Despite much progress, creating real-time high-fidelity head avatar is still
difficult and existing methods have to trade-off between speed and quality.
3DMM based methods often fail to model non-facial structures such as eyeglasses
and hairstyles, while neural implicit models suffer from deformation
inflexibility and rendering inefficiency.
Although 3D Gaussian has been demonstrated to possess promising capability
for geometry representation and radiance field reconstruction, applying 3D
Gaussian in head avatar creation remains a major challenge since it is
difficult for 3D Gaussian to model the head shape variations caused by changing
poses and expressions. In this paper, we introduce PSAvatar, a novel framework
for animatable head avatar creation that utilizes discrete geometric primitive
to create a parametric morphable shape model and employs 3D Gaussian for fine
detail representation and high fidelity rendering. The parametric morphable
shape model is a Point-based Morphable Shape Model (PMSM) which uses points
instead of meshes for 3D representation to achieve enhanced representation
flexibility. The PMSM first converts the FLAME mesh to points by sampling on
the surfaces as well as off the meshes to enable the reconstruction of not only
surface-like structures but also complex geometries such as eyeglasses and
hairstyles. By aligning these points with the head shape in an
analysis-by-synthesis manner, the PMSM makes it possible to utilize 3D Gaussian
for fine detail representation and appearance modeling, thus enabling the
creation of high-fidelity avatars. We show that PSAvatar can reconstruct
high-fidelity head avatars of a variety of subjects and the avatars can be
animated in real-time ($\ge$ 25 fps at a resolution of 512 x 512 )

介绍了一种利用离散几何基元创建参数化可变形形状模型，并利用三维高斯进行细节表示和高保真渲染的新型框架 PSAvatar，能够重建各种对象的高保真头像，实现实时动画效果（分辨率为 512 x 512，帧率≥25fps）。