Progressive Gap Closing for MeshRepairing

Abstract

Modern 3D acquisition and modeling tools generate high-quality, detailed geometric models. However, in order to cope with the associated complexity, several mesh decimation methods have been developed in the recent years. On the other hand, a common problem of geometric modeling tools is the generation of consistent three-dimensional meshes. Most of these programs output meshes containing degenerate faces, T-vertices, narrow gaps and cracks. Applying well-established decimation methods to such meshes results in severe artifacts due to lack of consistent connectivity information. The industrial relevance of this problem is emphasized by the fact that as an output of most of the commercial CAD/CAM and other modeling tools, the user usually gets consistent meshes only for separate polygonal patches as opposed to the whole mesh. In this paper we propose a solution, which interprets the above issue as a mesh boundary decimation task. As suggested by Garland and Heckbert 4 and Popović and Hoppe 12, adding a vertex pair contraction operation enables to join unconnected regions of the mesh. In addition to this and the usual edge-collapse operation, we introduce a new vertex-edge collapse operation. This provides extra support for closing gaps and stitching together the boundaries of triangle patches lying in near proximity to each other. In our method, the decimation process is error controlled and conducted in a progressive manner in terms of the error. Therefore, the user is enabled to visually inspect and interactively influence the procedure.