All language subtitles for 07_10_skinning_basics

- [Zach] In this video, let's have a look

at the basics of skinning.

Skinning means to make a mesh deform

along with the bones
of an armature object.

Here I have a very simple example.

Here I have a mesh with
two cuts in between,

so basically a cut exactly

where the joints of the bones are,

and we have an armature object
with three connected bones.

So before we connect
the mesh with the bones,

we need to understand that each vertex

of our mesh object has a certain weight.

So that means if I go
to Edit Mode later on,

we tell all of these vertices to move

along with a specific bone.

However, in some areas,
like here, for example,

we are on an area which
this vertex here could move

along with this bone
and with this bone here.

And in this case, we can give
this Vertex a certain weight.

That means it should
move along with this bone

to a certain degree,

but it should also move along
with this bone down here

to a certain degree.

And this we define through vertex groups.

So we can group certain vertices

to move along with a specific bone.

For that, we have the Weight Paint mode,

which I will discuss in a second.

First of all, let's go
to the object data tab

and Vertex Groups,

and let's select these vertices up here.

Add a new group, and
then before I assign it,

we can see that we can define
a weight from zero up to one.

Zero means of course nothing,

and one means it should
later on move fully

with a specific bone.

However, if I set this to 0.5

and then later on assign this vertex group

to this bone here,

then it will only move
50% along with the bone.

So if I now would hit Assign,

then we group these four vertices
here with a weight of 0.5.

So now you just need to understand

each vertex can have a
different weight in general

from zero to one,

and we could even create
a new vertex group

and say that this specific vertex here

should also have a weight of 0.5.

That means it has the 0.5 in this group

and 0.5 in this group.

So the weight is basically spread

across these two groups here.

So luckily we don't have
to manually do all that

because Blender is doing this for us.

But before we do that,

let's have a look into
the Weight Paint mode.

If I go over to Weight Paint
mode, everything turns blue.

And here instead of
working with the values

from zero to one, we can
work by painting on our mesh.

Let's enable this button here
so we can see all the vertices

and press A to select them all.

Now we have these white points here,

and now we have a brush to
draw on our object here.

And up here we can see the
weight is currently set to one,

but we can also change
this to any other value

between zero and one.

And now when this is set to one

and I paint over the vertex here,

I apply the weight to this vertex.

So and you can see this specific
heat map will be generated.

Dark blue means zero, and
then it's turning slightly

into light blue, green,
yellow, orange, and red.

Red is basically a value of one,

and dark blue is a value of zero,

and all the colors here in
between are different values

between zero and one.

So and you can see, although
we are just painting a vertex,

it will automatically create a gradient

to the direction of the next
vertex and across the phases.

So although this is all colorful now,

we are actually just
painting the vertex here.

And now I could paint the other one,

this one here on the other
side, and this one here as well.

So and all I did basically now
was creating a vertex group.

And inside the vertex group,

I defined the weight of
the specific vertices.

So that means if I go over to Edit Mode,

you can see that this
vertex group was created.

And down here, you can fully
ignore this weight value here,

because this is just something you define.

And then when you assign something,

this weight value will
be taken into account.

However, now in Weight Paint mode,

this new vertex group was created.

And if I hit Select,

you can see that these
four vertices are included,

which I painted in Weight Paint mode.

However, in Edit Mode,
we can't see the weight.

This we can only see in Weight Paint mode.

So let's go back to object
mode, remove the vertex group,

and now let's select the mesh first,

and then with shift the armature.

Press Control + P to open
up the Set parent menu,

and here we have some
Armature Deform options.

And here let's go with Automatic Weights.

If I click on this, it will
basically detect the vertices

which are closest to a certain bone

and then create the vertex
groups automatically

for each bone.

If I select the mesh now,

you can see one vertex group
was created for each bone.

If I go to Edit Mode and select these,

you can see that now certain
vertices are included.

And as mentioned, in Edit Mode,

it will always select a
vertex within a group,

no matter how strong the weight should be.

That's why sometimes we have
just everything in here.

And if I now switch over
to Weight Paint mode,

we can actually see the
weight of each group here.

If I select these, you can
see how each group is painted

and how the weight of each
vertex is for each bone here.

For the top bone,

you can see the top
part is mainly included,

but the closer it gets to the second bone,

the greener it gets.

That means here the weight is pretty weak.

If I go to the center bone,

you can see it also has
included these two vertices here

or the four vertices here,

but also not with the full weight.

Same applies to the bottom bone down here.

And now we could go in here and say,

for example, the top bone,

I want that these four
vertices here will fully move

along with this bone here.

Then I could just paint them fully red

with the weight set to one.

Same for the bottom one.

I could say, "Okay, these bones down here,

let's press A to select everything here."

These vertices here
should be fully included.

That means I paint the weight to one.

And there's a little trick, by the way.

You can also enable Auto Normalize here.

That means if one vertex, for example,

this one here is in two vertex groups,

and I go to the center one, paint in here,

then it will automatically
take the weight away

from the other vertex group up here.

So but we don't wanna
make it too complicated.

Let's switch over to Object
Mode, select the bones,

go into Pose Mode.

And now you can see when I move this,

it will adjust the mesh
according to the bones here.

Let's leave the bones in this position.

Go back to Object Mode.

Select the cube here, and go
back to Weight Paint mode.

And now you can see the exact deformation.

And now we could go in here
and change something even more.

So for example, the center bone

should not include something down here,

so we can set the weight to zero.

Make sure that we erase
everything down here completely.

You can see how this is shifting around.

And it should also not include
anything from the top here.

So I can erase this part here as well.

And since Auto Normalize is
enabled here under Options,

it will automatically apply
everything I take away

from this vertex group to the
other one on the top here.

And now back back in Object Mode<

and here back in Pose Mode.

If I now move this,

you can see that the top part
is now perfectly moving along.

So this is how skinning works in general.

And by the way, one side effect
which is happening here is

that the mesh object will be parented

to the armature object.

That means in Object Mode

when you are moving the armature around,

the mesh will then automatically follow.

And one other thing to keep in mind

when we connect a mesh
to an armature system,

there will be a armature
modifier added to the mesh object

where the armature object is connected.

So everything runs through
a modifier basically.

So what I just showed you
works for organic objects.

That means big meshes which
are connected to each other.

However, as you maybe
remember in Cubic Worlds,

we are working with cubes.

So here I have three cubes.

Let's join them with
Control + J to one cube,

which is a bit easier.

However, in Edit Mode,
if I select one of these,

they are still separated,
so not directly connected.

So now let's try it again
to select this one here,

then with shift the armature.

Press Control + P and click
on With Automatic Weights

Now let's go to Pose Mode and
see what's happening here.

You can see in this case,
it's actually working.

However, it's deforming
the cubes in a weird way,

which I don't want.

I want the cubes to stay as they are

when they will move along with the bones.

And when you have a lot
of cubes and many bones,

it can even happen that some
of the cubes will not even be

included in the rig

when you do this with automatic weights.

So let's undo this and
for our Cubic Worlds rigs,

we need to do it a bit differently.

First, select the mesh.

Then with Shift, select the armature.

Press Control + P.

So until this point,
everything is the same.

However, here we go with empty groups.

What it does,

it will parent the cube
object to the armature.

It will also add the
armature modifier here.

However, all the vertex
groups which will be created

for each bone here is just empty.

So we have the vertex groups,

but no vertices are applied here.

And our workflow will be like this.

We go into Edit Mode.

And by the way, there's
a little helpful thing

for the armature object
in the armature settings

under Viewport Display.

Let's enable the names

so we can see what the
name of each bone is.

And then we know exactly

which vertex group belongs
to which bone here.

Then we go to Edit Mode
of the object here.

With L, I select one full cube here.

Or if we have multiple cubes

which should move along
with a certain bone,

for example, like this.

Let's just do it here so you
better understand what I mean.

And just press L to
select all of these here.

Then I go to the vertex group

which belongs to the underlying bone here,

which is Bone top.

And then all you need to do is hit Assign.

Make sure the weight is set to one.

Then I press H to hide them.

Then I select the next bone.

Go to Bone center, hit Assign.

And then let's do it again
with the cube at the bottom.

Hit Assign.

Then let's press Alt +
H to unhide everything.

And I just hide the cube so I know

which I already assigned
to a certain vertex group.

And in general, this
workflow is much easier

because we don't need
to deal with the weight

and weight painting,

which can be a pain in the butt sometimes.

Let's go back to Object Mode here.

Let's get back to Pose Mode.

And now when I move these bones,

you can see how all of
these cubes will move

along with the bones.

And the cool thing is if I
rename a bone into something else

like Bone bottom 2, for example,

then the vertex group
will also rename here.

And if you don't wanna
accidentally change a vertex group,

you can also lock these,

and you can also reorder
these, for example.

Top should be at the top,

center should be at the center, and so on.

And later on when we
work for our character

and we have a lot of vertex groups,

we can also click this little arrow here

and search for something,

and then only the specific
bone will show up here.

Yeah, and this is how we can deal

with the whole skinning subject
in our Cubic Worlds style.

And now let's learn how we
can apply this knowledge

to our character rig.