Adaptive Implicit Modeling using Subdivision Curves and Surfaces as Skeletons

Alexis Angelidis (1) , Marie-Paule Cani (1)

1 iMAGIS - Models, Algorithms and Geometry for Computer Generated Image Graphics

Recent work has shown that implicit modeling using levels of details (LODs) is possible thanks to the use of subdivision- curves as skeletons. However, the geometric skeleton of a 3D shape is, in the general case, a graph of interconnected curve segments and surface patches, the exclusive use of curve skeletons is therefore not sucient. We present a model that uses a graph of interconnected subdivision curves and surfaces as a skeleton, on which a varying radius can be specied in order to control surface thickness. The subdivision levels of the skeleton provide levels of detail for the eld function that denes the implicit surface. Its visualization is achieved by generating a coarse mesh that surrounds the skeleton. At high valence skeleton ver- tices, triangulation topology issues are managed by locally overlapping the iso-surface triangulations. The mesh is then adaptively rened in order to sample the current LOD of the implicit surface within an error tolerance. The last contribution is a new solution to the unwanted blending problem. It avoids blending between parts of the surface that do not correspond to neighboring skeletal el- ements, and ensures C1 continuity everywhere. All these methods are integrated into an interactive modeling system, where the user can create, view and edit complex shapes at dierent levels of detail.

Domaines: Synthèse d'image et réalité virtuelle [cs.GR]

Alexis Angelidis, Marie-Paule Cani. Adaptive Implicit Modeling using Subdivision Curves and Surfaces as Skeletons. The seventhSymposium on Solid Modeling and Applications (SMA'02), ACM, Jun 2002, Saarbrücken, Germany. pp.45 - 52, ⟨10.1145/566282.566292⟩. ⟨inria-00537494⟩