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View Full Version : Newbie question - IK goal won't work.



Mark Borok
12-11-2004, 08:05 PM
This is making me tear my hair out right now. I create a leg object made up of a hierarchy of simple boxes. I add a null , position it between at the pivot point of the foot, set it as the goal object for the foot with "Full-time IK" and "Match Goal Orientation" turned on. Now if I rotate the null the foot rotates with it, but if I move the null the foot doesn't move.

I have "Inside Lightwave 8" and I watched the video tutorial for rigging a skeleton. I seem to be doing everything right. When I open the skeleton scene and fiddle around with it I can add nulls that work just fine as IK goals. However, in my own scene file I can't. All I see is a dotted line connecting the null to the foot, which stretches when I move the null away.

Can anyone tell me what I'm doing wrong? The manual doesn't seem to help either.

Digital Junkie
12-11-2004, 09:07 PM
If the IK is set up properly you should have a solid light blue line from the bone with the goal object to the bone that is set to not be affected by IK of decendents. Could you post a screen shot out of Layout?

Dodgy
12-12-2004, 09:14 AM
Go through your bone chain and check:

That you only have 'Unaffected by IK of descendants' only on for the TOP(root) of the chain, not for every bone along it.
That you have IK chosen in some of the Heading/pitch/bank Controllers (under MotionOptions>Controllers and limits) for at least some of the chain bones which are not the goal bone or the root.

Mark Borok
12-12-2004, 09:57 AM
That you have IK chosen in some of the Heading/pitch/bank Controllers (under MotionOptions>Controllers and limits) for at least some of the chain bones which are not the goal bone or the root.

Thanks, that was it. Funny thing is, I remember at one point going in to check that exact setting, but it must have been for the wrong bone, or else I was doing something else wrong at the time.