All language subtitles for CustomMetahuman_4.2.mp4

Now we will take our particle systems
and get them into Unreal Engine.

I will show you how to import the hair,
how to attach it

to your metahuman character
and how to change the behavior

and look of the hair.

Before exporting,

let's have a quick
look at what we actually have here.

We have first created the top hair,
which consists

of a number of different planes
that function as hair emitters.

Then we have the head mesh
that has 4 hair particle systems:

The ShortHair, two breakaway hair layers

and the flyaway hair.

One thing to pay attention to
is the number of children.

I sometimes forget to set

the render amount to the same number
that I used for the display amount.

So if you see discrepancies in the look of the hair

between what you see in the viewport here
and what you get in Unreal Engine,

it might well be that your render amount
has not been adjusted.

And second, make sure the Show Emitter checkbox

is deactivated for the head and the planes.

Otherwise, you will export the emitters
along with the hair.

When this is all set,

we can now select all emitters,

which is the head mesh
and the planes for the top hair,

then go to export and choose Alembic.

Let's go through the export settings.

First of all, the scale.

You might have already noticed
that when you import

your OBJ character mesh from Mesh Morpher,

it's scale is very big.

It's actually 100 times bigger than the normal size.

So when we export the hair,
we can leave the scale at 1.

If your head mesh is scaled to the normal size,

you might have to set the scale to 100.

This setting is no deal
breaker, by the way.

You can always change the transformation
of your assets in the import settings in Unreal.

If the scale or rotation
of the imported asset is off,

you can simply change the transformation settings

and re-import.

Next, we don't have any animation here,

so we set frame start and end to 1.

A very important setting is this part here.

Also, there is a small difference
between Blender 2.9

and Blender 3.0 for these settings.

Let me quickly show you what those are.

Let's start with Blender 2.9.

Your options here are

"Selected Objects", "Renderable Objects"
and "Visible Objects".

We always want to check Selected Objects,
but there is a difference

between what happens when you choose
either of the other two.

I will export both options
and then re-import them in blender.

If you select Renderable Objects,
for some reason, Blender will export

the emitter objects - so in our case,
the head and planes - along with the hair.

Only the Visible Objects option
does what we need it to do and exports

the hair only.

In Blender. 3.0,

we don't have the Renderable Objects option anymore.

So we check Selected Objects
and Visible Objects.

And the neat thing in Blender 3.0
is, that they introduced

this option here, where you can select
which settings you want to use.

This refers to your settings and the
particle details panel.

Here, you can choose either one,
but just make sure that the corresponding

"Show Emitter" setting for the hair is deactivated.

Since I created my hair in 2.93,
I will export with these settings.

Selected Objects and Visible Objects ticked.

We can leave all the rest of the settings on default.

You see here at the bottom
that the hair particles will be exported

We can now open up
our Unreal Engine project.

First we need to activate the plugin
that will allow us to import

groom assets.

Open the plugin settings
and search for Alembic.

Activate the Alembic Groom Importer plugin,

and restart the engine.

Now let's create a new folder for the hair

and drag and drop our exported
alembic file into it.

You should see this import dialog window.

in case you see something different,
like the normal alembic import dialog,

then you need to look into your export
settings in Blender again.

It might be that you have exported
the head mesh along with the hair.

Depending on the orientation
of your mesh in Blender,

you might need to adjust
the transformation settings here.

I will leave them on default for now,

to show you how to adjust them after importing.

Now let's open up the hair asset.

Everything looks good so far
except for the rotation.

If we drop the asset into the level,
we can check what we need to adjust.

So apparently we need to rotate it along
the Z and the X axis

Also, if you look at the hair closely,
the part where I removed some hair

for the scar on the left temple,
seems to be on the right side.

So we also need to flip it.

Rightclick on the hair asset

and select Reimport With New File.

Now let's set the X rotation to 90

and the Z rotation to -90

and the scale to -1 on the Y axis
in order to flip it

and click import.

Yep, the orientation is now fixed

and we can proceed with attaching the hair
to the character.

For this I will open up the Hero blueprint
and in the blueprint components

let's select the hair component
and under Groom,

search for our imported Hero_Hair asset.

Uh, that's not how it's supposed to look like.

So, the reason why it might look clipped
and all weird, like in my case,

is that the settings for
the hair were pre-adjusted,

especially the hair clip length
has something to do with it.

Just click on the little arrow
here to reset the value, and boom,

we now see what we would expect to see.
Although the hair is now

part of the character blueprint, it is not
actually attached to the head yet.

The fix is quite easy.

Just right click on the hair asset
and create a binding asset.

Choose your head mesh
as the target and click Create.

Back in the blueprint,

simply assign the newly created
binding asset in the groom settings.

Now the hair follows along
with the character movements.

And not only that, it also responds
to the facial deformations.

Right. Now, let's have a look at the options we have,

to adjust the look of the hair.

Open the material instance
from the blueprint and play around

with the customization options,
the metahuman hair shader provides.

For example, you can change the saturation
the melanin concentration, whiteness,

or even dye the hair in any color
you want.

The hair asset itself also comes
with a lot of customization options.

In Strands tab, for example,

you can adjust the hair thickness,

root and tip scales, shadow density
and other things.

Since groom assets are quite heavy
on performance,

You can even quickly set up
an LOD system for your hair.

In the LOD tab,
you can click on the plus icon

in the top right corner.
Unreal will automatically set up reduction settings

for the hair strands for each additional LOD,

which you of course,
can also adjust to your liking.

Now, let's check the LOD system
in the viewport.

Select the LODsync component,
and instead of forcing LOD0,

set it to -1,
which will activate the Auto-LOD system.

If we move away from the character,
you see how our hair gets reduced,

using the LODs we have just set up

It seems that apart from the hair, there are
a couple of weird issues going on

when LOD1 or higher are activated,

which we will need to fix.

First, the textures on the head disappear

as soon as the character goes to LOD1.

And second, the beard disappears
quite quickly, which looks weird.

The reason for the disappearing textures
is that in contrast to the body,

the head actually uses different
material instances for each LOD.

So let's fix that first.

Open up the head mesh and pick LOD1.
For the first material slot

choose the main head shader
instead of the LOD1 shader.

Then go through all the other LODs,

and repeat the process.

Alright.

The disappearing texture is now fixed.

For the beard:

Select the beard component in the
blueprint and open up the groom asset.

in the LOD tab,

you will see that for some reason
the beard is set to non-visible for LOD2

and higher, and the geometry type is set to cards.

Let's change that.

Activate visibility
and set the geometry type to strands.

Yes! Now everything is fixed
and our character is finally complete.

Well, guys, this concludes
the first part of this course.

You should now have a solid understanding
of the whole workflow

of customizing a MetaHuman character.

In Part 2, we will look into the pipeline

of creating clothes and accessories,
which is not necessarily specific

to metahumans only,
but can be applied to any character.

We will also look into video production
using metahumans.

We will set up a retargeting system,

create an animation sequence
and render a short video.

And finally, I will show you how to set up
a third person player character

with a metahuman
and custom locomotion animations.

If you have any feedback, please let me know.

I hope you enjoyed the content so far
and see you in Part 2 of the course!