Geometry shell tears losing color

[Viktor Vošček]

Hello,
I applied this tear pack (+ultimate skin moisture) on my character, but when I import it into blender the tears lose their color. USM looks like it got imported correctly. The tears dont have any color texture, you can adjust that in the surface settings instead, so I’m guessing it has something to do with the node setup. I’m attaching a screenshot from both programs.

I’m on the latest commit.

[Alessandro Padovani]

We had to use some tricks to make USM work in blender since refractive shells weren’t supported, see #558. Will look at it, it’s probably USM + Tears that doesn’t work. I mean Tears alone may work fine, as well as USM alone.

[Thomas Larsson]

I tested the tears alone, and it was a disaster, because some mask texture should be inverted. That was fixed in the last commit.

[Alessandro Padovani]

Commit d7b4513 works fine enough here. The red tears get pale for some reason. Will see what I can do but refractive shells may be hard to get right.

[Viktor Vošček]

Thank you for the response, I updated to the latest commit (completely deleted the outdated version), imported my character again into a clean blender file, but I’m getting the same result as before. I also tried importing the character without USM (made a copy of the DAZ file and completely removed the USM shell) without any success. I did not do any corrections.

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[Alessandro Padovani]

Hi Viktor, below what I get with the test scene tears-black.duf where I applied the “mascara dried a“ preset. First iray then cycles. It can be improved but works fine enough here. It’s commit d7b4513 version 1.6.1.0713.

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[Alessandro Padovani]

test scene for tears

[Viktor Vošček]

Alessandro,

I tried importing your tears-black.duf scene, and subsequently applied the ‘mascara dried a’ on my character, both successful. However when I apply ‘mascara wet a’ it still imports as a transparent liquid. I guess the wet and dried versions work differently.

[Alessandro Padovani]

Ok, will look at it and let you know what I find.

[Thomas Larsson]

You can darken the tears with Advanced Setup > Visibility > Set Shell Visibility. Normally you use that to turn off the shell in scenes where she is not crying, but cranking up the visibility to a value > 1 intensifies the shell.

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[Thomas Larsson]

I just added an option to keyframe the visibility values.

[Viktor Vošček]

Hi,

Thanks for the tip, I came across this feature when I was reading the documentation but I never though of setting it to a higher value.

It works great for the dried mascara variations, however when I try increasing the visibility for the wet variations it only increases the displacement, and they are still transparent (as well as the wet smudges around the eyes)

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[Alessandro Padovani]

Yes didn’t look at the wet case yet, I’ll let you know.

[Alessandro Padovani]

Ok we have a couple of major issues here. I'm going to separate them for better handling but this will take a while.

LAYERED IMAGES. The first issue is that layered images are bad. I don't know how much Thomas is into this but I understand that the support for layered imges is currently limited. We need to resolve this and get a more general and robust support for layered images. See #780.

SEMI-REFRACTIVE SHELLS. The second issue is that the wet tears use a semi-refractive shell, that is, a shell that's 50% refractive or so, this way the diffuse channel is partially visible. The actual support for refractive shells is limited and designed for 100% refraction. See #558.

[Viktor Vošček]

Allright, I understand that it’s not so simple to recreate shells because Blender doesn’t have a direct counterpart, and so the support for shells is limited.

[Alessandro Padovani]

The trouble is just with refractive shells, non refractives work fine. I’ll work on this and I’m confident we can improve at some degree, but needs some time.

[Viktor Vošček]

I’ll keep an eye out for updates, good luck and thanks for the all the help so far.

[Thomas Larsson]

Rendered with latest commit. Now the tears are almost too dark.

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[Viktor Vošček]

Updated to the latest commit and I think I’m getting a different result from yours, maybe there is something wrong on my side? I used the ‘mascara dried a’ material preset. I left the shell visibility on the default setting for this screenshot.

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[Alessandro Padovani]

That’s because LIEs use srgb while regular textures use non-color. You can go to the shell and either change to srgb or increase the influence. Technically it is correct for alpha maps to be non-color, but in this case it seems daz uses srgb, not sure how we can tell the difference.

As an anticipation I believe I also got semi-refractive shells, but I have to sort things for Thomas and no time right now. Will probably update tonight when I get back home or tomorrow morning.

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[Viktor Vošček]

Okay great, this seems to work.

Happy to hear about the progress on refractive shells, no need to rush though

[Alessandro Padovani]

Thomas did a great job with the latest commit 082575c and now refractive shells work fine enough. We may mark as resolved.

There is still some difference with iray and sometime we have to adjust the shell influence or the fresnel IOR inside the shell. This is because we use some tricks with add shaders for refractive shells so unfortunately some approximation is to be expected. But will update if I find something better.

[Viktor Vošček]

Finally got around to test the newest commit, and it works great. Thank you for the fast response and fix once again.

Here is a quick import of the ‘tears dripping a’ variant (I also tried different variants) + ultimate moisture shell. I’ll definitelly tweak it further along as I progress with the scene, but the shell itself imports correctly (as you mentioned, not 100% accurate).

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[Viktor Vošček]

Refractive shells did not import correctly. Fixed in the commit 082575c