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Clay Hammons avatar image
Clay Hammons asked ·

Bump showing in viewport but not in Arnold render

I have a grayscale bump texture going into a bump node and then into the Normal slot of the Arnold Standard Surface shader. For some reason it will only show in the viewport and not when I render. I have tried changing between srgb and raw for the texture, I have tried extreme values for the bump amount. The bump node is set to Bump. I have also tried both Maya and Arnold’s 2d bump nodes, Im at a loss. This is for a human face on a character and for some reason if I check the Thin Geometry box it will render the bump but it greatly darkens the entire face. I also tried using a normal map setting the bump node to tangent space normals as well as enabling export tangents on the geometry but it had the same result. Any ideas? :/

normal map
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Zeno Pelgrims avatar image
Zeno Pelgrims answered ·

I had a look at your file but nothing seems wrong. It is a result of the SSS model not taking bump into account. For assets like this it is totally worth to displace your mesh instead. Arnold does a great job of converting any texture detail for which the mesh does not have a resolution to support it into bump, so you don't even have to worry about it yourself.

If you look at the spec aov, you can tell it's there:

In your sss aov however, it isn't:


render-seems-ok.png (435.7 KiB)
render-spec.png (157.6 KiB)
render-sss.png (251.7 KiB)
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Clay Hammons avatar image
Clay Hammons answered ·

Here is an image of my graph:


bumpissuegraph.png (64.6 KiB)
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Lee Griggs avatar image
Lee Griggs answered ·

Yes, try reducing SSS Weight below 1 to see if that helps.

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Clay Hammons avatar image
Clay Hammons answered ·

Thank you for your help Lee, my graph appears to be correct. I am placing a link to a stripped down version of my project (Maya 2018.4). Let me know if you would prefer any other information. I am somewhat new to Arnold moving from Mental Ray so I am probably missing something simple. Thanks in advance!

https://drive.google.com/open?id=15h5ROS7Efqe--zm37z6Om17Pc38wIwMA

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Lee Griggs avatar image
Lee Griggs answered ·

Your shader connections look like this right?

Can you upload the texture/shader or/and add screengrabs?

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