View Full Version : Arm Rigging problems.

06 June 2003, 05:54 AM
okay, I've got a rigging problem I can't figureout. When I go to move the arm into a flex postion(similar to the pic) The elbow area part of the forearm twist horribly out of shape when the forearm is rotated. I have a seperate elbow and forearm bone in the arm. How do I fix this problem?
I'd like to figure it out so I can have a little animation in my demo reel.

06 June 2003, 06:02 AM
You might want to try weighting the skin. It looks rigid bound, so that's not good. Try smooth binding. If it's already smooth bound, then just use weighting. You should be able to get pretty good deformations with just bones and proper weighting.



06 June 2003, 06:21 AM
He's smooth bound. I think I just came upon a tutorial that has cleared it up for me. I think I just need to readjust the weights and attach the IK Handle at at different place.

Thanks! :)

06 June 2003, 01:20 AM
Hey Isamu7,

For an area like the elbow area, weighting alone isnt enough for really good deformation. You need to add an influence object as well and use set driven keys to drive the influence, so that it maintains volume. You see when Maya rotates skin around a joint, it basically does just that, it rotates the skin around the joint, but in real life you've got muscle and bones that maintain volume. So basically you need to recreate these bones and muscles with either influence objects or blendshapes. I prefer the influence method.
Just keep in mind, if your influences are setup correctly, you will hardly need to do any weighting at all.

I'm not sure what you are saying about the IK handles, but just two quick tips if you have an extra joint in your forarm, make the forarm joint, the last joint in the ikhandle and then snap your end effector to the wrist. I usually like to add more than just 1 extra bone and so I drive the whole arm skeleton with a simpler IK skeleton, but thats a whole other story:) Secondly, always have your joints setup so that they are slightly bent in a prefered angle. This way, the ik solver knows which way to bend it in. So for your knee, you'll always have your knee slightly bent forward.

I hope this helps you!!

Good Luck:thumbsup:


CGTalk Moderation
01 January 2006, 08:00 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.