CTAN has a new package: m3D
m3D is just another extension of plain MetaPost for 3 dimensional graphics. It may change in the future and so does not claim to be stable. But one can make already funny things with it. The best documentation is obtained by reading the file m3Dplain. One may get some ideas for designing is own 3D package, or for any other MetaPost task.
See this package at http://tug.ctan.org/tex-archive/graphics/metapost/contrib/macros/m3D . You may get a better network connection by using a CTAN mirror near to you; see http://tug.ctan.org/tex-archive/README.mirrors . Our service is supported by the TeX Users Group http://www.tug.org . Please join a users group; see http://www.tug.org/usergroups.html .
m3D – Extension of plain METAPOST for 3D graphics
M3D is another extension of plain METAPOST for 3 dimensional graphics. While the author claims it should not be regarded as stable, he believes it has value simply as a source of ideas for those who wish to implement 3D graphics in METAPOST.
The package (stable or not) exhibits some interesting abilities, both in the package manual and in the gallery that comes with the distribution.