A Mesh Data Structure for Rendering and Subdivision

Abstract

Generating subdivision surfaces from polygonal meshes requires the complete topological information of the original mesh, in order to find the neighbouring faces, and vertices used in the subdivision computations. Normally, winged-edge type data-structures are used to maintain such information about a mesh. For rendering meshes, most of the topological information is irrelevant, and winged-edge type data-structures are inefficient due to their extensive use of dynamical data structures. A standard approach is the extraction of a rendering mesh from the winged-edge type data structure, thereby increasing the memory footprint significantly. We introduce a mesh data-structure that is efficient for both tasks: creating subdivision surfaces as well as fast rendering. The new data structure maintains full topological information in an efficient and easily accessible manner, with all information necessary for rendering optimally suited for current graphics hardware. This is possible by disallowing modifications of the mesh, once the topological information has been created. In order to avoid any inconveniences due to this limitation, we provide an API that makes it possible to stitch multiple meshes and access the topology of the resulting combined mesh as if it were a single mesh. This API makes the new mesh data structure also ideally suited for generating complex geometry using mesh-based L-systems.