Maya Ragdoll Page 2

Dynamic Rigging Tutorial (Aug 2003)

Come on! It wasn't that bad! Chin up, the light at the end of the tunnel is almost there!

Step 3: Test it!
Now basically we have the proxy objects all set. These will be driven by the dynamics. Right now, we'll test it with fields. Select the proxies and constraints and put them in another display layer. Turn the model display layer off by clicking the V button. Create a simple plane, scale it out and make it a passive rigid body by going to Soft/Rigid Bodies > Make Passive Rigid Body.

Select all the proxy objects and add a gravity field by going to Fields > Gravity. If you missed some, go to the Window > Relationship Editors > Dynamic Relationship and link 'em good! Now go ahead and let it rip! Click here for my playblast, which will most probably differ from yours.

Step 4: Restrictions
Ugh! What on earth was that? Well, the rag-doll behaved appropriately as a rag-doll would. It fell down and twisted into a bizarre pose. But if we want to use it on a human, we know that the human skeleton doesn't bend like that. So how do we restrict the "joints" so to speak? Here comes the crude technique that is characteristic of me! We use the geometry to restrict the joints!! Now modify the forearm by cutting and extruding some faces out to get the shape of an elbow.

If you play it now, you'll notice as the proxy object tried to move against a limit, the extrusions block it and keep it in within the limit. Repeat for the other parts. Now that you know better (heek heek) the next time you make the geometry, do this extrusion step then. For the knees, extrude a patella out of the thigh and lower the upper back set of vertices to give more freedom to the lower legs. Play it now and check the comparison.

The lower the vertices, the more freedom you give to that area. Modify the pelvis to give more freedom front than back. Also, extrude the sides to prevent the legs from flailing upwards!

A lot of tweaking and testing is in order till you get the desired effect. You may sometimes have to go back and re-orient the hinge constraints. Feel free to do as you like. Go ahead and assign masses to various part of the body (proxies) if you wish. This is what I came up with.
Click here for a playblast! Go ahead and make your own tweaks. If you find a real cool tweak, please tell me! :D

Riiight! What about my model?