Rigging oragnic spider legs
Hey Polycount, I'm rigging this thing at the moment, and I've straight away run into problems (I'm a pretty inexperienced rigger)
A: Should I build the leg like this? I'm just used to doing double knees, but is it best in this situation?
B: How should I do the IK setup? I just put the handle between the base of the leg, and the end of the claw/foot bit, and it works, but I don't really feel like I've got enough control. I found an old post of CGTalk where someone said;
But I don't fully understand what it is they're saying they did.
Am I best just sticking with my rudimentary IK handle across the whole leg, or is there some better way?
C: That bone that is sticking out the leg doesn't actually matter does it? I was under the impression that bones aren't actually skinned, they're just a visual representation of the direction the joint is pointing in space, right?
And here's the diagram I've been using most as anatomy reference:
Thanks !
A: Should I build the leg like this? I'm just used to doing double knees, but is it best in this situation?
B: How should I do the IK setup? I just put the handle between the base of the leg, and the end of the claw/foot bit, and it works, but I don't really feel like I've got enough control. I found an old post of CGTalk where someone said;
'I built a single chain ik at the top of the leg (coxa), much like a clavicle control, and then a regular ik chain leg under that with a reverse foot. The ball is at the end of the leg (ground contact) and the ankle is between the tibia and metatarsus. Worked fine, you do have two controllers to manage but the single chain is really just moving the coxa back and forth in a rather mechanical fashion so it is pretty easy to manage.'
Am I best just sticking with my rudimentary IK handle across the whole leg, or is there some better way?
C: That bone that is sticking out the leg doesn't actually matter does it? I was under the impression that bones aren't actually skinned, they're just a visual representation of the direction the joint is pointing in space, right?
And here's the diagram I've been using most as anatomy reference:
Thanks !
Replies
I don't think you need a double knee in this character. This is useful in humanoid characters to represent kneecap and it helps preserve volume. But to me this spider can easily go without while it gives you additional work.
Yeap Maya actually doesn't have bones but joints. I migrated from 3ds max and at the beginning it was quite weird but now joints seem more logical to me then bones. In the end all we need are the points of rotation (joints). And then we define which vertices we want to rotate around this point (skinning). So don't worry about that your "bone" is outside the mesh.
If you want to rig it with IK I would start it from trochanter down to the very end. Coxa would be rigged as a common clavicle. When you rig longer chain of bones with one IK then you don't have control over the angles of each bones.
Some people solve this problem by rigging the leg with additional reversed chain of bones. You can find this setup in "Art of rigging volume 2".
Maybe spline IK would work here too.
A couple of months ago I rigged similar character:
https://vimeo.com/76778462
I added custom control to change preferred angle of IK chain called Angle. It is shown at the end of this movie. I connected it with preferred angle of each joint in Connection Editor. This setup doesn't give you total freedom but I think it is good enough.
Good luck!
This is how I would set it up. I guess it's similar to what the quote you posted says. It's a Maya 2014 file.