orienting a ikRPsolver


adding a new ik Rotation Plane solver to an arm I face the problem of orientation.
the direction of the orientation (little white arrow) seems totaly unpredictable to me and when I set the pole vector afterwards my arm twists into a new direction that I dont want.

how do I install a ikPRsolver and keep my direction of joints through the process

… the orient joint tool doesnt seem to have an influence on the orientation of the RP, or?


my rigging bible, steven tubbrits rigging tutorial also just offers a workarround … isnt there a propper way to ad a ikRPsolver without rotatng out of the original position


ik on joints gets funky if you dont have the joints flat on 1 axis…bow legged creatures are a headache…

ie: when doing the leg…make sure the hip-knee-ankle joints all have the same X value so that the knee points straight to the Z axis. The ik will automaticaly calculate the Rotate Plane using the flat plane created by the 3 joints (imagine a triangle with the joints forming the 3 points…and that is your rotate plane -should be flat on one axis)

arms can be tricky so you will have to tweak the joints a bit to get the plane for the ik…so do a couple of tests and then freeze the joints after your done.


thnx for your answere - so it stays a bit a try and error thing

grüsse ans schöne wien - horche hier in brüssel gerade Ö1 webradio und wähne mich in der bildungsorientiert kommentierten klassikmusik der heimat nahe


I’ll just say what I usually do, I hope it helps.

Recently I found out that the joint orientation is bad. If you use FK, the joint orientation is just a pain in the ass. I do think it’s good for things like the fingers. The pink and thumb bend with an angle, so you could manually put in the joint orientation. I also found out that when I orient the joints and add an IK, the joints just pop away to a differant angle.

RPSolvers are great, they give you the abillity to orient the bones. Say you’ve got a leg. You’ll have an RP going from the hip to the ankle. If you’d use a SC you couldn’t orient the knee, with an RP you can. Just put in a locator and place it in front of the knee, select the loacator, select the RPSolver and do a pole vector constraint If you now move the locator, the knee follows, namely, the pole vectors get oriented using the locator.

Now you can leave the IKhandle alone and just use the locator. I usually use the IK’s in combination with a controler shape, to do things like a ToeRotateX or a FootRoll.

I hope this was usfull and helped you out, let me know the results :smiley:



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