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Siggraph Course Mesh Parameterization: Theory and Practice Barycentric Mappings
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Triangle Mesh Parameterization triangle mesh – vertices – triangles parameter mesh – parameter points – parameter triangles parameterization – piecewise linear map
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The Spring Model replace edges by springs fix boundary vertices relaxation process energy of spring between and : – spring constant – spring length total energy
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Energy Minimization interior vertices ’s neighbours overall spring energy partial derivative
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Energy Minimization minimum of spring energy for all interior points is a convex combination of its neighbors with weights
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The Linear System separation of variables unknown parameter points fixed linear system
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The Linear System solve system twice for and coordinates of interior parameter points matrix is – sparse – diagonally dominant – nonsingular as long as all
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Choice of Weights uniform spring constants –, chordal spring constants –, no fold-overs for convex boundary no linear reproduction – planar meshes are distorted
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Choice of Weights suppose is a planar mesh specify weights such that barycentric coordinates of then solving reproduces
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Barycentric Coordinates Wachspress coordinates discrete harmonic coordinates mean value coordinates normalization
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fold-overs for negative coordinates – affine combinations, numerically unstable if mean value coordinates guaranteed to be positive Example – Pyramid Wachspressdiscrete harmonicmean value
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The Boundary Mapping chordal parameterization around convex shape – circle – rectangle projection into least squares plane – may lead to fold-overs
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