Wasn't it Barron Gillon who wrote:
>Does anyone know (preferably have a macro they could send me) how to find
>the surface normal of an isosurface at an arbitrary <x,y,z>?  If I remember
>correctly, a macro that returns <g'(x),h'(y),i'(z)> where f(x,y,z) =
><g(x),h(y),i(z)> and x, y, and z are specified will suffice.  The catch is
>of course that f() would be an arbitrary function, and I don't know how to
>find numeric derivatives.  Did I miss something in the standard includes
>that would do this?  Has anyone else done this?  Rune?  Thanks

Use trace().

-- 
Mike Williams
Gentleman of Leisure

Post a reply to this message