Help understanding elements of digital human

Hi

I did try asking this in Polycount’s subforum on Unreal, but I’ve had no acknowledgement, so figured it’d be best to ask here. I’ve recently finished a character model and has the best real-time eyes I’ve made to date, but I know they can be greatly improved for next time. :slight_smile: I decided to export out and examine the digital human head mesh to see how it was put together. There are, however, a few things I’m confused and unsure about, which I’m hoping some could shed some light on.

Firstly, what is this element exactly and how is it used? There doesn’t appear to be anything written about it in the documentation. The material is simply called ‘Eye Blend’ and it rests next to the caruncle.

maya_fvDnHdkSXN.png

Also, how exactly do you set up a flow map for hair? I understand it’s nothing more than the red channel of the hair’s normal map…? The flow map for the digital human is 1K, but it looks to be scaled down to 64x64 and is quite blurry.

Photoshop_j2xUs9o16S.png

I’m still not sure how this even works, even by looking at the material editor. It’s set up under ‘Tangent’. I’m not seeing any difference when I disconnect the node either.

And finally, I’m confused with the Dye Mask. How are these typically made?

That’s all I can think of for now, but I’m sure I’m missing something.

Is this the Meet Mike digital human sample? Epic has put out multiple character rendering samples over the years, if that is the one I’m thinking of then there is a huge documentation page that goes over all the details of Epics approach to character rendering/modeling/texturing techniques.

Oh no, this is the other one in the same project file. The Photorealistic Human:

It goes over the eyes, but I haven’t seen anything related to the Eye Blend in there. Or the Tear Line. And though it mentions the Flow Map, it doesn’t specify how that’s made.

My guess is that it probably serves the same purpose as the Caruncle Blend Mesh in the Digital Humans docs I linked.

I’d recommend you reference the Meet Mike sample instead, as it’s much more recent and higher quality.

Another option would be to just export a MetaHuman, though I think it probably follows similarly to the Meet Mike setup.

Okay. I figured it was the Photorealistic Human I needed to look into as that’s supposed to be more in line with real-time characters for games…? But I didn’t realise the Mike mesh covered those aspects as well, so I’ll look into it. Thanks.