But down that Rabbit hole, you must go.

Victor.Soupday (6/29/2021)

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But down that Rabbit hole, you must go.

It has taken me a while to figure all this out but, consider this character in CC3:


She is of the quality you would expect from Character Creator, but when you export into Unity (I'm using Unity 2020.3 / HDRP Pipeline here) you get this:



Which is obviously awful, Mainly due to the FBX format, which does not support the PBR texture set. (At least not the version of FBX that CC3 exports and Unity imports.). In fact, all it understands is the Diffuse texture, the Specular mask texture (which Unity doesn't actually support), the Opacity texture and the Normals. Which is why it looks terrible, because most of the textures are missing.

The next order of business is to populate the HDRP/Lit materials with the appropriate base textures, of which we have the Diffuse, Mask (named with the suffix '_HDRP' in the files.) and Normal maps.

Here I have plugged all these textures in, changed the hair material shader to HDRP/Hair, and given them some appropriate settings:



(I'm using the eye occlusion texture from the OBJ export to Blender as the alpha channel in an all black diffuse map, for some reason it doesn't come with the FBX export. The tearline material is 100% transparent, max smoothness material with no textures.)

And this is probably as good as it gets with the base textures and default HDRP material shaders, but it all looks flat and lifeless compared to the CC3 image above, particularly the eyes.

To truly recreate the character with all the details and layers and effects of the CC3 shaders, you have to dive into Shader Graph. Additionally we also have the problem that there is no 1:1 mapping of CC3 to Unity. They use different lighting, different shader models, different colour mapping and who knows what else. I had the same problem in Blender when I was making the Material setup add-on for that, the only real solution being to provide enough parameters and controls to the users so that they could make the characters in Blender look like the characters in CC3.

The same is true of Unity, so to achieve similar results to CC3 we need more control over the material shaders in Unity than the default HDRP/Lit and Hair shaders can provide.

The shader nodes in Blender materials and Unity's Shader Graph are very similar. Similar enough that I could reproduce the same shaders in Unity that I made in Blender, even improve on them a bit. And they look something like this:



These shaders are using all the textures for the blend layers, micro normals, normal blending, shadow layers, hair root, id and flow maps, vertex deformation for the eyes and all the parameters to control how each texture is used and layered into the final results. The eyes are refactive with iris depth control and pupil size control. The skin, hair and eyes have min-max remapping and power curve mapping for the smoothness and alpha channels and it has all the controls of the smart hair shaders too.

There's still more work to do on the shaders and they are going to take a serious amount of explaining, but so far, I'm quite pleased with the results.



More to follow when I get the chance...

Victor.Soupday (7/1/2021)

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Well, as to that... The shaders shown here are part of something I've been working on for a while:



It's not entirely finished and this is just for HDRP so far. It doesn't do anything with the Avatars and the bones so there's a ways to go before it's complete. Also it needs to map all the CC3 material parameters to the equivalent for the Shader Graph parameters, it only does a few of them so far. So much like my Blender setup add-on it just works on the materials and shaders for now, but it's coming along nicely I think.

URP and the built-in renderer are going to be a challenge as they have no native methods for subsurface scattering or depth prepass or refraction. It will be interesting to see how much of the quality and detail can be retained for those render pipelines.

Edit: I can go into more detail on how the shaders work, they could do with some explaining.

tantrum (7/1/2021)

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I saw/realized a while ago that shader graph would be the way to go, especially for the new "Smart Hair" system - even in Unity the shader graph shaders for things like HDRP/Hair are more capable than the old property-drawer shaders.

But then by the same token, you'd want to use the original textures and shader parameters (or some variant of them) that are already in CC3 for closely recreating them in Unity, instead of working off the baked textures provided (which would be better suited perhaps for generic / non-hero NPC models and/or lower LOD crowds)?

So at this point I'm wondering if it wouldn't be better to export (as a .json or something) the character meta data for that information and the paths to the textures used in CC3, so there would be some hope/chance of an automated workflow possible in Unity without having to manually match up the values.

tantrum (7/1/2021)

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But then by the same token, you'd want to use the original textures and shader parameters (or some variant of them) that are already in CC3 for closely recreating them in Unity, instead of working off the baked textures provided (which would be better suited perhaps for generic / non-hero NPC models and/or lower LOD crowds)?

So at this point I'm wondering if it wouldn't be better to export (as a .json or something) the character meta data for that information and the paths to the textures used in CC3, so there would be some hope/chance of an automated workflow possible in Unity without having to manually match up the values.

Victor.Soupday (6/13/2021)

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All the facial blend shapes available in CC3 are exported with the characters (the full characters, not sure about the Gamebase or InstaLod'ed characters).

e.g. these are all the blend shapes on the main body mesh:



There are also blend shapes on the tongue, eye occlusion and tearline meshes, as well as on the smart hair: beard, moustache and eyebrow meshes too. Everything that takes part in the facial animation has the requisite blend shapes.

tantrum (7/2/2021)

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I noticed the blend shapes, but it also seems that a lot are just dumped inactive into the mix.

I would have liked the groups to be documented if some only come into play under certain conditions, or removed if they play no part in the piece at all.  To that extent I created this issue a little while ago; I would be interested to hear your thoughts:
Smart Hair assignment of brow blend/morph shapes (name and quantity) - FeedBack Tracker (reallusion.com)

Personally, I don't like having to go through them one by one and guess or try to figure out if they are usable or not.