View Full Version : IK with Constraints problems

06 June 2011, 02:50 PM

I'm trying to set-up an IK with constraints and it's not working. The problem is that the End Affector gets dettached from the tip of the End Bone way before the whole system is straight. The chain system is as follows:

The red bones are supposed to rotate along their X axis only. The blue bones are supposed to rotate only along their Z axis. The black bone is not supposed to rotate at all.

I have attempted several approaches that result in the same problem described above:

1.- A default IK with constraints system from root to end bone, not working.
2.- A much simpler system consisting only of the red bones and the chain root null node, the latter "Looking at" the End Affector*, same problem.
3.- Intermediate approaches using the red bones and one or two of the other ones. I tried starting the system at the first red node. Same problem.

Thank you all.

* At this point, it is not possible to just set the End Affector as the Look At object of the Chain Root Null. It generates an infinite loop error. It is necessary to create a system a bit more complex (Null -> Blend -> Fetch -> Chain Root)

07 July 2011, 10:38 PM
So what is the problem right now? you're trying to keep the bones rotating only along the axis you want them to, and no other, and thats whats not working? problems keeping bones to rotate only along certain axes?

07 July 2011, 10:48 PM
Hello nemeru,

Thank you for your reply.

The problem is exactly as you resume it: I try to keep the bones rotating only along the axis I want them to, no other, and that's not working.

So after I set-up the IK system, the bones do rotate as I expect, but the whole system does not work exactly as it's supposed to. The problem is that the object that's meant to remain attached to the end bone until the whole system is straight, doesn't behave that way. It gets dettached a lot earlier when the bones are still flexed.

Thank you again for your help.

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07 July 2011, 10:48 PM
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