If you want to use directx you will need to export to .3ds to convert to an .X file. You might look on the opengl.org forum. I saw something like what you're asking about there a few months ago in one of their many tutorials. opengl is another good way to go and you might want to chech into that. As to whether you can save 3ds as a motion file the way you can with an obj I'm not sure but I think that they are static. You may have to make a series of 3ds files the way we used to do for 2d (like a flip book only in 3d.)