K-3D (
http://k3d.sourceforge.net) supports .X, is free, and is quite powerful (there are some advanced matrix features and stuff I don't even UNDERSTAND
); unfortunately I can't stand the user interface (it seems to take about 40 clicks in various arcane places to get ANYTHING done!
). However, the developers are working on a new UI for Version 0.6 of the program, and I'm going to try out the CVS Version; if I can make a Windows build of it and it seems useful even in its development state I'll let you know...