switching IK/FK and back halfway an animation

I have some problems switching between FK/IK halfway an animation.
I have prolems with the arm jumping back to it’s initial state (rest mode) once I disable IK.
Suppose I want to do an IK move and then “lock it” and continu in FK, and maybe, just maybe switch back again later. How would I do that?

Or is this just a bad workflow? surely there must be a way though to “lock” an IK pose and work on top of that with FK?
Anyone? please? pretty please? (lol)

You can key the influence of the IK constraint. It is contained in an Ipo curve on the IK bone under “constraints”. Set the influence and click the “key” button to the right of the slider. This slides gently between wherever the pose would be with IK and wherever it would be with FK. You can pose both independently.

@ bugman_2000 : he knows about IPO curves for the constraints . He has a IK/FK switch that drives the constraint’s influence in the setup to his Lil Dude rig he posted not too long ago .

But FreakyDude, bugman_2000 is right of course . You have to key the constraint for the IK to hold it’s position . In your case you could just key the driver/switch object you have in your setup by keying it on the on position then when you want to switch to FK turn it to the off position and key that .

If you didn’t have a driver object or if for some reason keying that doesn’t work you’d have to key all the bones in the chain length for the IKed pose to hold after you had turned the IK constraint’s influence to zero . This is kind of like when people use auto IK and key only the bone they moved and can’t understand why the animation didn’t work (you have to key the LocRot of all the bones in the armature to key an auto IK pose) . But in your type of situation only the bones in the IK chain length would have to be keyed … that is if you didn’t have a driver for the constraint which should work if you just key that .

i remember wen i absolutly hated ik arms. wouldnt use em. but once u find out that it makes animating a guy picking up a box way easier and making natural poses easier ill never go back to ik,
i dunno, if i were u i would just learn to live with ik

well I love IK as well, but I got some tips from room335 to finetune, and it requires some FK, setting the pivot to 3dcursor and first setting the 3dcursor at the elbow didn’t work…

the problem isn’t that I didn’t key all the bones in the IK chain, the problem is that because they are in the IK chain, they have no locrotscale. So after i key the slider on/off with constant interpolation in IPO, the arm quickly jumps back to rest position before going to the position I intended. When I want it to go from the last IK pose, to the new FK pose.
Hope that makes sense, and I hope that’s what you ment. I haven’t tried it step by step now, because it is lunchtime and I am REALLY REALLY hungry, and because I tried it a lot yesterday. will try it again, after reading it again later today.
thanks for the suggestions either way…

i dunno, if i were u i would just learn to live with ik

It’s almost impossible to make natural swinging movements with IK. When arms aren’t anchored to something they should usually be animated with FK. IK arm movements tend to be really obvious, because your character’s arms move around like a puppet from Team America.

the arm quickly jumps back to rest position before going to the position I intended. When I want it to go from the last IK pose, to the new FK pose.

Is your FK pose fully the way you want it when the IK constraint influence gets keyed to zero? When the IK constraint influence is zero, the arm should go directly to the current FK pose.

So after i key the slider on/off with constant interpolation in IPO, t

Oh, and why constant interpolation? The transition is much smoother if it’s a bezier interpolation… unless I’m missing something?

because I figured I’d switch from full IK to no IK, the idea was that I do IK to a certain frame, and the next frame is fully FK starting from that previous frame’s IK pose.
I have an idea or two now, but I can’t test it till i get home… :frowning: