Which is the best/most efficient method of rigging in 3DS Max to use in Unity?

Ok, here’s the thing… I’ve had a few experience in 3DS Max and Unity. Not too advanced stuff, but enough to make myself a complete 3D mini-game. I needed character animation inside my game, so I looked for tutorials on rigging in 3DS Max, and learned some basic stuff about biped rigging. Seemed quite nice and easy enough for some basic use.

I’m thinking of taking things to the next level though, so I’m looking for the best method I should research and become experienced enough to get the most out of the models I’m working with. For example I would like to add facial rigging with facial expressions (lip syncing would be REALLY cool) or add clothes (maybe even swap clothing in-game), edit my model and partially re-use my previous rigging and more…

For the sake of argument, let’s assume we’re talking about humanoid characters, as I see it that would cover 90% or more of workload. As I’ve said, I’ve already use biped rigging, seemed REALLY convenient to use (or edit and use) .bip animations out-of-the-box. I believe I’ve encountered some other type of animation files, .bvh, but I’m not sure if they were meant to be used in biped rigs, CAT rigs or something else…

So to sum up, I’ve seen:

  • Biped rigging
  • CAT rigging
  • Generic bone rigging
  • Some other kind of rigging I’ve seen in tutorials with some circles and arrows and stuff, not completely sure what they are about to be honest.

Which on of them (or other) would be the most suitable for me to research and master to use inside Unity?

I have experience with normal bones, Biped and CAT (and pure helper-based aniamtion for simple stuff like chests that have a lid). I think that CAT is the most flexible and overall easiest way to go. The animation clip system allows you to create all the clips nicely organised and in one time line; When you want to export the model with animations, you just create a new clip that cimbines all the others above it as a collapsed stack, and voilá. The trick here is to have each clip’s global strength at zero save for the actual frames where something happens in it; This can be easily done by setting the strength to 0 in frame 0 with a new keyframe, then again to 0 at one frame before the animation clip starts, to 100% at the beginning of the clip, 100% at the end, and 0% again on the frame right after the end.

Biped is good enough for simple stuff but it is effectively dead, meaning support has been abandoned for many years as CAT is the successor. Normal bone rigs are ok too of course but IK etc. has to be made from hand for every new rig, whereas CAT has it included in the human rig presets.
But really, the thing that time and again brought me back to CAT is the ability to collapse all animation clips and have one long clip that can then be partinioned inside Unity. Having to work with a single clip the whole time for what will become tens of clips in Unity is very confusing and bound to mess up hours of hard work if keyframes are overridden. The most that can happen in CAT is that one single clip is broken, which can be easily repaired.