how to rig in maya joints and skinning splash

how to rig in maya: joints & skinning

Character skin weighting

The other half of the character setup equation is skin weighting. We have to tell Maya how to attach our character to the skeleton! When it comes to weighting, I like to work in a easy-to-hard progression. The video at the top shows how to use each of these tools, so I’ll skip past that and  just provide new info.

Bind skin with Geodesic Voxel

Geodesic Voxel make skin weighting almost work right out of the gate. This is much quicker and easier than the other Maya skin weighting options, especially when combined with:

Hammer Skin Weights

how to rig in maya hammer skin weights screen
the inside verts of the left leg are being pulled towards the right leg – hammer skin weights will make short work of problems like this

Geodesic voxel won’t get everything right, but some vert weighting issues are easy to fix – so easy, in fact, that Maya can do it automatically. This is stuff like the left leg verts being influenced by the right leg, or the side of the body being pulled up by the arm.

In cases like these, just select the verts and activate the hammer skin weights tool. It won’t fix everything, but it is an easy first pass!

Once the easy stuff is out of the way, it is time for the:

Paint Skin Weights tool

how to rig in maya paint skin weights screen
the heat map shows how heavily a vert is influenced by a bone – white to red is close to 100%, black to blue is close to 0%

Paint Skin Weights is an intuitive painting-based tool, that lets the user specify exactly how verts are weighted to the skeleton.

Every vert has more than one influence, and using the color ramp we can see how strongly each bone influences an individual vert.

One thing to note – all vert weights must add up to 100%. This is why there is no subtract mode for the paint skin weights tool: Maya wouldn’t know how to fill in the missing percentage!

The Paint Skin Weights tool should get us 90% there, and it works great for large areas of the body, like the torso, shoulder, hips, etc.

But certain parts of the body – like the knee and elbow joints, and especially the fingers, are handled more easily with the

Component Editor

how to rig in maya component editor
yeah, it is basically a spreadsheet but for vert weights. FUNNNN

The most precise method, but also the most tedious (IMO). The component editor allows the user to literally type in every vert weight manually. Best for tackling large groups of verts at once – to add or remove a bone influence all at once.

Up next

The delta mush modifier is a skin weighting tool that makes the process even easier – if you know what you’re doing!

Then I’ll talk about joint orients – a technical task that is necessary if you want to get a rig that functions properly.

And last would be how to link the skeleton you’ve created here to Maya’s Human IK Rig – a fully featured animation rig, without any of the headache of setting it up! Stay tuned!

 

14 thoughts on “how to rig in maya: joints & skinning”

  1. Hi james,, maya is tryn to make me nuts,,, 1st, my maya paints on d vtxs nt on d faces as urs on dis tutorial, 2nd d values on my vtxs r nt coming up in d component editor, its flat zeros after all i selected dem, n lastly, wen i try to rotate a joint, d mesh gradually try to separate from d joint,d more i rotate d less d binding impact, bt for sum areas, d skin bind is fine,,

    1. The Paint Weights tool only functions on verts, that is normal behavior. Not sure about the other errors though, try deleting history on the mesh and then rebinding it to your root node.

  2. Hi James,
    Terrific video! My models are all clothed and have some questions.
    What’s the best workflow for skinning clothes? Do you delete faces on the body mesh that don’t see the light of day?

    When asked in comments at YouTube about how to handle shirts, you say: “try skinning them separately and copy skin weights from the body on to the shirt.” If you copy skin weights, should you skin the shirt with all the joints in the skeleton, or just joints that influence the shirt?

    Are there any pros/cons to rigging controls before or after skinning?
    Thanks much!
    Ric

    1. Yes, delete the skin under the clothing. Unless you’re doing cloth simulation, you won’t need that geo.

      Skin the entire body first, then worry about creating the clothing. Once the body is done, you can copy weights onto anything that is derived from that mesh.

  3. Thank you, James. I finished going through the extended video the first time and love how you show how to use display layers to add influences to a skinned mesh.

    Do you have any thoughts about how a beginner should think about using Post or Interactive modes for normalizing weights when binding? You use the interactive mode. Do you ever lock influences while weighting?

    Again, great stuff! 🙂
    Ric

    1. Thanks, glad you enjoyed the video Ric! Skinning with interactive can sometimes be confusing to beginners, because what you see displayed on the mesh during paint weights won’t always match the behavior you see when moving the model. This most often happens when you think you’ve weighted verts either 0% or 100%, but still see unexpected influences. In that case switching to post might help, but in general I stick to interactive with the paint weights and component editor to knock out problems like that.

  4. hello james.. i am about to purchase the extended cut of the modelling tutorial..i just want to know if the mouth of the character is modelled in a way that allows movement and expressions (like mouth sync.) before i purchase… the youtube tutorial is excellent,please reply as soon as possible.thanks

  5. Hi James
    First of all, thanks for the great video, I learned a lot from it. I’d like to know if you plan on making videos about joint controllers, both body and face. I’m particularly curious about controllers for the face. Thanks!

    1. I just published my first face setup video, see the downloads page. Not going over controllerscontrollers yet, that will be somewhere down the road.

  6. Hey James, I’ve used your modeling video twice now and I think it’s fantastic. I’ve rigged both models and I have a couple questions.
    A) Why do some rigs have an abundance of helper joints?
    B) I’m trying to get proper deformations around the hips and shoulders. Do you have a tutorial for more advanced rigging/scripting?

    1. A) Helper joints are there because Maya joints can’t replicate the way muscles actually work. They are ok in areas that are basically hinge joints – like the elbow – but they can’t handle complicated areas like the shoulders. Helper joints can ameliorate some of the problems, but a muscle sim is the only way to get real deformation.

      B) nothing like that yet, sorry.

      1. Thanks for responding, I appreciate it. So is the muscle system pretty new? I’ve heard that it’s not worth using unless you have a very muscular person. The female I’m rigging has pretty average sized muscles. On older tutorials I’ve seen people use scripts/controls that slightly tweak the mesh/helper joints between the shoulder joint and elbow joint which are weighted to affect the shoulder and blend shapes to correct the animation. I’m aiming for her to be able to stretch while maintaining a somewhat realistic look. Would the muscle system be a better more efficient way of achieving this?

        1. Muscle systems have been around for years. The trade off is really setup time versus desired effect.

          If your character isn’t making any extreme motions, or is wearing clothing, then a few extra helper bones will do the trick. Bare skin doing extreme movements (think the Hulk) – that’s when you absolutely need a muscle system.

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