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Multi-resolution
Surface
Approximation for
Animation
David
Forsey and
Lifeng
Wang
Appeared in Graphics Interface '93 (pp. 192-200; Toronto, Ontario)
TR-92-36
ABSTRACT
This paper considers the problem of approximating a digitized surface in R3
with a hierarchical bicubic B-spline to produce a manipulatable surface for
further modeling or animation. The 3D data's original mapping from R3
(multiple rows of cylindrical scans) is mapped into the parametric domain of
the B-splice (also in R3) using a modified chord-length parameterization. This
mapping is used to produce a gridded sampling of the surface, and a modified
full multi-grid (FMG) technique is employed to obtain a high-resolution
B-spline approximation. The intermediate results of the FMG calculations
generate the component overlays of a hierarchical spline surface
reconstruction.
Storage requirements of the hierarchical representation are reduced by
eliminating offsets wherever their removal will not increase the error in the
approximation by more than a given amount. The resulting hierarchical spline
surface is interactively modifiable (modulo the size of the dataset and
computing power) using the editing capabilities of the hierarchical surface
representation allowing either local or global changes to surface shape while
retaining details of the scanned data.