a) (b) (c) (d) Figure 1: A skeleton-driven mesh deformation. (a) A dragon model (100K triangles), its skeletal mesh (6K triangles), and control points used to produce a global deformation of the skeletal mesh. (b) A free-form deformation of the skeletal mesh. (c) Reconstruction of an approximate dragon model (6K triangles), from the deformed skeleton. (d): The final deformation is obtained by applying DSS [18] to the approximate dragon model; coloring by mean curvature is used for a quality

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... uation of the deformed mesh. ABSTRACT In this paper, we propose a new scheme for free-form skeletondriven global mesh deformations. First a Voronoi-based skeletal mesh is extracted from a given original mesh. Next the skeletal mesh is modified by free-form deformations. Then a desired global shape deformation is obtained by reconstructing the shape corresponding to the deformed skeletal mesh. We develop a mesh fairing procedure allowing us to avoid possible global and local selfintersections of the reconstructed mesh. Finally, using a displaced subdivision surface representation [18] improves the speed and robustness of our approach. Multiresolution mesh representations [26, 17, 14, 16, 18] are often used for modeling global natural-looking shape deformations. Recently skeleton-driven global free-form shape deformations drew much attention [19, 21, 7, 6] because they are well-suited for largescale shape deformations and, therefore, can be used in numerous applications in the computer game industry. In this paper, we develop a new scheme for free-form skeletondriven global shape deformations. Given a triangle mesh approximating 3D shape, first we build a Voronoi-based skeletal mesh. The skeletal mesh inherits the connectivity of the original mesh and there is one-to-one correspondence between the vertices of the original and skeletal meshes. We use mesh evolutions in order to improve the skeletal mesh. The original mesh is then represented as the set of displacements applied to the vertices of the improved (smoothed) skeletal mesh. The mesh deformation process is combined from deformations of the smoothed skeletal mesh and the displacement field. We also use mesh evolutions to remove local and global self-intersections of the deformed mesh. Finally, since our shape representation resembles the displaced subdivision surfaces [18], we enrich our mesh deformation approach by a multiscale technique. Fig. 1 above gives some impression on how our approach works. The basic (and very simple) idea of our skeleton-based approach to global shape deformations is sketched in Fig. 2 . Extract Skeleton Edit Skeleton Update Original Geometry Figure 2: Skeleton-based shape deformation.