Project: Skeleton Extraction by Mesh Contraction

Extraction of curve-skeletons is a fundamental problem with many applications in computer graphics and visualization. In this paper, we present a simple and robust skeleton extraction method based on mesh contraction. The method works directly on the mesh domain, without pre-sampling the mesh model into a volumetric representation. The method first contracts the mesh geometry into a zero-volume skeletal shape by applying implicit Laplacian smoothing with global positional constraints. The contraction does not alter the mesh connectivity and retains the key features of the original mesh. The contracted mesh is then converted into a 1D curve-skeleton through a connectivity surgery process to remove all the collapsed faces while preserving the shape of the contracted mesh and the original topology. The centeredness of the skeleton is refined by exploiting the induced skeleton-mesh mapping. The contraction process generates valuable information about the object's geometry, in particular, the skeleton-vertex correspondence and the local thickness, which are useful for various applications. We demonstrate its effectiveness in mesh segmentation and skinning animation.

Skeleton Extraction by Mesh Contraction ACM Transaction on Graphics (Proceedings of SIGGRAPH 2008) Oscar Kin-Chung Au¹ Chiew-Lan Tai¹ Hung-Kuo Chu² Daniel Cohen-Or³ Tong-Yee Lee² Hong Kong University of Science &Technology²National Cheng Kung University ³Tel Aviv University
Teaser: Our method extracts a 1D skeletal shape by performing geometry contraction using constrained Laplacian smoothing. Left to right are the original mesh and the results of the contraction after 1, 2 and 3 iterations. Faces with zero area are drawn in red. The ray-traced image shows the final skeleton after performing connectivity surgery and embedding refinement.
Abstract	Extraction of curve-skeletons is a fundamental problem with many applications in computer graphics and visualization. In this paper, we present a simple and robust skeleton extraction method based on mesh contraction. The method works directly on the mesh domain, without pre-sampling the mesh model into a volumetric representation. The method first contracts the mesh geometry into a zero-volume skeletal shape by applying implicit Laplacian smoothing with global positional constraints. The contraction does not alter the mesh connectivity and retains the key features of the original mesh. The contracted mesh is then converted into a 1D curve-skeleton through a connectivity surgery process to remove all the collapsed faces while preserving the shape of the contracted mesh and the original topology. The centeredness of the skeleton is refined by exploiting the induced skeleton-mesh mapping. The contraction process generates valuable information about the object's geometry, in particular, the skeleton-vertex correspondence and the local thickness, which are useful for various applications. We demonstrate its effectiveness in mesh segmentation and skinning animation.
Paper
Video	Skeleton Extraction (~46MB)
Demo Program	zipped executable code with models
Examples
BibTeX	@ARTICLE{Au:2008, author = {Oscar Kin-Chung Au and Chiew-Lan Tai and Hung-Kuo Chu and Daniel Cohen-Or and Tong-Yee Lee}, title = {Skeleton Extraction by Mesh Contraction}, journal = {ACM Trans. Graph.}, year = {2008}, volume = {27}, number = {3}, }