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Nonobtuse Remeshing and Mesh Decimation. John Y.S. Li and Richard (Hao) Zhang GrUVi lab, Simon Fraser University, Canada. Nonobtuse Remeshing and Mesh Decimation. SGP 2006 Cagliari, Italy. Introduction. I changed spacing. Goal Nonobtuse = at most 90 o Motivation Delaunay Triangulation
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Nonobtuse Remeshing and Mesh Decimation John Y.S. Li and Richard (Hao) Zhang GrUVi lab, Simon Fraser University, Canada
Nonobtuse Remeshing and Mesh Decimation SGP 2006 Cagliari, Italy Introduction I changed spacing • Goal • Nonobtuse = at most 90o • Motivation • Delaunay Triangulation • Finite Element Method • Geodesic Computation • Planar Mesh Embedding
Nonobtuse Remeshing and Mesh Decimation SGP 2006 Cagliari, Italy Related work • Open problem. [GY03]– a bit misleading • Nonobtuse triangulation of polygons. [BMR94] • 30o - 120o angle bound. [Che93] • Minimum 30o angle bound. [CS05] • 3D domain tiling with acute tetrahedra. [ESU04]
Nonobtuse Remeshing and Mesh Decimation SGP 2006 Cagliari, Italy Overview of our Approach 1 2 3 Generate initial nonobtuse mesh Deform-to-fit optimization Nonobtuse decimation Generality and flexibility of our framework to allow … ??? I think this is quite important.
Nonobtuse Remeshing and Mesh Decimation SGP 2006 Cagliari, Italy Modified Marching Cubes 1 Input is mesh and convert to SDF? • Input: Signed distance field • Based on midpoint-based Marching Cubes (MC) • Some new vertices are inserted inside the cubes • Guaranteed nonobtusity • No angles less than 30o • Handling open mesh is a bit tricky, but possible
Nonobtuse Remeshing and Mesh Decimation SGP 2006 Cagliari, Italy Optimization 2 Clearly separate error reduction and smoothing • Objective • Quadric term • Associate closest triangle T to v • Average squared distances • Smoothing: • Better angle quality Mark T, v, etc. below
Nonobtuse Remeshing and Mesh Decimation SGP 2006 Cagliari, Italy Optimization 2 • Constraints • feasible region of an edge • feasible region of a vertex
Nonobtuse Remeshing and Mesh Decimation SGP 2006 Cagliari, Italy Optimization 2 • Quadratic Programming • Iterative optimization • Priority Queue • Updating quadrics • Local search of closest triangle T to v ― a heuristic • Stopping condition • Smoothing You need to elaborate a bit on this slide. Indicate alternating between …
Nonobtuse Remeshing and Mesh Decimation SGP 2006 Cagliari, Italy Nonobtuse Decimation 3 • Similar framework for nonobtuse edge collapse • Optimal location for the unified vertex • Cost of edge collapse • Updating quadrics If you are short on time, this slide can be simplified. The framework is quite standard.
Nonobtuse Remeshing and Mesh Decimation SGP 2006 Cagliari, Italy Results • Different sampling grids in Modified MC
Nonobtuse Remeshing and Mesh Decimation SGP 2006 Cagliari, Italy Results • Effects of smoothness term and smoothing
Nonobtuse Remeshing and Mesh Decimation SGP 2006 Cagliari, Italy Results No slide on speed? • Angle distribution
Nonobtuse Remeshing and Mesh Decimation SGP 2006 Cagliari, Italy Future work Improving speed? • Better angle bound • Recently achieved 30o – 90o bound • Nonobtuse meshing from point cloud • Handling meshes with boundaries • Feature preservation • Guaranteed acute remeshing
Thank you! Any questions?