The movie15 package (an interface to embed movies, sounds and 3D objects into PDF documents for use with LaTeX as well as pdfLaTeX) requires 3D files to be in u3d format for embedding into pdf. This works fine with the sample files provided, and I have no problem generating suitable 3D files, but so far, I have not found a way to convert them to u3d. MeshLab, usually the first place to go for such things, crashes during u3d export.
Does anyone know of a way to produce u3d files suitable for use with the movie15 package?
As I am a newbie, I can only post one link, so I put a version of this question with some links on my blog.
(Links added in edit)
Edit: I have to add that my question was about 3D files generated on the basis of imaging data; since some of the initial answers were specific for drawing.