document: Blending parametric patches with subdivision surfaces In this paper the problem of blending parametric surfaces using subdivision patches is discussed . A new approach , named removing-boundary , is presented to generate piecewise-smooth subdivision surfaces through discarding the outmost quadrilaterals of the open meshes derived by each subdivision step . Then the approach is employed both to blend parametric bicubic B-spline surfaces and to fill n-sided holes . It is easy to produce piecewise-smooth subdivision surfaces with both convex and concave corners on the boundary , and limit surfaces are guaranteed to be C/sup 2 / continuous on the boundaries except for a few singular points by the removing-boundary approach . Thus the blending method is very efficient and the blending surface generated is of good effect
doc_bio_tags: O O O O B I O O O O O O O O O O B I O O O O O O O O O O O O O O O B I O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O
extractive_keyphrases: subdivision surfaces subdivision patches quadrilaterals
abstractive_keyphrases: parametric surfaces blending piecewise-smooth subdivision surfaces parametric bicubic b-spline surfaces piecewise smooth subdivision surfaces