Automatic generation of structure preserving models for computer-aided geometric design

Abstract

The computer-aided design (CAD) of various products, machines and details, virtual movie heroes and video game characters is a computer science area with significant practical implications and challenging open scientific problems. One of these open problems is the automatic generation of 3D geometric designs of existing physical objects, a process widely known as reverse engineering. The manual reverse engineering of a geometric design typically incurs costs comparable to engineering a completely new design from scratch. Therefore, the CAD industry is very interested in algorithmic solutions which generate such designs automatically or with a minimal user guidance. In this thesis we describe a set of techniques which combined deliver a solution for reverse engineering physical objects, which surface geometry is represented by dense triangle meshes. We contribute several novel algorithms and new research results in the following geometry processing areas: polygonal mesh simplification, anisotropic and quad-dominant remeshing, scattered data approximation, multiresolution mesh editing. The output of our system is a piecewise smooth Catmull-Clark subdivision surface representing the original object. Its control mesh provides the available degrees of freedom to manipulate and edit the shape of the represented object. Since our algorithms are designed to produce high quality control meshes, aligned to the structure and the features of the input shape, the output surface representation can be used in various mainstream computer graphics applications such as CAD systems, computer-simulated physical processes and animations (movies and games)