keyframing
Andrew,
besides the upcoming tempo.kxp by the Yost Group (which will be the most
painless way) I have a couple of tips.
Use the fewest possible keyframes. View the path for the appropriate object and
examine the little yellow dots very closely. These represent the tweens and you
will need to make sure that there frequency smooth throughout the path. Use the
TCB and ease in/out controls to adjust for this. Another way is to create the
path in Acad with a point at a every keyframe. Import the path as a DXF and
make sure the number of keyframes for the animation matches the points on the
Acad polyline.