With filters that is possible: http://www.w3.org/TR/SVG11/filters.html#AnExample (this path there could have any shape)
The only problem is that Inkscape doesn't support filters.
Terry Hancock wrote:
Gregory Novak wrote:
I'm trying to make a simple illustration that involves some three dimensional shapes (specifically prolate and oblate spheroids). I tried to do this ink Inkscape but found myself unable to make the gradients that seem to be required to show the 3D shape.
As has already been mentioned, you will find a real 3D graphics program like Blender is a much more powerful tool for creating 3D images. It does, of course, have a substantial learning curve.
Notice that the lines of constant color are not linear or elliptical, which is all I can seem to get from Inkscape gradients. I suppose I need to be able to create a path and say to the gradient tool "Make the lines of constant color follow this path."
Arbitrarily-shaped gradient effects can be achieved using the "blend" tool in Skencil ( http://skencil.org ). AFAIK, Inkscape does not yet have a tool like this.
It won't follow a path, though -- you'd create the inner and outer curves, then blend them.
Cheers, Terry