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In this paper, we present a multigrid technique for
efficiently deforming large surface and volume meshes. We show that a
previous least-squares formulation for distortion minimization reduces
to a
Laplacian system on a general graph structure for which we derive an
analytic expression. We then describe an efficient multigrid algorithm
for solving the relevant equations. Here we develop novel
prolongation and restriction operators used in the multigrid cycles.
Combined with a simple but effective graph coarsening strategy, our
multigrid algorithm outperforms other direct and multigrid solvers
in both time and memory cost. While direct factorization methods have
frequently been applied to related problems, it is demonstrated that
even for modestly sized meshes, our multigrid solver surpasses the most
sophisticated factorization codes. Moreover, since our multigrid solver
does not rely on extensive precomputation, it is particularly well
suited for integration with a general mesh editing
environment where unpredictable combinations of different operations
will invalidate the results of any such precomputation. Experimental
evidence of these advantages is provided on a number of meshes with a
wide range of size.
Lin Shi, Yizhou Yu, Nathan Bell and Wei-Wen Feng
SIGGRAPH 2006 (ACM Transactions on Graphics, Vol. 24, No. 3, 2006), To appear
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