Surface fitting is problematic because a unique parametric coordinate should be assigned to each geometric data point, and the precision of the fit is quite sensitive to the distribution of these parametric coordinates.
Direct parametric surface fitting requires that we first assign a unique parametric coordinate to each of the N vertices of V(x,y,z).
[??] = ([N.sub.bx] + 2) x ([N.sub.by] + 2) such that the distance between the geometric data points and points on the surface with the same parametric coordinate is minimized.
Then a parametric surface is fitted to the projected geometric data points, whose operation also assigns a unique parametric coordinate to each data point.
We elect to use dimension 3 (3 physical coordinates) and codimension 2 (2 parametric coordinates) parametric B-splines.
Version 4.0 users can create color 3-D surfaces mesh plots, contour plots, scatterplots, data trajectories, and images using rectangular, spherical, and general parametric coordinate