abstine@polymer.che.clarkson.edu (Art Stine) (10/26/90)
Does anyone have an algorithm or maybe even some code which will take a set of points in 3d and basically 'shrink-wrap' them (ie, form a volume from them by connecting all the 'outside' points) thanks much art stine sr network engineer clarkson u abstine@polymer.che.clarkson.edu
landheim@bbn.com (Greg Landheim) (10/27/90)
In article <9010252023.AA02947@polymer.che.clarkson.edu> abstine@polymer.che.clarkson.edu (Art Stine) writes: >Does anyone have an algorithm or maybe even some code which will >take a set of points in 3d and basically 'shrink-wrap' them (ie, form >a volume from them by connecting all the 'outside' points) > This won't answer your question directly, but I don't have a reference at my elbow answering your specific question. "Programs for Generating Extreme Vertices and Centroids of Linearly Constrained Experimental Regions," Gregory F. Piepel, Journal of Quality Technology, Vol. 20, No. 2, April 1988, describes (and lists) FORTRAN source for finding the extreme vertices (which is what I assume you mean by 'outside' points) for 3 and arbitrarily higher dimensions, based on linear constraits. Greg Landheim
jroth@allvax.enet.dec.com (Jim Roth) (10/31/90)
In article <9010252023.AA02947@polymer.che.clarkson.edu>, abstine@polymer.che.clarkson.edu (Art Stine) writes... >Does anyone have an algorithm or maybe even some code which will >take a set of points in 3d and basically 'shrink-wrap' them (ie, form >a volume from them by connecting all the 'outside' points) There is a recent ACM TOG paper: A. M. Day The implementation of an algorithm to find the convex hull of a set of three-dimensional points ACM TOG Vol 9 No 1, Jan 1990, pp 105-132 Includes Pascal code. It is based on the well-known Preparata-Hong algorithm, with due care to handle the annoying degenerate cases that can arise. - Jim