[NTG-context] Re: [metapost] shading in meta[post/play] & PDF

In metapost, "perfect" spheres can be drawn, like on http://www.gnu.org/software/3dldf/cdsmpls.html. But how can I add colour?

You could use the intersection points of the circles as the corners of rectangles and fill the latter. The more circles you use, the better the results will be. The very primitive surface hiding I've implemented will almost certainly fail, so you'll have to do this by hand or implement it yourself. You may be able to implement surface hiding and/or shading by operating on the MetaPost file generated by GNU 3DLDF, or by the PostScript file generated by MetaPost. Laurence