[comp.graphics] Tangents to rational B-spline curves/surfaces

cmm@creare.UUCP (Chris Morley) (01/09/90)

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?