For the love of MetaHuman…ity….(part1)

This is just info gleaned from publicly available sources (mainly UEFN and Epic documentation)

I’ve spent some time beating my head against this so I’m structuring this post as the one I was looking for and couldn’t find, so here we go.

Basics:

If you want to mess with Metahuman stuff in Maya…

• Install Unreal (I’m on 5.7.4)
• In the options for Unreal install make sure you have Metahuman Creator Core Data installed. You can set this on the little down arrow next to your Unreal Install in the Library of the of the launcher.

You need the Creator Core Data (Unreal will give you errors if you don’t have it and you try doing Metahuman work)

• Install Metahuman for Maya (Fab store). That gives you the Maya plugin you can follow the documentation to install.
• Start an Unreal project

Project and Plugins needed

Dead Ends:

• Epic’s DNA Validation Repository | Was hopeful this was going to get me some basic DNA data initially but it did not. It’s for more heavy duty Metahuman stuff. Just getting the core data installed in Unreal was the progress blocker here.
• Unable (so far) to get joint facial to play as joint animation on a Fortnite character. No problems on custom assets. I think there’s some masking with the head asset but that’s just an assumption. Animation from Maya is easy and there’s a nice tutorial on getting it from Unreal to Maya.

Really helpful bits:

[embed]This dev has a great github link as well. Give them a follow

Getting Cool bits:

• UEFFN Animation Project — It has control rig and face variants (basic and metahuman facial control rigs for Fortnite characters)
• UEFN Stand up project — There’s a stand up routine island with some other neat content that might be helpful.

Feature Examples to look for in UEFN’s project browser

Metahuman for Maya Install

Few hiccups — mainly had some pathing issues because I wanted to install to my own project dir structure. The short answer for the solve was to make sure I did all the paths — mods, plugins for the Maya.env

TECHANIM = D:/MYPLACE/Maya/plug-ins
MAYA_MODULE_PATH =   %TECHANIM%;
MAYA_PLUG_IN_PATH = %TECHANIM%;

First Character assembled from DNA files from Unreal

Learnings the Metahuman/Fortnite Setups

Some of this is just interesting. I’ve done a lot of facial rigging over the years so digging in to some of the highest tier stuff people are doing these days is pretty interesting to me. Most of my last 5 years was mobile level facial so pretty low counts

The full Metahuman setup is very dense. 846 joints go in neck and above. This is an extreme level of joints. Full body count is 1212 Caveat, every head doesn't use all the joints. All the LOD’s are onthe same skeleton.

• Lod 0 — 639 (blendshapes as well)
• Lod 1 — 491
• Lod 2 — 343
• Lod 3 — 254
• Lod 4 — 79
• Lod 5 — 65
• Lod 6 — 39
• Lod 7 — 28
• They use geo controls instead of curves. My guess is because that’s easier to handle in the game engine than curve data. Geo has long been solved.
• Joint poses live on CTRL_expressions Haven’t sorted how this correlates in setup in engine yet. It’s on my list of things to solve eventually.
• Fortnite facial rig is 26 joints. And it doesn’t seem like they increased the count when they moved to the metahuman control rig style. I’m guessing it was more a consolidation idea and to resuse animation.

This is pretty handy for getting the joints of a skincluster

Getting Metahuman Facial from Maya

This was simpler than I thought.

The Fortnite Facial Rigs

“Old” Fortnite facial control rig (Animation Island)

Metahuman Fortnite Facial Control Rig (Animation Island)

Is not the full metahuman facial rig

• Drops ~77 controls
• Adds 11 + controls
• At some point they switched from an older facial rig to one that is much closer to Metahuman’s though not exact. Some characters in UEFN work with one, many with the other. Easy to tell as if you drop one on an asset and it doesn’t move the face, try the other control rig.

Few odd name changes from the full Metahuman setup to the Fortnite one

• tongue wideNarrow >> wideNarrow
• tongue move >> tongue
• tongue bendTwist>> roll

Setup

• Your Fortnite Metahuman rig will need to match so you’ll need to duplicating and or rename the controls to match Fortnite’s
• You can export some anim from the Fortnite or just manually look at the names in UEFN

Export

• Select the existing facial controls object set created by the Metahuman asset builder
• Export to an fbx
• Doesn’t seem to need to be baked

In UEFN/Unreal

• Add the metahuman control rig to the sequence
• Import the fbx (use the control mapping)

Metahuman facial rig on one one of the Fortnite characters

I made a simple range of motion script in Maya to test some data and it worked fine.

That’s good for now. Still exploring and imagine there will be a part 2.