Ok I have an IK chain set up, but how do I get one bone to control the entire thing? For example in the ludwig rig for the hands to make the finger curl all you have to do is to rotate one bone that is just sitting right outside the finger tip. How do you go about setting that up?
Ludwig actaully uses an action constraint. When you rotate that one bone it causes certian bones to follow a keyed action. Here is a tutorial I wrote out a while back:
http://www.blenderprojects.com/calvin/actiondriver/
Another trick people seems to be fond of now-adays, is by creating a bone that stretches from the base bone (within the finger) to the IK bone. What you do is parent the IK bone to this bone. When you scale this bone it causes the the IK bone to end up as the base.
Here take a look at this video tutorial by bassam:
Yea I was looking at that video last night, although I leanred a lot about rigging it was hard to tell what he was really doing since the screen was so far away. He was talking about what he was doing, just didn’t really show how it was done. Each time I make the target bone a child of the one bone that stretches from base to tip than I lose the IK chain and the target wont move the bones that it was orignally a child to. If you could give me a little more information on that second techinque I would be o so grateful.
OK, here we have a chain of bones. Fing1A.R bone is parented to the hand.R bone. (So the chain of bones that deform the finger follow our hand)
Create an IK bone (do not parent to anything at this point.) Create an IK solver constraint for fing1C.R, our target bone being the IK bone we just created. Make sure to set the ChainLen to 3.
Now create another bone at starts off from the root of the last bone and ends at the root of the IK bone (you can use the shift+S feature to snap cursor to selected parts, and selected parts back to cursor.)
Make the IK bone the child of this new bone. And make this new bone the child of the hand.R bone.
Now when you scale this bone the IK bone will follow the tip of this new bone and end up at the root.
cheers thanks for the help.