Reading bone rotation values due to IK

[jim c]

I have a small bone chain (for an arm, so basically a forearm and bicep bone). I have a blendpose that is set up to react to changes in the in bicep bones rx value. This works perfectly when you rotate that bone with FK. However if the bone is rotated with IK then it doesn't seem to work. So after experimenting some, I think I understand what's happening. Once the IK is active, the rot values are actually in the IK Chops node, not stored in the parms for the relevant bone nodes. Which makes perfect sense. So that means that instead of a single fetch for the bicep bone you actually need to make a little network that does:

1) fetchs the bicep rx val

2) another fetch to get the biceps rx value from the IK solver it's hooked up to

3) use a composite chop to blend between the two values based on the current frame, and the bicep's IK solver blend value

 

Does this make sense, or is there some other way to approach this?

[anim]

just get rotations from inversekin CHOP node, so directly the channels from CHOPs

they represent rotations for the bones and are properly blended with Blend Parameter on inversekin CHOP so you always get correct rotations whether IK is on or off or in the middle