High-fidelity human 3D models can now be learned directly from videos,
typically by combining a template-based surface model with neural
representations. However, obtaining a template surface requires expensive
multi-view capture systems, laser scans, or strictly controlled conditions.
Previous methods avoid using a template but rely on a costly or ill-posed
mapping from observation to canonical space. We propose a hybrid point-based
representation for reconstructing animatable characters that does not require
an explicit surface model, while being generalizable to novel poses. For a
given video, our method automatically produces an explicit set of 3D points
representing approximate canonical geometry, and learns an articulated
deformation model that produces pose-dependent point transformations. The
points serve both as a scaffold for high-frequency neural features and an
anchor for efficiently mapping between observation and canonical space. We
demonstrate on established benchmarks that our representation overcomes
limitations of prior work operating in either canonical or in observation
space. Moreover, our automatic point extraction approach enables learning
models of human and animal characters alike, matching the performance of the
methods using rigged surface templates despite being more general. Project
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本文提出一种新的混合点表示方法，通过自动产生的几何数据点集作为支架和简便的映射方法，学习人形和动物角色的可动形变模型，相较于之前的方法，该方法无需昂贵的采集设备或受控环境的条件，且更具普适性和可推广性。