What is the best way to approach/rig these types of wings?

[zjeffe20]

Hello!

I hope that is everyone is well!

I was playing with some methods and joint chains on the wings of a humanoid character. But I couldn't get the effect that I wanted.

I did the try to the blend colors method in the Hypershade, but the wing spread wasn't enough in my opinion. It also did lock me out of the "risk" of the wing, which made for some awkward joint structures.

I do know how to use SDK(set-driven key) and wondered if I could apply it to this model somehow. The part that stumps me is the lower half of the wing. Since it's all one mesh, I can't figure out how to look at it.

I wanted some feedback on my joint chain since I referenced the joint placement from the artist I got the model from. I think he uses Blender, so it wasn't ideal. But the other chains that I attempted just didn't work.

I was wondering If can have some suggestions or feedback to point me to right direction. I'm still new to rigging; maybe there is something I mistaking or just not seeing

I have a video, just of visualization of the model and my method

 

I was trying to achieve an effect where the feathers would follow the rotation of the wrist joint and still splay out when rotating up or down. From what I researched, I would have to do something with SDKs, which made sense for the separated mesh feathers. But with that block of mesh at the lower half, I couldn't figure out a way around it. This is why I copied the other artist's joint structure since it seemed to really work well for him. Those deformation was amazing, in my opinion.

Hopefully, that all makes sense.

If you need anymore videos or pictures for clarity, please let me know ! 

[Kahylan · Accepted solution]

Hi!

So there are two different questions in here that I can see. I'll start with the easiest one first.

How do you get the lower part of the geometry to spread out, since it is all 1 object?

The answer is simple, skinning and weight painting. This is the method of having a single mesh follow different joint based on their influence on the mesh. Here is a tutorial on that:

https://www.youtube.com/watch?v=lA5gVcLEZWk

Now to the harder question, how do you approach this wing rig?

And I have no simple answer for that one, because it depends on a lot of different things...

1) What is this rig gonna be used for? Is it used for Games, shortfilms, longer films or simple posing for stills? All of these uses have different needs and restrictions for a rig, both on the technical as on the user side. Knowing what the rig will be used for is key for knowing how to approach it.

2) How should the wing behave visually? Should the edge of the wing form a round curve when it gets lifted up with the feathers spreading evenly, or should it look like there is an elbow inside the wing? should the top few feathers behave like hands, spreading out more deliberately and not following the same spread as feathers in the lower part of the wing?

3) How should the wing control during animation? Should it basically have just the basics like open, fold and flapp, very easy to control but not a lot of liberty when animating? Or do you want maximum control, be able to pose every feather yourself. Which can be hard to animate but gives you full control over everthing? Or maybe a mix of both, having a standart wing rig for opening and closing the wings but additional controls for when you need to do more with it?

4) Does the wing need to do special tasks, like grab on to things, push against the floor or objects, where an IK setup is crucial for not going insane during animation?

I've been rigging for 10 years now, and these are the questions that I would ask my client before I even start thinking obout the way I will approach it. I've seen and built many different kinds of wing rigs, there is no correct solution for every project. And if I would list every approach, this comment would turn into a novel.

But if you answer those questions, I can definitely tell you which approach I think would be best for you.

[zjeffe20]

I firstly wanted to thank you for such a thoughtful reply; it means a lot. 

To answer your first question, This rig is made for the purpose of being put into unreal for game animations.

To discuss your second point. I wanted the a nice spread of the feathers, but since the wings would be part of attack animations. Maybe the hand setup would be better, I'm not too sure. 

For the third question I Think little of both is good. I want the standard open, flap, tuck and maybe one more control to help shape the group of the wings for better posing. But I believe wouldn't need to control every single  feather.

For the final question, I would love the process of seating up a Ik switch for the wing. I assumed it would be the same process setting the the arm. but how I might be rigging the wing, it might be a little different.

I have examples here of the functions what I want in the rig and what types of animations that would be done; hopefully these will help

Desired animations for the rig:

Desired wing spread effect

Desired IK effect and switch 

Desired wing shape control

Hopefully this helps and again i really appreciate your help

[Kahylan · Accepted solution]

Hi!

Sorry for the late reply, it was a crazy week.

So here is how I would approach this.

For the underlying structure of your  wing rig, I would use a normal IK/FK arm setup.

For the orientation around the main axis, make sure you install a Roll and Twist setup into your arm. Similar to the tutorial below:

https://www.youtube.com/watch?v=cEpUkO_3rXM

This should make it so the feathers at the shoulder move the least and then towards the wrist they gradually move more when the wrist and shoulder are twisted.

Now the side to side motion of your feathers is a bit more tricky. There are two different setups that I could see work here. One is quite easy to set up but can be a bit rigid, the other is more flowy/general but can be quite hard to set up.

The SDK approach:
Having your feathers spread out/fold in according to the lower arms rotation around the vertical axis using SKD. This will give you a nice spread if you set it up correctly, but probably will have some poses that won't work as nicely which should just be marked as to be avoided if there is a animation stlyeguide.

The bend ribbon approach:
you set up a ribbon going along your wing, which is set up to build a semi circle when the arm is bend 90 degress.
this can be done by having the offset groups of your ribbon control joints partially contraint to the upper and lower arm. The closer they are to the other part of the limb, the more partial influence they take from it.
On this ribbon you then set up sliding ribbon groups (using follicles, uv pin constraints or closest point on surface matrix constraints.) Each group containing another group or locator that is offset towards the back of the wing. Then you use the base joint of your feathers to aim at your offset locators or groups. This should give you a pretty good spreading in most situations, as well as the possibilty to animate the ribbon control joints to adjust the spread when it looks undesired.

For the "Hand feathers", I would use a auto/FK approach. Having a setup that automatically spreads using SDK, based on the distance from the wrist to the shoulder. with a second skeleton that is just an FK setup that can be used for custom animations. Both skeletons can be blended in to lead a result skeleton that puts out the final animation, similar like you would see in an IK/FK setup.

Also, I would set up a a joint chain for each feather containing 3-4 joints, with a curl attribute that affects the up/down rotations of the lower joints in the chain. This way you can easily animate the feathers to bend like they would be catching wind, which is important for heavy flying creatures.

Last but not least, since you are going into an engine. You need a single hierarchy bind skeleton. So once you have all your joints set up, duplicate the joints that would be bound to the skin, put the duplicates into a single hierarchy of just joints. Then parent and scale constraint each joint to the joint you duplicated it from and bind your skin to this single hierarchy skeleton. This will allow you to bake the animation to the single hierarchy skeleton once it is done to ensure optimal engine compatibility.

Once again, sorry for the late response. If I need to clarify something let me know.

I hope it helps!

[zjeffe20]

Thank you so much for your reply!

It helped a lot!