View Full Version : Planting Elbows and Knees

05 May 2006, 04:47 PM
Just a quick question guys, i have looked through the forums and on the net and i cant find any info on this.

Taking a standard IK arm or leg how could you add the function to be able to plant the elbows or knees.

Its something i havent needed all that often but when i have its a pain to have to animate because you have to work with the hand, shoulder and elbow controls, and pretty much key every frame to keep it stable.

The only idea i came up with was to have two IK chains, the normal one and the new elbow one. And then have a switch. Leaving the forearm in FK. Is this possible?

05 May 2006, 09:17 PM
hey Alex,

yeah this thing is possible. If your only talking about an IK arm having an elbow plant option, then you would 3 arm joint setup. One for the normal IK arm, one for the elbow plant option (where you use about 2 IK chain, one from the shoulder to elbow and another from elbow to wrist joint), and then you need a resulting joint setup. You then Orient Constrain each bones of each setup to the corresponding resulting joint. Then you can create a custom attribute to ur hand control or whatever and use expression or connection to blend the Constraint waight value.

Hope that make sence. Btw m blabering all these without knowing what software ur using, but this should work for maya.

Happy Rigging :thumbsup:

05 May 2006, 08:20 AM
hey there, i see what your saying. And it ties in with what i was thinking.
Time to do some tests i think. Once i have anything i will post the results :)


EDIT: Im using max, but its all the same :P

05 May 2006, 06:22 PM
I have done the same for a gambling video game where the characters were back and forth from the hands to the elbows on the table. A reel pain but it worked well once the animators were used to it. And yes, it doesn't matter what package you are in to do it. I had four arms, IK Wrist, IK Elbow, FK and the follow joints that were skinned to and exported to the game engine.

05 May 2006, 12:52 PM
thanks PEN, with any luck i will be starting on this in the coming month i will post the results once i have them.

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05 May 2006, 12:52 PM
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