Let's tackle our first actual binding of geometry to the joints, what is known as skinning in this
lesson, and we're going to do that on the spine.
But first, let's let's start from where we left off and we have the legs done and we need to get the
hips done.
So the hips are going to be pretty easy because we have our own hip joint here, which is controlled
by its own controller.
You can see that we can start to play with our rig a little bit there.
And all we need to do is simply just parent that to the hip joints so we can select the child first.
And then the parent had PE and now we have the hips will move along with the legs and it's can be very
distracting once you get to this point to just start playing with the rig like this, everyone does
it.
So if you get distracted for like 15 minutes and you just do that, that is very normal.
All right.
So let's talk about actually binding the geometry to the joints here, because we have a lot of spine
joints.
And how do we approach this?
All right.
The easiest way for us to do this is going to be to combine the mesh of the spine joints so that individual
pieces anymore.
Now that we have this kind of done and we like where they're at, we can do that.
So let's find them most select one and head off in outliners.
We can find all the spine joints here.
It's going to shift select all of them and go to the modeling menu up here, go to Mesh Combine.
And now they're all one piece.
And we have all this nasty history here of all these groups.
So we can, with the spine still selected, go to delete by type, go to history.
And now we get rid of all those nasty groups knowing his spine and let's begin selecting the joints
that we want to include on this binding.
So you want the hips because we have this little bone down here, the tailbone basically that is below
this joint in here, this kog joint.
And I'm going to open up the channel box here so you can see the names of things and we can see it's
constrained constraint, the controller, what we would expect and all that stuff.
But just you can see the names here so we could start here.
But we're going to leave out this hip control that we just added to the hips.
And we want, I think, this tailbone to follow this hip rotation here.
So we need to include this joint to start with the hips.
All right.
And then we can hit CU.
So we get this select tool and shift, click and drag and select each joint up the chain.
And as the bottom one turns white, you know, you selected the next one.
Right.
So everything up to this one has been selected.
It can be a little confusing on what you have selected, so just make sure to pay attention to that.
So we basically want to select all the joints that are included in the spine.
We don't want to select the head joint because we'll do that later.
And that's going to be just for the head.
So we'll leave that one.
And now the last thing we select is this geometry.
So let's go to the rigging menu here and go to scan and look at the Byrn skinned options.
Let's walk through this.
There's a lot here, but it's really not that complicated.
The only thing you really need to look at is what we're going to bind to.
We don't want to bind to the hierarchy.
We want to make sure we bind only to the selected joints, because in the hierarchy there's the shoulders,
the clavicles, the arms.
There are a lot of things in the hierarchy, but we just want to make sure we're we're binding to the
selected joints.
That's why we made that selection.
And then all this default stuff is pretty, pretty good out of the box.
There's no real reason to get into this stuff.
It's a lot of crazy math and it's not worth getting into from a beginner level.
I rarely change that stuff, normalize the weights, blah, blah, blah.
That's fine.
Weight distribution is fine.
And the next big thing, really, the second big thing you wanna look at is max influences.
And that means how many joints do we want to be able to influence a vertices?
All right.
Did we want, let's say, the neck joint appear to possibly influence this bottom vertices?
Absolutely not.
That makes no sense.
We don't want five joints build influence.
One vertices that might make sense on like I don't even really know what like a finger or something.
I don't even know when that would make sense.
But so we want to reduce this.
We really we just want like to right.
If you look at the distribution of joints, you know, the distance between them dictates.
How many influences you're going to want?
I would think so.
You could do like two or maybe even three would make sense, but I'm not going to stick to two for now.
And that's really all you want.
And the resolution is basically the size of the weight maps, I believe.
And we could just crank that up a little bit to five, 12.
That's pixels.
And yeah, then we're ready to go.
Let's just apply.
So it's going to think for a second and then it's going to deselect everything so we can close this
now, select all of our spine controls here and take this for a spin.
And it looks like it's working pretty darn good.
So we actually have defamations happening on the geometry.
This is a totally new thing, right?
We haven't done this before.
We haven't done binding of geometry to joints.
So now we get to see how the geometry deforms along with the joints deformation.
Right.
We get these kind of hitches here and that's OK, because it's kind of that the extreme levels here.
And also this is something to think about, you know, the density of joints.
This is kind of the trade off, right?
Like for a better kind of faithful interpretation and defamation here, we would need a lot more joints.
But the trade off is how many controls do you want to use when you're animating?
Do you want to keep track and animate, you know, 10 controls in the spine?
Probably not.
That's maybe overkill.
And when you're animating, you're going to want to, like, not enjoy that.
So, you know, this is another example of what to think about when you're rigging.
How many joints do we really need?
How many controls do I want to give the animator?
Will they hate me if I give them a ton of controls and it's useless because they're all they're going
to use them all together.
And is there another way to get around this type of wonky defamation?
And and actually there is and that's something we're going to cover in the next lesson.
So now that we've found the geometry, let's take a look at what that is actually doing behind the scenes
and how we can affect that.
You know, we can see that there's these sharp edges here when we deform this in a drastic way.
But you know what's really dictating the influence over the geometry, right?
Like if we look at the tailbone, it's not it's not totally moving one to one with the joint.
Right.
Like, if this was moving one to one, this should be pointing over here.
Right.
It should be pointing the same axes as the as the red X rotation here.
Right.
But it's kind of lagging behind.
Well, let's try to figure out why that is.
So there's something called weights, right?
And that dictates how a Vertices is going to follow a joint.
And remember, we did the maximum influences at 2:00.
So we know that only two joints can act on a vertices.
So let's open up this thing that we can actually see what I'm talking about.
Let's go to skin and with the spine selected, let's go to paint skin whites.
And this is another big piece of the puzzle here when we're talking about binding joints.
So when I click that, you can see now we have this kind of black white representation.
We can actually change that down here to use a color ramp if we want.
And what this is saying is and this is also shows why it's important to name your joints, because now
we can see which joint we're actually selecting here.
Right.
This is very important.
So I'm going to go back to black and white for a second and.
And I'm going to change the size of the brush, the brush is pretty big, so I'm going to go down here
to stroke and go, yeah, point to yeah, looks pretty good.
And what we can do, there's a lot going on here.
Right.
But and as is typical with Maya, it's not as complicated as it looks.
We have the Moedas paint, the paint operations replace and the value we're going to paint is one.
So we're going to say 100 percent follow bones.
Hips.
Right.
This is the joint we have selected.
This is the joint we are affecting the geometry on.
Right.
So if we start painting here, you can see it turns a brighter white.
That means 100 hundred percent.
Right.
I mean, this thing is going to follow 100 percent this joint that we have selected.
So I'm going to paint this entire little lower tailbone joint because I know I want it to follow the
hip joint.
One hundred percent.
It's a whole solid piece.
Right.
So let's just paint this whole thing just clicking around and painting it.
We can also get a more accurate, more faithful look at what the paint values are by going into the
color.
And we can see now that, you know, white is going to be hundred percent and some of this is still
red.
So we could really go over this a bunch of times and make sure it's it's actually one hundred where
the other black and white map wasn't really giving us that.
I was just giving us a kind of a larger interpretation of these values.
OK, so that's that's good enough, I think, for our purposes.
So let me go back into our manipulating.
I just hit to get the tool up here, the move tool and easy to get to rotation.
Now check this out.
Now it moves one hundred percent.
Right.
It's following exactly where that hip joint is moving.
And that might not be what we want, because now you can see this intersection, it's pretty rough,
right?
It's starting to crash in and to form a little bit, so we might not want it to be 100 percent, but
but you get the idea now and why this is important and how we can affect the weights all along the spine.
Let's not back in here for one second.
I'm going to use the last use tool option over here to get back.
And from the bones hips, the other thing that you can do, which is pretty nice, is go to smooth and
then just flood and watch.
Watch this over here.
I'm going to flood.
And this is not a good example, I think typically what will happen is it will smooth out these hard
edges.
So let me let me let me find a better example here.
Let's go to the Kog here and let's see if that'll just happen by default on the default values.
Yeah, everything looks like it's pretty smooth, quite a bit.
But if we had harsh values here, um, so we have the paint tool.
Let's go to a place and I'm just going to do that.
All right.
So now we have one hundred.
It's pretty harsh.
It's not a smooth edge.
Let's go to smooth and then flood.
Now you can see what the flood tool does.
It just softens those edges out.
So I can be very, very useful when you're painting.
And it's hard to get kind of precisely what you're looking for.
And you can also, of course, paint that on.
But yeah, all this stuff looks like it's already really smooth anyways.
So it's going to be harder to see that kind of a change here.
But that is the paint skin Waite's tool.
And in the next lesson, we're going to take a break from this rig and look at another rig and how the
paint can weights work on more traditional human rig and how to do pose space defamations.
Thanks for watching.