Blending Parametric Patches with Subdivision Surfaces

In this paper the problem of blending parametric surfacesusing subdivision patches is discussed. A new approach, namedremoving-boundary, is presented to generate piecewise-smooth subdivisionsurfaces through discarding the outmost quadrilaterals of the openmeshes derived by each subdivision step. Then the approach is employedboth to blend parametric bicubic B-spline surfaces and to fill n-sidedholes. It is easy to produce piecewise-smooth subdivision surfaces withboth convex and concave corners on the boundary, and limit surfaces areguaranteed to be C^2 continuous on the boundaries except for a fewsingular points by the removing-boundary approach. Thus the blendingmethod is very efficient and the blending surface generated is of goodeffect.