Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member
The other way to pose your armature is through the use of what's called Inverse Kinematics. In this video tutorial, I'll show you how to set up and use Inverse Kinematics. Inverse kinematics is the opposite of kinematics. Kinematics is when you pose your character by manually positioning the bones. In this case, though, we want Blender to point to and figure out for us how to pose the bones so that the bones reach some certain target. An IK is actually a constraint.
It constrains and forces the bone to behave in a certain way. The most common IKs are used in hands and feet, because instead of trying to pose how a leg moves, we can just establish an empty or any other kind of object and establish a relationship that says, hey! I want you to change this leg, however you need to, so that as I move this empty, I can move the leg and Blender figures out how to best move the leg so that the foot and leg bone and hip bone and all move to make that target.
So let's right-click on the hand bone, which puts us automatically in to Pose Mode and over here, let's add a constraint. Here under the Constraints, we have an IK Solver Constraint. In here we need to enter the name of the empty or the name of the object that the bone is going to point to. So what we're going to do is right about in here we're going to go ahead and press Shift+S and snap our cursor to the selection. That gets it right down there on the bone, put down there on the tip of the hand, where your palm of your hand would be, and press Space Add > Empty.
Now I'd like to name my empties based on what it is they are controlling. So if you press N to bring up the Transform Properties box, you can type in Hand.L. You can also go do it over here in the Links and Materials. When we right-select the bone, we can type in Hand.L and if you type name in right to match the case and all that, then you saw the bone shift a little bit. Now the bone and the entire armature all the way back to the root, will bend to meet and try to reach for this empty, no matter where it is.
So I'd like to carry it out at the front. Okay, normally we don't want the entire spine and everything deforming to meet this empty. Although, now you want a certain portion of it and the portion of the armature that you want to deform is called the Chain Length. Zero means the entire chain all the way back to the root. If we only restricted it to like say two bones in the chain, then only these two bones will move, as I move the empty around.
You can see that the rest of it stays the same. So for this chain, I'm going to go ahead and use the shoulder and you can see this yellow line that shows you where the chain ends, end part of the shoulder bone as well. Now when you add a constraint to a bone, it turns yellow when you add an IK constraint. A Green constraint is another kind of constraint, which is a Limit Rotation constraint. Notice I put on his lower forearm to show that this bone can only move as an elbow move, sort of as a hinge bone.
By limiting the Y and the Z rotations, now this bone can't like fly off to the side or anything like that and look unnatural. So now by animating the location of these empties, I can very easily make Captain Knowledge do whatever I want to do. So I'm controlling the whole rig just by moving these four empties. We need to go ahead and add another one down here to his foot. There's a couple of different kinds of foot rigs that people use.
One matches the IK to this foot bone. The other matches it to the toe bone. I like to go ahead and use the rotation and the location of the foot empty to control the orientation of the foot. That's IK rigging in Blender.
Get unlimited access to all courses for just $25/month.Become a member
100 Video lessons · 8540 Viewers
107 Video lessons · 37410 Viewers
94 Video lessons · 26732 Viewers
147 Video lessons · 6175 Viewers
Access exercise files from a button right under the course name.
Search within course videos and transcripts, and jump right to the results.
Remove icons showing you already watched videos if you want to start over.
Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.
Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.