Hello community. In this video I want to
show you how to add a custom morph target to a metahuman head in blender. I will talk a
lot about the level of detail. I think it is quite important especially for games, while in
almost all tutorials that I’ve found this topic was ignored. You can generate LODs in unreal
editor, but generated are not so good default If you are OK with keeping only the
lowest LOD, things will be much easier So, let’s get started.
I use a metahuman demo project, metahumans and create project open editor Click quickly add to project, quixel bridge, don't forget to sign in, cause otherwise
you will not see your own metahumans. Metahumans - My metahumans. Choose which
one you want to import. This one has been downloaded previously. So click download if it
is not downloaded yet, I only need to click add. If there is a first metahuman of the project you
will get a few warning messages about missing plugins. Just enable everything and restart
the editor. Demo project is preconfigured, that's why I didn't get these messages.
And as for source content I don't import source content
So close everything. In content we have “Metahumans”, and here folders for each
metahuman of the project. My metahuman is called Vivian. So I go to Vivian. Face. And here we have
skeletal mesh called Vivan underscore face mesh. Let's duplicate it. It will be handy in future.
Duplicate. I will call it SKM_VivianFace. OK. Open it. The first problem. There are two slots with
the same name. One is for saliva and another one is for eye edges. It will be better If we
will replace one of them. So I browse to this. Duplicate material instance. And I will call it MI_saliva_Inst and replace the
default material with this new one. Now we can export the FBX.
Navigate to metahumans, Vivian, face, SKM Vivian face, asset action and export. And I will save
it at my desktop.Default settings are good. Before importing FBX in blender you
need to do one very important step. You need to install Autodesk FBX
Converter. I have it installed. Open it. Drug and drop exported
file here, click convert. If you will skip this step all material slots,
and all existing morph targets will be missing In Blender we need use this new
file from the folder FBX2013 Here this one so we can close the application and
open blender. Let's clear the scene. First thing we need to do we need to set up correct unit
scale. Goto scene properties unit and 0.01. Ok. Now file import FBX find on the
desktop. In folder FBX2013 find this file. Default settings are almost OK.
As for the orientation. I prefer to follow the next simple rule: use manual orientation and keep
in mind the axes when importing the mesh, then use the same orientations for export. This way axes
orientations will be the same as in the initial FBX. I will set here forward Y, up Z. Import.
Finally we can create new shape keys. The best way is to create shape keys
for the lowest LOD and then transfer them for all further LODs. So I will
hide everything except the lowest LOD. And go to object data properties, and create
new shape key here. I'll call it CustomMorph. And pin it. Now we can go to sculpt
mode and sculpt whatever we want. As soon as it’s done we need
to transfer all created shape keys from the lowers LOD to other LODs.
I'm going to use my add-on for it. The link is in the descriptions. You may do it manually or use
any tool you are comfortable with. I go to object mode. Unhide everything and select all LODs except
the lowest. At the end I select the lowest LOD. And wind my addons menu at N-panel, tools, here
this menu. Click transfer by list. And initialize list as unchecked. Here. Uncheck all. It will not
transfer all LODs and we can find at the very end CustomMorph. And I check it. You can check a
few morph targets if you have created a few. Now final step. Transfer shape keys. Let's check the
result. Unpin it. Select the lowest LOD and try to change value. So as you see
all LODs are also changed. So, works well. Now obviously we want export
the model back to Unreal, but there is problem. If we do it right now, at
the end we will get this. “Incorrect LOD video”
It happens because the unreal engine processes everything
like it is a single mesh, while we have a few separate levels of detail.
So we need to change hierarchy to provide more explanations to the unreal engine
exporter about what we actually want. But before we fix hierarchy you should know
one fun fact. An index at the end of LOD mesh name here means nothing. Order of LODs is
defined only by the object creation time. So even with the right hierarchy, with 99
percent probability the order will be wrong. To fix it we need to duplicate
objects in proper order. I have a script for it
Let's select all meshes. And paste script. The script just creates a copy
of each mesh in correct order. So run the script. And see here. Here we have initial objects
marked as outdated. We need to delete them. And here we have the objects
created in correct order. Let's fix the hierarchy. We don't
need this empty. Unhide everything. This empty is handy
Now we need to parent all LODs meshes to the armature. So
select all of them. at the end select armature. Click control + P and choose armature
deform. It is very important. Armature deform. then parent the same meshes but to the empty.
select all of them select empty Ctrl + P. Object. At the end select empty only select
armature and parent to object. So at the top of hierarchy should be
armature. After this should be empty. And under empty should be all LOD meshes with
armature modifier. Here armature deform modifier. Hierarchy is OK. We need to select the empty. object properties, and add a new custom property.
type should be string. Property name “fbx_type”. Value “LodGroup”. L and G are capital. That's it.
Now select everything. All armature, empty, LODs. Double check. All of them should be visible and
should be selected. Go to file. Export. FBX. Start with defaults. Selected
only. Here. Should be checked. Now it is a good time to remember axes orientation
we have used to import. So forward Y, Up - Z. Geometry. Smoothing should. face.
Uncheck apply modifier, cause as it stated here, it “Prevents exporting
shape keys”. It should be unchecked. Armature. Uncheck leaf bones
and uncheck bake action. Now we can save it somewhere. Here. On my desktop.
I will save it as SKM_VivianFace_Morph. Export. Now go back to unreal engine.
content folder. And open the skeletal mesh. Now scroll down.
At the end we have Import settings. Expand mesh. Check import mesh LODs. Check it. As for transform. we don't need
this transform. So all translations, all rotations should be 0. Scale 1.
And set file path, source path. Find the final mesh from the blender SKM
Vivian Face Morph. Open. Save it and. Content. Find the icon of this mesh. Right click.
And reimport. It takes a long time. Unfortunately. Now we need to set proper asset material here.
Select the same as in the left column. Done. Let's check what we have. Scroll up. So.
Number of materials is the same as in the initial mesh. 15 materials. And let's go through
all LODs. LOD1. LOD2. LOD3. Something strange. We need to fix it. LOD5 and LOD7. So we need to
go through all LODs and check materials for them. Let's check custom the morph target. It is here. And it works. Now. The initial
mesh will be very handy. Open the initial mesh. Go to LOD sections. and check all materials
of these two meshes. And compare all of them. Teeth, saliva, left eye, right eye, head teeth,
saliva, left eye, right eye. Eyeshell, eyelashes, eyeshell eyelashes, eyesell,
eyelashes, eye edge, and cartilage. So for the zero LOD everything is
OK. Let's go to the second. LOD1. LOD1. Sections. Here LOD1 shader. Here, the first problem. At LOD1 as a skin shader
we have the lowest LOD shader while here should be LOD1 shader shader. All other looks good. Let's go to LOD2. Sections. LOD2 shader,
teeth shader, saliva shader. LOD2, sections. The same
thing. Wrong skin material. Here should be LOD2 shader. Teeth shader,
saliva shader is ok. Left eye, right eye, eye occlusion, higher LODs and lacrimal fluid inst. Eye
occlusion. Here we have lower eyelashes shader. So we need to check. Here should
be eyelashes HiLOD shader shader. LOD3. This creepy one. Sections. The same
thing. Skin material is not correct. LOD3. Teeth shader. We don't have saliva, so here
should be section 2 left eye, section 3 right eye. Left eye, where is the left
eye. Left eye. Right eye. Eye occlusion. eyelashes. and eye edges. Eye shell. eyelashes higher LOD and eye edges. Go to LOD4. Also creepy. LOD4. Sections.
head, teeth, left eye, right eye and eyeshell. Wrong here. LOD4. Teeth ok. Left eye, right eye, and at the end eye edges. Looks
nice. LOD5. LOD5. Sections. The same thing. LOD5. Here correct five seven shader shader. Teeth
shader. Left eye shader, and right eye shader. As for the further LODs it is the same. So now everything is OK. So we have
metahuman with all LODs with proper materials and with the extra morph target.
And the morph target works with all LODs. And animations also works.
Let's check preview animation. Now the head works well as
a single thing, but it still does not work well with the other body parts.
Let me show it. Go to Vivian folder. To blueprint. And I want to replace face skeletal mesh
component here with the new one. SKM_VivianFace. And something goes wrong with hair. It is a woman so obviously we don't really
need to cade about mustache and the beard but we still need to fix four grooms. eyelashes,
fuzz, eyebrows, and hair. Let's start with hair. Here we have the problem. The groom
is bound to the previous mesh. We need to create a new binding for the
new mesh. So browse to the groom asset. Right click on it. Crete binding. Select target skeletal mesh. SKM_VivianFace.
Conversion. As the source skeletal mesh select initial vivian face mesh. And create new binding.
Nice. Save it. Let's go to VIvian blueprint and choose another asset. Now it works well. And let's do
the same for all other grooms. Now everything works well and you can control
the morph targets from blueprint or from code. Let me show it. Event graph. I will set a morph target for face. Morph target's
name is CustomMorph. Value is 1. Compile. And for demonstration I want to replace
the default female character with my new one. Here I need to go to the content drawer.
And place the character on the scene. Now we can to the sequence,
metahuman sample sequencer. Go to characters, Ada, right
click and assign another actor, Vivian. Ok. And finally enjoy the result. If you want to see more videos like this one
click thumb up and don't forget to subscribe. Let me know if you also want to see similar
video about metahuman body customization. Thank you for watching.
Bye-bye
