CGTalk - simple rig, leg problem

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ElysiumGX

03-23-2006, 12:23 AM

I've tried searching for answers to this, but not sure what to look for, or what it's called. I'm familiar with XSI, but new to rigging.

I have a character's leg rigged with two bones...a simple 2D chain. It's a low poly mechanical type leg...no foot.

When I translate the control object that moves the effector forward, and straighten the leg, it inverts it's direction. Like it twists 180 degrees. It only does this when straighten to it's maximum.

How can I set this to keep it's orientation?
Some legs I don't have this problem.

Also, sometimes when I locally rotate some control objects in one direction, they actually rotate in the other.

Am I breaking some obvious rule of rigging that I've overlooked in my tutorials?

mattmos

03-23-2006, 03:25 PM

For the leg you need an upvector to keep it orientated in the same direction. Do a quick search in the manual/help section.

For the inverted rotation are you mirroring/scaling in -1 the control objects? After you do that it may be worthwhile freezing the rotation of the object prior to setting up the rig.

hope this helps
matt

ElysiumGX

03-23-2006, 04:03 PM

Thanks for the reply. I probably should use up vectors. I did for the arms. But the legs are unlike human legs. There are 4 legs.

After some trial and error last night, I think the biggest problem was I didn't Duplicate Symmetry. The 4 mechanical legs face outward from the body, like an octopus. I created the front left leg, then Duplicated Symmetrically to the right. Then Duplicated Symmetrically both front legs to the back. That appears to have solved it.

This was my test to learn rigging instead of using the Biped Guides.

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