Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!snorkelwacker!bloom-beacon!bu.edu!bu-cs!dartvax!creare!cmm
From: cmm@creare.UUCP (Chris Morley)
Newsgroups: comp.graphics
Subject: Tangents to rational B-spline curves/surfaces
Message-ID: <1155@creare.UUCP>
Date: 8 Jan 90 21:43:49 GMT
Distribution: na
Organization: Creare Inc., Hanover, NH
Lines: 12

Hi -
	I'm implementing a solid modelling system using non-uniform
rational b-splines, and need to take derivatives of these curves &
surfaces for various reasons. The straight forward approach of applying
the quotient rule to the definition of rational curves produces a
pretty horrible result - does anyone know of faster/easier algorithms
to do this? Thanks for any help you can offer -

Chris Morley
...dartvax!creare!cmm

ps - is anyone else out there using nurbs for anything interesting?