There's a wonderful tutorial on drawing 3D graphics in PostScript on http://www.math.ubc.ca/~cass/graphics/manual/, specifically http://www.math.ubc.ca/~cass/graphics/manual/code/doughnut.eps as an example. And there's a detailed description on shading in PostScript in http://partners.adobe.com/public/developer/en/ps/PLRM.pdf, page 259 (I attached an example and have some more on computer if anyone is interested; I downloaded them from Adobe, but don't know the URL any more) or on shading in PDF in http://partners.adobe.com/public/developer/en/pdf/PDFReference16.pdf, page 272. (They're basically the same.) In metapost, "perfect" spheres can be drawn, like on http://www.gnu.org/software/3dldf/cdsmpls.html. But how can I add colour? Even if it would be too tricky to add colour and proper shading on the sphere - Is there any possibility to use advanced shading techiques described in PLRM inside metapost/metaplay for the most simple cases, say, like in the attached example? Metaplay allows circular and gradient shading and no others. I don't mind if I had to hard-code the shading. PSTricks allows some more advanced shading techniques and even direct PostScript code integration (with \special I think). Is anything similar possible in metapost/play? The spheres drawn directly in PostScript as in the examples above still have straight lines (well, I agree that with some mathematics it would be possible to draw them with proper splines as well). Thanks for all the suggestions, Mojca