  We present a simple yet effective method for skeleton-free motion
retargeting. Previous methods transfer motion between high-resolution meshes,
failing to preserve the inherent local-part motions in the mesh. Addressing
this issue, our proposed method learns the correspondence in a coarse-to-fine
fashion by integrating the retargeting process with a mesh-coarsening pipeline.
First, we propose a mesh-coarsening module that coarsens the mesh
representations for better motion transfer. This module improves the ability to
handle small-part motion and preserves the local motion interdependence between
neighboring mesh vertices. Furthermore, we leverage a hierarchical refinement
procedure to complement missing mesh details by gradually improving the
low-resolution mesh output with a higher-resolution one. We evaluate our method
on several well-known 3D character datasets, and it yields an average
improvement of 25% on point-wise mesh euclidean distance (PMD) against the
start-of-art method. Moreover, our qualitative results show that our method is
significantly helpful in preserving the moving consistency of different body
parts on the target character due to disentangling body-part structures and
mesh details in a hierarchical way.
