View Full Version : character's cape twists 'cause of bone

01-11-2009, 10:18 PM
Is there anyway to stop my character's cape from twisting when he pivots his lower arm on the bank axis?

He's got a standard bone setup and he's wearing a robe in addition to a cape. I want his arm and robe (but not the cape) to twist as the bone turns on the bank axis. And I want the arm, robe, and cape to move when the bone pivots on the pitch axis.

I've tried disabling the bone for the cape layer and applying clothFX & collision but it's too darn complex for the computer to calculate and for me to animate efficiently. Surely there is some way to disable twisting from the bone for a specific layer?

01-12-2009, 12:25 AM
The term 'standard bone setup' can mean a lot of things to different people. In this situation its more to do with how your bone influence is setup and controlled.
If the cape is part of the same object as the rest of your character you may need to use weight maps to determine which bones have more influence on particular geometry.
Another option is to make the cape a separate object in another layer and give it its own set of bones. If you plan to use dynamics putting the cape in its own layer makes more sense. You can also use a lower rez version of the cape as a proxy object to speed up the dynamics calculations then metalink the higher rez version of the cape to the proxy.

01-12-2009, 12:29 AM
If you want pitching to deform all areas, but banking only deform some areas, then just create a bone for the cape which counteracts only the banking.

Add a child bone, make it the same length and set it's Z position to 0 so it occupies the same space as the previous bone. Assign this bone a 100% weightmap including the cape only. Use follower or an expression so that everytime the parent bone rotates on bank, this bone rotates in the opposite direction.

If you have the cape on a second layer, perhaps give it it's own bone setup entirely and drive these using the bones in the main layer via motion modifiers or expressions. Probably alot of work though.

01-12-2009, 08:17 AM
Both excellent suggestions. Thanks very much.