Quasi-regular surface representation

Automatically generated or laser-scanned surfaces often exhibit large clusters with a uniform pattern. To take advantage of the regularity within clusters, a two-level mesh data structure (called Qreg) was proposed and implemented. Extending patch-based structures, Qreg uses a spiral enumeration scheme and an adjustable connectivity stencil to support efficient pointer-less access within each cluster as well as easy access across cluster boundaries. Attributes are generic and user-definable; and are allocated according to the index order of the spiral enumeration. Qreg also supports novel properties: multi-sided clusters, T-corners between the clusters, cluster joining and splitting, and adaptive as well as LOD refinement.; An algorithmic framework was proposed to support surface modeling in programmable graphics hardware. The framework uses a patch-based mesh data structure that is similar to Qreg. A future graphics processor unit (GPU), enhanced with random read and write to video memory, was shown to be able to represent, refine and adjust complex meshes arising in modeling, simulation and animation. To leverage SIMD parallelism, a general model based on the mesh atlas is developed and a particular implementation without adjacency pointers was proposed in which primal, binary refinement of (possibly mixed) quadrilateral and triangular meshes of arbitrary topological genus, as well as their traversal is supported by user-transparent programmable graphics hardware. Adjustment, such as subdivision smoothing rules, is realized via user-programmable mesh shader routines. Attributes are defined in the graphics application by binding them to one of several addressing mechanisms.