Painting and mirroring skin weights

00:04

We have the skeleton and the model is now skinned.

00:07

So let's take a look at updating the skin weights.

00:10

The first thing to do is quickly pause. The character

00:14

just use rotations for now.

00:16

We want to see how the current weights are looking.

00:20

It's usually best to work on the ways with the area paused.

00:24

So we can see here that the knee needs work.

00:29

Let's pause the arm to,

00:33

so we can now see how broken the model is looking with the default weights.

00:39

The way I tackle waiting is to first block in the main areas around each joint.

00:45

So let's start with the pelvis.

00:47

I will probably speed up the video in some sections from here onwards.

00:51

So don't worry if it looks like I'm working really quickly

00:55

set opacity and value to one. So we can assign exact full weights

01:01

to adjust the brush size. Simply hold down b and scrub with the left mouse button.

01:07

So we know that the crotch area needs to be fully weighted here.

01:10

So work your way around

01:12

up over the hip and around the back.

01:16

This is just rough, remember

01:19

and just stick with the left side for now,

01:22

right? Click on the next joint up and choose, select influence.

01:27

We can see that this has quite a big influence. So let's pull some of this back for now,

01:32

set value to zero. So we can remove the influence instead of add it.

01:38

And let's paint out this section.

01:40

We could use a harder brush here too.

01:44

All we want is the section which the joint is spanning weighted

01:48

paint out this down here.

01:59

OK. Next joint

02:02

and let's remove this area here.

02:11

OK. So we focus mainly on the left side. So let's update the right now.

02:17

All we need to do is select the model

02:21

and go to skin mirror, skin weights and open the options.

02:26

What this will do is mirror the waiting values across the model for us.

02:31

YZ is the axis we are going to mirror across

02:35

and this is the same setting we used when we mirrored the joints

02:39

and we need to mirror from the positive side to the negative. So left to right,

02:45

there are lots of other options to play with here.

02:48

Closest point on surface will match the weight to the

02:51

closest point on the opposite side of the model.

02:55

Rast uses a fancy ray

02:57

casting algorithm to decide the best points to sample from each side.

03:02

Closest component will match the closest vertices

03:07

with a symmetrical model like ours. The default options are fine

03:12

for more advanced mirroring options,

03:14

you can also choose how the components on

03:16

either side are associated with each other.

03:19

But for us again, the default settings will work.

03:23

And finally, we can choose to normalize the weight values when mirrored

03:26

to make sure they stay between zero and one,

03:30

we can leave this for. Now,

03:32

if I apply this, now

03:35

you see we get some errors with the model.

03:37

The vertices on the right side have jumped away

03:40

from the model because the weights haven't mirrored correctly.

03:44

This is because the left side is posed. So we need to reset it.

03:49

OK.

03:50

That's reset.

03:52

Now, let's try again.

03:55

So if we look at the weights, now

03:58

you can see they are symmetrical.