Coding topological structure of 3D CAD models

Abstract This paper proposes a loss-less method for encoding and compressing three-dimensional (3D) geometric models that may contain any combinations of wireframe, surface, and solid forms as well as various non-simple topological structure (e.g. cavities and strut edges) that could exist in 3D CAD models. Given a model, our method transforms it into a simple triangular mesh model by applying a sequence of Euler operators. Both the transformation process and the subdivided model are encoded and compressed to produce a compressed model. We implemented and evaluated our compression algorithm. Experiments with 3D models of mechanical parts showed that, in addition to being able to handle diverse and complex topological types, our method achieved excellent compression ratios.