MetaHuman Creator

The easiest way to create MetaHumans from scratch is MetaHuman Creator (MHC). Currently (June 2023), it's still in beta and you need to request early access. Once you are granted access, you can access MHC through a web application available at https://metahuman.unrealengine.com/. Because it's a web app, you don't need to install anything (but you do need an Epic Games account).

In the MHC app, you can create new (or edit existing) MetaHumans, which you can later download and use in Unreal Engine. You can only create a new MetaHuman from an existing "template" MetaHuman. After selecting a template, you can change its static face or body attributes, like skin texture, hairstyle, and clothes. Note that (unlike the GFG), most of these attributes are not parametric in the sense that they cannot take on continuous values; instead, they are often categorical (e.g., you have seven different shoe types to choose from).

Also note that you can only change the static attributes of your MetaHuman; although you can preview some preset movements (e.g., "face ROM", "body ROM", etc.), you can only endow your MetaHuman with specific movements in Unreal Engine.

MHC is not the only way to create MetaHumans; in fact, you can create MetaHumans from your own 3D face meshes using the Mesh-to-MetaHuman plugin, as described here.