Material bug involving Dual Lobe and Volumetrics?

[Hailey Eliese]

I am trying to render Victoria 8 and it’s looking really weird in both eevee and cycles. the skin is dark, glossy and surrounded by fog.

Using default settings to import:

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[Hailey Eliese]

In addition, Materials using dual lobe is also black in stable version 1.4.1 while rendering with eevee when there are no normal maps.

[Thomas Larsson]

Those settings should produce quite descent V8 skin in cycles, similar to the results in https://bitbucket.org/Diffeomorphic/import-daz/issues/24/i-believe-i-nailed-v8-aka-true-iray-skins. For eevee I’m not sure.

Can you provide a screenshot of the node setup.

[Alessandro Padovani]

Just tested and V8 works fine here. Volumetric skins don’t work in eevee. You may use the full global illumination preset in cycles just to check if it’s a fault in your cycles settings. Please note that volumetric skins use true volumetrics the same as iray does so they don’t work without volume bounces. The settings below work fine enough with good speed though the skin quality is not optimal. For better skin quality you may increase the transmission and volume bounces. Also please note that refractive caustics are needed for the eyes.

Thomas, may be it helps adding some notes in the docs.

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[Thomas Larsson]

Hello Alessandro,

I rendered a closeup of your V8 test file, using the scene setup above + some denoising. There are some weird artifacts at the back of the skull and at the uv seam on the neck. Do you have the same problem?

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[Hailey Eliese]

Oh I see, but that’s a bit annoying for those of us using lookdev to experiment with lighting before doing a final cycles render.

Would it not be possible to merge both the cycles and eevee node setups as a single material each with their own “Material Output” target?

That would allow for greater compatibility.

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[Alessandro Padovani]

That is done to keep materials simple. Usually projects are designed either for animation or games. So the choice of the final render engine is done at the beginning. As for lookdev it’s not good enough for a cycles preview and not useful with eevee as you see yourself. So it’s usually better to use the rendered shading mode with limited samples if you want a meaningful preview.

But that’s just my opinion of course. Thomas may very well decide otherwise.

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[Thomas Larsson]

I think I have found a simple way to switch between render engines without making the materials and the code more complex. The new Copy Materials button copies all materials from one mesh to another. Say that you want to support both cycles and eevee. Import the file twice more with the appropriate import settings, and keep these meshes in hidden collections. Each time you want to switch render engine, just Copy Materials from the cycles or eevee mesh to the working mesh.

If you are concerned about file size, you can delete all vertices of the hidden meshes. They are just needed to store the materials. You can of course use the same technique to change makeup, tattoos, bruises etc. on the fly.