We’ve recently started to work with an incredible new app available through Unreal Engine. We’re talking about MetaHuman Creator, the newest thing in digital human creation, and we want to tell you about our experience working with this revolutionary new tool. “Cool” as an adjective doesn’t really cover what it’s capable of.
We first heard about MetaHuman Creator earlier this year when we had a meeting about face animation with a company called 3Lateral, who in 2019 were acquired by Epic Games. At the time of our meeting, they had not yet launched this new project they were working on, but they were kind enough to show us a sneak peek of what was to come, and we were immediately blown away. We knew right away that a tool this amazing was something we had to get on board with as soon as it was launched!
What is MetaHuman Creator?
You can check it out for yourself on the Unreal Engine website, but here’s a brief rundown of what the program does, in our own words. It’s a web-based program in which you can create human faces based on a selection of digital faces in their database. You blend, sculpt, and push the look according to the design you want to achieve. There are some rules about what you can do, but it is very flexible, and you are able to create remarkably unique characters. Once you are done, you export and get a face with ready-made blend shapes (of which you need hundreds), and they are unbelievably life-like. It takes next to no time and there you are with a fully realized character for your game!
We have created our own workflow around the way we use MetaHuman Creator. We utilize the blueprint setup and head models from MetaHuman, while using our own custom body rigs.
So, let’s talk about why we use MetaHuman Creator and how we have overcome some challenges that we’ve found throughout the process.
Why use MetaHuman Creator?
There are several reasons using MetaHuman Creator is a smart move for any video game.
- Our aim is that the graphics of our game are as realistic as possible. MetaHuman is a solution that makes fulfilling that goal entirely possible. It gives us realistic characters, both in looks and the way they deform when animated.
- MetaHuman allows us to work rapidly in producing and making changes to our characters. This is time saved in the technical processes, while giving us more time to think about design.
- By using MetaHuman we have a consistent quality for all our characters.
- The controls for facial animation are abstracted onto a common control board, meaning we can easily share facial animation between characters.
- And it is free to use in all your Unreal Engine projects! What’s not to love about that?
We gave handmade characters a try in the beginning of our process, so we know the difference it makes in terms of time, cost, and ending up with lifelike characters when we choose to use MetaHuman Creator.
Some challenges we’ve found
MetaHuman Creator has a limited range of clothing available and they’re obviously not suitable for historical characters.
So, we needed to come up with a method of using custom body rigs with the MetaHuman setup. An important factor was that the face has its own skeletal mesh, separate from but constrained to the body skeletal mesh, so we could replace the body with one we created ourselves. However, without making the necessary adjustments to the rigs, we would end up with deformation issues.
In order to get clean deformations, we have to preserve a group of bones from MetaHuman’s body skeletal mesh over to a new skeleton. These bones are the points of reference the head constrains itself to and are now required in all our rigs.
Later, when the character is almost complete, we tick “Use Mesh Pose” from the “Copy Pose From Mesh” node inside the character animation blueprint. As long as we do these two steps, we avoid deformation issues. Apart from this we have the flexibility to customize each rig as needed.
Performance is another challenge we are facing now. The MetaHuman characters are performance heavy out of the box, despite having a great level-of-detail setup.
The number of material IDs contained within the MetaHuman heads is another current performance challenge. Currently they hold 14 material IDs, which are each an extra draw call on the game engine. Having a crowd of characters with more than 14 material IDs each is a significant cost on performance, so ideally, we want to find a method of reducing that number to closer to 5 per character.
So, we are still working through a few hitches, but none of them are insurmountable. Finding the solutions is part of the learning curve of using a new product. You can look forward to the day you see a crowd of realistic, historical MetaHumans walking around Jerusalem and interacting with one another. Until then we here at Bible X will continue to learn, create, and develop to make that a reality!