All language subtitles for CustomMetahuman_6.2.mp4

Alright, let's make a retopologized mesh

in Marvelous Designer.

I will show you two options
to create a low poly mesh in Marvelous.

The first is an automated
remesh operation.

And the second is manual retopology.

Although "manual" always
sounds like the more inconvenient option,

you will see that it is actually
a more efficient and clean approach.

So here's our high poly mesh,

and we need to create a low poly
clean topology on top of that mesh.

Let's open up our Marvelous project.

Before doing anything to our clothes,

I want to make another version
of the project file,

so I don't lose the original mesh
in the process.

We can now select all patterns
and remesh them.

This will change the triangulated mesh
into a quadrengulated one.

The resolution of the new mesh
or the number of polygons

will depend on the particle distance
that we used for the cloth simulation.

Since we want to actually
reduce the poly count and not just convert

triangles into quads,
let's set the particle distance to 10.

Now we can click on "Remesh"
at the bottom of the Properties panel,

and boom! We have a nice looking mesh with quads.

Let's export it and have a closer
look at the topology in Blender.

At a first glance,
the mesh looks quite okay,

but if you look closely,

especially at the seams,
the topology is not really clean.

And this can create problems.

For example, you can't select edge loops
because the edge flow is broken at the seams.

And if you apply a solidify modifier,

there will be some ugly artifacts.

But you could take this
as a starting point

and then begin
to clean it up in Blender,

by deleting edges, merging vertices,
and so on.

There is also a function in Marvelous
Designer called "Remeshing to Retopology",

which will create a retopologized version
of the new quadrangulated mesh.

Now you can also do the cleanup here
before exporting the mesh to Blender.

But in my experience,

cleaning up such a mesh takes more time
than doing it right from the beginning.

So although remeshing can be useful in some cases,

it is a rather inefficient solution,

if you want to create clean topology.
A better and faster way is to use the retopology tool.

If you click on the retopology icon
in the 2D pattern window,

you get three options: "Edit Topology",
which is the tool to move or delete

vertices and edges
after you've created a new topology.

Then we have "Create Topology"
and "Patch Topology".

With "Create" you can manually place
vertices and create faces one by one.

With "Patch" you can quickly
make whole patches of topology.

Let's do this.

For each edge, you can select
the number of subdivisions before clicking,

but you can also change
the number of subdivisions for each edge afterwards.

Ctrl-click on the edge and
change the subdivisions to your liking.

Then click "Create" to convert the patch
to topology

The marvelous thing in Marvelous Designer

is that it automatically gives you indications
on the optimal placement of vertices

on all parts that are sewn together.

For example, the pants are made up
of four pieces, right?

If the front and back piece
have the same number of vertices

along the sewing line,
we get clean edge loops around the leg.

If the number of vertices is different,
we will get bad topology.

So we would have to count the number
of border vertices on each cloth piece

and create appropriate counterparts
on the neighboring pieces.

Marvelous already does the job for you and creates so-called
ghost points on the opposite sewing lines.

This is tremendously helpful.

All we need to do now is to make sure

that we follow those indicators
when creating topology on the next pieces.

For cloth patterns
with a lot of curves and corners,

we can go step by step.

The patch topology tool only works
if the patch section is triangular or rectangular.

So we can't create patches
with five or more angles.

For cloth pieces that are linked,

Marvelous will automatically create
a mirrored topology on the counterpart.

And make sure all vertices
are touching the border,

and pull them with the Edit Topology tool
if necessary.

Otherwise there will be missing
ghost points, which might mislead you,

when you work on the neighboring patterns.

Pro-Tip: Use rather large polygons

when working on retopology and increase
the subdivisions later when you are done.

This will accelerate the process and help
you avoid mistakes like miscalculating

the number of border vertices.
When you have finished all patterns,

right-click and select "Add All Division"
which will subdivide the mesh.

By the way, what we have here
is just a virtual topology,

which you can only see
in the retopology mode.

To actually create a new mesh, right-click
in the window and choose "Remesh All".

Then move the new patterns to the side,

so we can select them for export.

Now we can import the OBJ in Blender
and merge the clothes at the seams.

I'll use the "Select non-manifold"
and "Merge by distance" approach.

You can increase the merge distance
to get more vertices to merge,

but be careful and check your mesh.

If you set the merge distance to high,
it might merge vertices,

that are not supposed to be merged.

Now we can add a solidify and subdivision
modifier to get some thickness.

With our new clean quad-based topology,

the modifiers work like a charm.

If you have clipping issues, move
the mesh in edit mode,

or use the inflate brush in sculpt mode.

Let's fix the arm wraps, for example,
and then separate the cape

from the clothes mesh and inflate
those areas slightly to avoid the clipping.

Let's quickly compare the two objects.

On the left is the model with
the automatic remeshing, and on the right

our retopologized mesh.

We have only about 5000 faces for
the whole outfit without the modifiers,

and the remeshed model has about 33,000 faces.

What I am not yet happy with

is that we lost the more prominent folds
in the lower part of the pants.

Yes, we will bake the folds
from the high poly model

into the normal map,
but I want them to also be

physically visible in the silhouette of the character.

When you look at the mesh closer,

you will see that the folds are not real,
so to speak.

To increase the number of faces is quite easy.

In Marvelous Designer,

let's go back to the retopology tool.

Here, you can right-click on any piece
and select "Add Division",

which will divide every face into four.

Just make sure that you do that
for all pieces that are sewn together.

Let's create a new mesh from that
topology again,

bring it into Blender and merge the seams.

This looks a lot better now

and we don't have a significant increase
in poly count either.

So this is something
you will have to test on your own clothes.

It's a decision on how high you are
willing to go on the poly count, vs.

how well the new low poly mesh fits
the high poly one.

I'm quite happy
with this version of the low poly model.

Let's rename it
and move it into a new collection.

Then I'll duplicate all the props
and accessories that we modeled as well

and move them into this collection.

At this point, I just want to check

if we need to create low poly
versions of any of the items.

For things like the medallion, bracelet
or other minor details,

I will just use the Decimate modifier
and not bother to do any retopo.

This will do just fine.

The helmet has a quite dense topology.

However, this item will be a static mesh
in Unreal Engine and we can use

Nanite for static meshes.

So no need to create a low poly
version either.

All in all, the complete outfit has
about 140K faces

or 270K tris, which is totally within
the acceptable range for a mid-poly clothes asset

for our MetaHuman.

So this is basically it.

One final issue
worth mentioning is the UVs.

We have created a UV layout
for the clothes before.

However, after retopology, the new mesh
is back to the original 2D layout,

and we will need to arrange the cloth
items into the UDIM tiles again.

You could do that in Marvelous before
exporting the low-poly mesh to Blender.

But since we have already done

a lot of cleanup work and we'll have to
UV unwrap the modeled pieces anyway,

we can just also do that
directly in Blender.

But this is a topic for a bit later.

Next, I would like to show you
how to do retopology in Blender,

in case you don't use Marvelous
to create your clothes items at all.