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Chris Bruin avatar image
Chris Bruin asked ·

Transmission has a glowing rim when layering two objects with transmission

I am experiencing an issue with my eye setup. As you can see in the image below, I have a glowing rim around the edge of the eyeball in the transmission pass. The caruncle geometry overlaps the eye, and both have transmission enabled.


Both the caruncle and sclera materials are using the aiStandardSurface. Both have Opaque set to Off, and both are using Transmission. The head, caruncle, and eyes all are part of the same SSS Set Name as well.

Here is the shader setup for both caruncle and eye:

As you can see, both are very similar, the only difference being that the caruncle has a bit of control over the transmission depth. Disabling this and matching the eye still gets the same results.

Any ideas how I can remove this weird rim light on the transmission pass? It appears only when the eye is in shadow, as the other eye, in light, doesn't have the rim visible, as seen here:


Lastly, my render has little red dots all throughout, they don't appear in any AOV, only in the beauty pass. Clamping values doesn't remove them. Any ideas there?


I am running the latest Arnold release, 3.3.0.2 - f5753062, in Maya 2018.


Thanks.

shadersskin
eyebeautyr.png (80.5 KiB)
eyebeauty.png (85.2 KiB)
eyetrans.png (36.1 KiB)
sclerashader.png (34.6 KiB)
caruncleshader.png (34.4 KiB)
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Lee Griggs avatar image
Lee Griggs answered ·

Are you using SSS Set Name?

Which SSS type are you using?

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I am using SSS Set Names, all objects are set to "1".

I am also using randomwalk_v2 for all objects.

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Lee Griggs avatar image
Lee Griggs answered ·

Do you have a simple scene that reproduces the issue with red pixels?

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I tried rendering a simple scene, with just the head and a single area light. The red dots in the original post weren't the only color, so in this render some of them are now blue.

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spot.png (59.4 KiB)
spot.png (75.6 KiB)
lightsetting.png (41.2 KiB)

The light intensity is very bright. Does lowering the intensity affect the pixels?

I would leave Intensity at 1 and just use Exposure.

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I did that with the HDRI dome I was using, it was a default value of 1, and then I just adjusted the exposure values, which was used for the original render that shows the red dots.

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Lee Griggs avatar image
Lee Griggs answered ·

Where should I see the odd pixels?


1578497909433.png (609.6 KiB)
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Closeup render.

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untitled-1.jpg (184.4 KiB)

It is random each time the lighting/camera angle changes. There is never any consistency as to where they appear. I added a camera in the scene I sent you, using the HDRI that is included in the scene should show similar results to the RenderError.png included in the .zip

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