3D Gaussian Head Avatars with Expressive Dynamic Appearances by Compact Tensorial Representations

Recent studies have combined 3D Gaussian and 3D Morphable Models (3DMM) to construct high-quality 3D head avatars. In this line of research, existing methods either fail to capture the dynamic textures or incur significant overhead in terms of runtime speed or storage space. To this end, we propose a novel method that addresses all the aforementioned demands. In specific, we introduce an expressive and compact representation that encodes texture-related attributes of the 3D Gaussians in the tensorial format. We store appearance of neutral expression in static tri-planes, and represents dynamic texture details for different expressions using lightweight 1D feature lines, which are then decoded into opacity offset relative to the neutral face. We further propose adaptive truncated opacity penalty and class-balanced sampling to improve generalization across different expressions. Experiments show this design enables accurate face dynamic details capturing while maintains real-time rendering and significantly reduces storage costs, thus broadening the applicability to more scenarios.

Our goal is to reconstruct 3DGS head avatar with dynamic details, ensuring real-time rendering and minimized storage. We use a parametric face mesh to describe large-scale geometry motions, moving the bound Gaussian splats accordingly. A triplane stores view-dependent appearance in canonical space, while 1D feature lines are used for dynamic details per blendshape, allowing interpolation with expression coefficients. Finally, the geometry attributes of the splats, along with the canonical appearance and dynamic details, are combined to render the face image.