization methods, such as adversarial training or consistency constraints, can help align the geometry and appearance models more effectively. Ensuring that the geometry predictions align with the appearance predictions across different frames and viewpoints is crucial for achieving high-quality rendering results.

How could the sampling and anti-aliasing techniques be enhanced to improve the overall visual quality and training efficiency of the method?

Enhancing the sampling and anti-aliasing techniques can significantly improve the overall visual quality and training efficiency of the method. One approach to enhance sampling is to implement adaptive sampling strategies that allocate more samples to regions with high detail or complex geometry, ensuring that important features are captured accurately. This adaptive sampling can help reduce aliasing artifacts and improve the fidelity of the rendered images. Additionally, incorporating advanced anti-aliasing techniques, such as multi-sample anti-aliasing (MSAA) or temporal anti-aliasing (TAA), can further reduce jagged edges and improve the smoothness of rendered images. These techniques can help mitigate aliasing artifacts and enhance the visual quality of the rendered results. Furthermore, optimizing the sampling process by leveraging efficient grid-based representations and combining them with anti-aliasing methods can improve training efficiency and accelerate convergence during the training process. By integrating these advanced sampling and anti-aliasing techniques, the method can achieve higher-quality rendering results with improved visual fidelity and training efficiency.