View Full Version : Constraining IK Problems

06 June 2003, 10:16 AM

guys, how do you constrain an IK to move with the joint that is currently attached to it. like an arm rig using IK.

like the one on the gnomon DVDs? Alex said he used mel scripts but yeah, didnt explain where or how to get and do it.

and how do you snap the IK to the joint so when you over drag it, it snaps back to the end effector's location.


06 June 2003, 12:44 PM
Are you using Maya 5?

I believe there is several enhancement on Maya 5.0 to handle IK/FK rig.

In older version you can temporarily disable solver for IK handle, to let you pose your character as FK, and with snap enable your IK handle will move with the joint, so you can key it. And when you activate back the solver it then will move as you key it.

You can use MEL script, and assign it to hotkey so you could toggle the state without using channel box or Attribute editor.

But in Maya 5, it maybe treated differently. AFAIK Maya 5 will have IK/FK in one system with blending value, so you could animate with IK and at somepoint pass it back to FK by animating the blend value and so forth.

This reduce the necessity to have two system when you rig the character, Maya will create both system for you.

Just my understanding, when we talk about IK system, the position of the IK handle is controlling all joints rotation, so you cannot rotate the joint in the system. And FK system, joint rotation will give you the position of the end joint.

Maybe it's a bit confusing when you jump to Maya 5.0, which will give you both system at the same time.

Maya system now should work similar with Motion Builder control Rig.

Best regards,

06 June 2003, 07:54 PM

Go check this thread out:

There is a tutorial to do something like that. I obviously wont really apply to Maya 5, but you might still find it useful.


06 June 2003, 06:35 AM
ill look into it.

i have jason's mel scripts, dvd re: rigs

and even his source files but i havent had the time to really dig them.

06 June 2003, 09:13 AM
If you've got all of Jason's stuff, then you pretty set. The fast animation rigs DVD has got a nice section on IK/FK blending with some cool scripts and stuff, but you should still check out that link.

The link's tutorial also show's you how to setup up extra bicep and forarm joints to get better twisting deformation :thumbsup:


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