I’ve made a rig after a model of a ducks skeleton which I’ve applied. I had to give up on IK’s because the whole skeleton moved when I applied them. I tried to fix the Weight Paint issues as best as I could and simple poses work but then I get in trouble.
I’ve made a rig after a model of a ducks skeleton which I’ve applied. I had to give up on IK’s because the whole skeleton moved when I applied them.
Did you adjust the chain length?
I need to be able to make it fold its wings to its body, sit down and do a mock walk.
Just to fold the wings flush with the body? That should be a simple forward/back movement, or possibly some twist. I would consider shape keys. For sitting and standing, your mesh needs to must be constructed with the enough faces to allow for bending as you want. In the ‘step’ photo I see some deformations on the thigh and into the body that appear to be mesh problems, or the armature not aligning with the mesh.
I don’t like posting blend files in the forum but I’ll send it to whomever can and wants to help me!
To provide a general idea of what you’re working on, you don’t need to post files, just screen grabs showing the structure.
I am in a process of learning to rig as well. So I built a model with three very clear edge loops around all joints that need to bend / rotate. I was not sure about thigh being so close to the body; Automatic Weights some time fails. Build was just in case if I needed to manually weigh the mesh. It’s easy to select the edge loops you know.
It turns out that if your mesh flow is clear with clean edge loops Blender have no problem parenting the rig to mesh “With Automatic Weights”.
As for folding the wing, the arm bones itself have no problem folding. But the feather is a different matter. It need to rotate as it folds. Each feather shaft needs a bone or some type of control!
I don’t know what to say about the IK problems - I’d suggest you try removing the armature from the mesh, checking if the armature works as you want without the mesh, and then re-applying to the mesh. This would at least let you know if your armature is correct, or it might even solve the problem.
I didn’t explain my mesh answer too well, sorry - I was referring to the necessity of loops in the area of joints, just as you mentioned and demonstrated by ridix. It’s not the complexity of the mesh or number of vertices/faces, but where and how those faces are located. Loops around the joints allow for movement without too much influence of the surrounding mesh. Think of ‘bendy straws’ - there a lots of ‘loops’ on the bendy part, but the majority of the straw is a single piece. For an armature only three loops are necessary for each joint - one at the joint; one above; one below. Any more than three could add a slight bit more control and smoothness, but generally not worth the additional complexity.
On the example by ridix, see how the various loops are affected by the weight painting and that translates into more realistic deformation.
Wow, nice bird What kind is it?
I see what you’re saying and I’m gonna do my best to clean up the loop cuts to make it work better
I think I’m gonna add another joint in the wing to make it more clear how it bends. I won’t be using feather as it is a duckling and a fur-like texture will work for my purpose. I’m not going totally realistic but more illustrative.
When i did my other character for the same story as my duckling I had the same issue with some of the bones. It turned out that it was a parent issue with the mesh but I don’t have parent/ child relationships on this time. And he’s a robot with seperate parts so I took the easy way out!
Thanks! I know how my weekend’s gonna be used now.
That’s okay. I got a conclusion none theless.
Thanks both of you!
Okay - I’ve made some changes on the armature to make it more functional and applied loop cuts around the joints. Also I’ve slimmed his thigh down and created more of a bend in the thigh and wing. I haven’t applied the armature yet because I want to solve the IK issue I keep having first.
also, the advice on edge loops ridix gave were good, generally, but around the hips and shoulders, where there is no real clear joint, but the flesh should sort of curve gradually , edge loops actually hurt the aesthetic. It is better to have a very gradual weight painting
for fat articulations is better to use the mesh deform modifier and use the bones to control the mesh deform cage, revolt_randy has a really good tutorial about this https://vimeo.com/user3110296/videos
he had an IK control bone halfway up the shin, and the chain length of only 1. The controller was placed at the ankle, with shin pointing to it, and an IK length of 3 (shin, upper leg 1, upper leg 2), problem solved
First of all - as daren explains it I was looking at the order of IKs all wrong. He send me a blendfile with functioning IKs at the heel, which makes the shin move.
Secondly - this thread is not solved yet because I’m still working on finding out if the extra loop cuts helps me create functioning bending motion without mesh distortion. At the moment the IK daren made on my duckling seems fine so I still have the rest of the body and the wing motion to figure out.