Ok I was thinking about how I want to setup an armature for a finger.
I came up with this:
In this forinstance Bone,Bone.001 & Bone.004 are the bones that deform the mesh.
Bone.002 is the IK for Bone.004 and is the 1 bone that I move around. Bone.004 also has a copy rotation constraint targeting Bone.003, and the same goes for Bone.001.
basicly this seems to do exactly what I want… I have one bone to move around and as long as I do this well… everything else seems to follow correctly.
In the file… Both Bone.001 & Bone.002 have a copy rotation set to the bone called ROT. The IK bone is the IK for Bone.002 and is the only bone you move. Because ROT is rotated when you rotate IK to bend the fingertip, Bone.001 also has the tendency to bend in the correct direction, which is what I was looking for.
I’m implementing the same system for arms now, and the same copy rotation trick for legs/feet, but in a different way. Basicly I end up with an “IK” bone for each ligament which I move/rotate and everything seems to work nicely. Of course the old “standing tiptoe” trick doesn’t work for it, But that takes rather a large system.
I used to use IK fingers, but stopped when I realised its a bit of an overkill in blender. Without proper rotational constraints it can become quite tricky to pose correctly.
Not to mention the fact that with so many ik / solver bones, the whole armature can slow down quite dramatically when posing.
With fingers and arms I use FK. And IK for legs, spine and head.
