Cylindrical Surface Pasting

Abstract

The idea of hierarchical modeling is that many surfaces have different levels of detail and for modeling purposes it is useful to interactively edit these surfaces at any level of detail. Detail can be added to tensor-product B-spline via knot insertion, but once the detail has been added the the surface can not be edited at a lower level of detail. Hierarchical B-splines were designed to allow for a type of knot insertion method that still admits editing the surface at any level of detail. However, the details can not be rotated, nor is it convenient to create a library of such details. Surface pasting is a generalization of hierarchical B-splines that allows for the creation of a feature library, and where the pasted features can be rotated and scaled, and translated across the base surface.

Cylindrical pasting is a parametric-blending method that creates a smooth transition surface between a pair of B-spline surfaces that do not originally intersect. This blending surface is a deformed cylinder, and its creation is based on the surface pasting composition method, which adds detailed features to base surfaces by means of an efficient displacement method. In cylindrical pasting, a transition cylinder can be pasted on a NUBS surface or onto a NUBS cylinder. A displacement scheme is used to locate the control points of the blending cylinder to achieve approximate $C^1$ continuity between the boundaries of the base surfaces and the edges of the cylinders.

The Paper

Compressed PostScript, 1466kB

Bibliography Entry

@techreport{mann-yeung-99,
    author = "S. Mann and T. Yeung",
    title = "Cylindrical Surface Pasting",
    year = "1999",
    school = "University of Waterloo",
    address = "Waterloo, Ontario, Canada N2L 3G1",
    note = "Available on WWW as
           mbox{ftp://cs-archive.uwaterloo.ca/cs-archive/CS-99-13/}"
}