Q: I have a simple branch texture map I made under Paint Shop Pro and applied it to a cone in 3D Studio MAX (to represent branches coming off a tree trunk). I then converted all the colours of the original branch map to white, except for the background which is solid black. When I use this as an opacity map with the same material for the cone I get my branches on a transparent cone (very simple technique for the more advanced artists out there). Oh, and the material is 2-sided and mapping is 2 x U axis (so that I have two branches per cone). Finally, I've moved the branches (cone) so that it sits in the middle of a cylinder.

Now, here's the question :)

If I leave 'Cast Shadows" on for the cone/brach object, strangely enough I get a cone shadow on the trunk (cylinder). However, the effect I'm looking for is to have the actual branches reflect their own shadows. CAN THIS BE DONE?!?

A: Sure, this works since Release 3.

You have to use Raytracing Shadows - they can "see" the opacity map! Click on the Spotlight, look for the Shadows settings and turn Ray Tracing Shadows ON (I think there are two radio buttons - Shadow Maps and Ray Tracing).
This kind of shadows can also "see" the filter color of your material and uses less memory. The drawback is that it is a bit slower, and cannot be used with volume lights.