In this video will be editing our skinning to make sure that our model deforms properly when we animate it. [MUSIC] So here we have our model and if we right-click on it, we can go to the Paint Skin Weights Tool. We can see here that as we click on things like spines and shoulders, it actually highlights areas that are white or black, representing areas that show paint distribution. What it kind of represents is for each joint, how much control does it actually have over that part of our mesh. White meaning that it has full influence, black meaning no influence, and gray being some balance between the two. The wrist here is a perfect example of an issue with our skin painting weights. Where if we try to rotate it too far down, it actually collapses the glove, exposing the cutoff arm. So, if we navigate in our Paint Skin Weights Tool to exactly what the left hand is doing, we can come down and use our Paint Skin Weights Tool with a value of 1, and an opacity of 1, and paint over it to control the deformation and to get it to stay and rotate with the joint we want it to rotate with. So in this case, we actually want this to rotate, not with the wrist, but with the forearm. We can see the forearm is fully painted to the wrist here. And if I paint this part of the glove to the wrist as well, it's going to mean that it will stay, these verts will stay with that particular joint. Often, rigging is a process of going back and forth and saying, are these verts moving exactly the way that I want it to when this particular joint is moved? So throughout this process, you'll see me rotate a joint. Here in this case, I'm actually animating the joint by setting a key frame of S at the intro and outro point in order to create a little reference that I can drag across inside of my skinning tool. This speeds up the process dramatically, so I don't have to stop, move a joint, check it in space. I can just create an animation that says, let's animate a deformation on here. And I can see it on any spot as I'm going. This is how I fix almost all of my joint problems. The brushes here is controlled exactly the same way that my sculpting or smooth brushes are, just holding B to change the size of the actual brush. While I'll never get any of these deformations exactly perfect, I want to get it close enough that the model reads pretty well. And just like with the skeleton, I'm focusing on just one side of the body at a time. I Shift+select over all of the key frames and delete them. Coming down to the bottom of my foot, I can see that my toe has a similar problem with bend. So I hit S to create a key frame at 1. I move it and hit S to create a key frame at 10 so that I can animate this exact problem. Popping into my skin weights tool, I'll be able to navigate through the skeleton to see the problem. This left toe base doesn't have nearly enough influence over the ends of the toe. So I have to paint some influence onto it. Now I could paint a way like a ray skin way by painting black in the areas, but that almost never goes well. Verts need to have some influence on it. And if we negatively paint influence, we don't really have any control over where it goes. So up here, if I paint away from it, it could go anywhere on the model. So I almost always paint white instead of black. So rather than trying to remove something from somewhere, I instead try to tell Maya where I do want that influence to go. Again, the stronger the white color, the more influence that particular joint has on it. So right now, I'm painting where the left foot should control it. Of course, this whole heel and the back of this foot should be able to control the whole thing. I can also turn on this color ramp. Which if the black and white is a little hard for me to spot, makes it a little clearer by showing red as pure influence and blue as areas that don't really have a lot of influence. But white and black still being areas of pure influence or not. It can often be easier to spot some of the differences that maybe would be hard to tell us slight gradations of the color gray. So possibly painting more influence at the top of my left foot will gradually remove this influence from my leg, which is one of the problems it's having. When Maya creates default skins, it doesn't know that I'm trying to make a foot or an arm or a finger, we have to tell it that. So often, these tools are here for us to make intelligent decisions about how we want this thing to deform when a joint is moved. If I wanted this to deform better, I'd probably need more verts and edges in this area. But for what this joint needs to do, I'm going to say this is okay. Let's focus a little bit on the ankle though and how I can see some areas rotating with the foot that I don't really want it to. I'm going to paint influence from that left leg rotation down onto this part of the ankle to say that this part of the leg should have a lot of control over this particular edge loop. What you want to think about is, in this case, the top edge loop should be controlled by the joint right above it. And the bottom edge loop should be controlled by the joint that's right at it. Now we can see up here that one of the reasons our leg is bending so strangely is because of how soft and gray this whole region is. By pinning a stronger influence across the upper part of the leg, I'll get less bending happening in that cuff when I move the knee. So let's animate a couple frames here. Rotate and hit S on my keyboard to create a key frame. And then do the same with my hip so I can see how it's going to deform out as well. Some of these areas get pretty complicated when they control multiple parts of the body. It's our best to think about how much of the body should move when just this one joint moves. So in this case, we can see the back of the leg isn't exactly collapsing the way we want. I always try to avoid the sort of noodle looking collapsing like around hollow noodle looks when it's closing. We want the outside edge to make a nice smooth transition, a nice round shape on the outside. And we want the inside to collapse in on itself pretty strongly. The same way that a piece of clothing folds up or collapses when it's being rotated. What we don't want is to feel like the leg is losing volume as it's closing up. So I'm taking what was a pretty broadly gray area, and I'm tightening it up. I can always smooth this out later if I want by holding Shift down on my keyboard while I’m brushing, which will actually smooth the verts out across the model. So this is a process of going back and forth, seeing how the shapes change when I deform, and deciding what areas need my attention next. There are more systematic ways where we would actually paint all of the weight straight onto the root first, and then work our way inside out to the whole model. Which is a much more precise way of working but it's very time consuming. For us, we're creating a simple model with fairly low pol geometry. And I just want to touch up a couple of areas that I think can look a little stronger. So on the hips, I want to get a little bit more control on the hips over things like the belt and the groin area. So that as I'm bending, those don't deform quite as much and they stay a lot more with the hips which is what I'm hoping for. Higher up however, I want the spine to have a little bit more control. Here I'm going to be painting in some pretty strong influences before I go back and smooth it out. And again, I'm only worrying about one side of the model because like most of the tools in Maya, I can always mirror these weights over later. Back into the hips, we're going to get some control over the groin area to make sure it stays, it maintains its shaped as the leg is pulling up. We don't want it to feel like the groin is collapsing as the leg is moving. I'm painting a little ring around here for the next level of the spine, which is closer up to where the chest is. We can always see in the view whatever is highlighted cyan is what is being controlled by the next level of joint chain. On something like the chest, I try to keep the joints pretty close to the center. And it's fair to say, anything around them, above and below, generally has a little bit of influence on it, especially when we're bending it to kind of like this. So now I'm deleting all of these key frames that I don't need anymore. It's always important before we start animating that we get rid of any temporary key frames like this that we might have made in order to help us weight paint. So I'm going to add a couple key frames into the bend of our waist because this is going to help control the way that our body is going to twist and bend. However, none of these are ever going to bend individually. Our spine doesn't bend joint by joint, it always bends as a system, so this is what I want to animate, a bend backwards. And then some kind of a twist. So I'm resetting some of my rotation here, and then creating a twist along the y-axis. And now I can control both its twisting as well as its bending. Because I want to be able to paint for both these cases. In things like the knees or the elbows, it only bends in one direction. However, something like this needs to bend in multiple directions. We see back here the belt's a real issue, so we paint more influence to the hips to keep that from collapsing in itself. Remember, everything we paint takes away from another area. All of this influence has to add up to a factor of 100% or 1 for Maya by the end of everything. So when we paint with a value of 1 on top of something, it's gradually filling in up until 1. Just like with modeling, I'm looking for silhouette. I'm looking for the kind of profile this strikes as it's stretching out. And it's just something I have to do in motion. So I did a good job of modeling the whole silhouette of it. Now I have to think about how its silhouette looks when it's deformed. So now I'm taking a look at the shoulder area. The shoulder is probably one of the most complex areas to get the weight painting just right on. You have a shoulder, you have the neck, you have the clavicle, you have spine joints. And all of them are influencing sometimes the same verts in the same areas. Especially this idea of when you lift up your shoulder, you actually create a little divot in your neck, and you have a little bump where your shoulder is. This can be done by doing the right kind of weight painting. We can simulate some of that. The clavicle is an interesting part of the body. When we raise our arm, our shoulders don't raise up any higher. That clavicle that's close to the chest actually takes over as soon as our arm gets sort of straightened to that T pose. This is what it's supposed to represent, and we'll be looking to weight paint that feature into it. You notice that I never translate or move my joints. They're always rotated, especially when we finished our rig, this is really important. These joints are not designed to be moved. They're only designed to be rotated just like on our body. If our spine suddenly translated its distance, moved its distance from another part of our skeleton, it would mean something is broken. Our bodies are designed to rotate, they just work better that way. So now I'm going to paint some influence with the shoulder rotated down into position, and make sure that the shape the shoulder makes here is good. We can see how we have some gray areas in between a white patch and then a gray patch and a black patch. We're going to really want to smooth a lot of this out. We probably shouldn't have any sort of paint influence dead zones anywhere inside of our model. Here, I'm painting more influence onto the left arm to control these parts of the arm, little areas in the armpit and the upper arm, being careful, at this stage too, to avoid accidentally painting influence anywhere I don't want it. I don't want to accidentally paint it when it's on the head, on the neck anywhere. Because then I might run into a case where I move the arm and parts of the hair move which just wouldn't make sense. We want to make sure that we're setting up how this thing should pitch or rotate when these individual joints are moved. In this case, our default rotation direction, because we messed so much with these actual joints, doesn't really fit in the angle that we want. So after we delete some of these key frames, in order to make sure that this rotates properly, we're going to have to switch its rotational angle to more like a world space. Or we can use the top view to use the perspective cyan colored rotate to rotate the elbow into position. Now we can control the actual bend. So we can see as we rotate upper parts of the armor being controlled, which we really don't want, so we're painting back over a one level influence on it. So that we see as much deformation happening in the upper part of the arm as the lower arm is rotating here. So in this case, I can actually select the verts that are controlled by a specific joint. Sometimes I want to check it, or I want to control those specific verts. In this case, I want to make sure that all of these verts move 100% with this joint. So I don't get any of that weird shifting. So I can select those verts, go down to form, and click Flood. This will flood all those verts with 100% influence and take away any influence from any other joint. This keeps us from having any of those tiny little movements sometimes are imperceptible across joints. In this case, this little bend in the elbow works really well for us, has a nice curvature on the outside. And on the inside, it presents a nice collapsing on itself, that little line we would get if our actual arm bent. So go through, make sure we delete all these extra key frames that we won't need. I'm taking a look at my fingers here. And it looks like some of the default skin weighting has actually done pretty decent job here. So for the most part, I'm leaving it but fixing it would be the same kind of process that we did with the other side of the body. But if we look at the head, we can see as we start to twist it, especially this head joint here, will change the shape of the head. We can see it sort of start to collapse. So I’m going to select all the verts that are involved in the head, including the ears. I’m turning off the textured view to make it a little easier to see everything. Then I Ctrl+Left mouse button and go to To Vertex, which is this, To Vertex selection. And now I can just flood all of this to the head. So that if I rotate this, it moves 100% with the head. The neck still rotates just fine and we no longer have a head shrinking problem when we try to turn our neck. It's always good to go through and just do a lot of checking. I move a lot of individual joints, and every time, I hit Z to return it back to its original position. I never try to move it back by hand, especially because on this joint chain, it's not all set to zero. In the next video, I'll show you how we can take this skin. In the next video, I can show you how we can take this complete skeleton and skinning system, and create a quick and easy control rig that we could use to make our animations. [MUSIC]
