[Regression] Stingray shaders broken in Maya LT 2020

[sir.seko]

I have a somewhat complex stingray shader that I've put together in Maya LT 2019 to be able to gauge how textured assets are going to look in Unreal Engine 4. In 2020 however I'm getting some weird banding/reflection(?) issues, see the attached screenshot. Left is 2019, right is 2020, same exact file and shader. On the second screenshot you can see the default stingray shader exhibiting the same banding issue so it's not even my shader that's messing things up.

[Anonymous]

I had the same problem. It's due to the ibl_brdf_lut.dds cubemap file. For a quick fix you can swap the ibl_brdf_lut.dds (located here C:\Program Files\Autodesk\Maya2020\presets\ShaderFX\Images\PBS) with the specular_cube.dds (located here C:\Program Files\Autodesk\Maya2020\presets\ShaderFX\Images\PBS\midday). Just make a copy of the specular_cube.dds and rename it to ibl_brdf_lut.dds and replace the original. 

If you want to create your own cubemaps you can follow this post

[sir.seko]

Thanks so much, it worked!

[adam.lacko]

You're a livesaver, thank you.

[Anonymous]

Hey! I had the same problem here using Maya 2020.2. I follow the same procedure but it was appearing black reflections to me. So, instead copy the file 'specular_cube.dds, I copied diffuse_cube.dds and renamed. It's looking good to me now. Thanks for helping us!

[Anonymous]

DOES NOT WORK HERE!
in Maya 2020 LT that's what I get doing your tip.

[Anonymous]

The same with Maya and Maya Indie 2020.2, the problem persists...

[gallowj3MBSK · Accepted solution]

Here is a real fix.

It appears that the brdf lut texture that ships with Maya 2020 is corrupt.  This lut describes brdf information over the hemisphere of curved surface, it's a map that describes how to look up into the cubemaps for lighting values. You get the weird banding because corrupted lut has a bunch of noise in it.  If you copy and replace it with another .dds file that isn't corrupt it's going to probably look better (but is actually still very wrong).

You need to replace the corrupt lut file with a correct lut file, like this one from IBLbaker:

https://github.com/derkreature/IBLBaker/blob/master/maya/brdf.dds

Download that into the same directory as the one that ships with maya. You can replace the broken one with it, or you can just load it directly into the correct slot for the brdf lut on the stingray pbs material nodes (usually file3)

[Anonymous]

Thank you for posting this. Yes. My fix is more of a hack so this is the correct solution. Not sure how to mark this as the correct solution. I think that’s up to the original poster. 

[Anonymous]

 gallowj3MBSK

 Thank you so much for supplying the fix, I was about to tear my hair out lol. I needed my project to be fixed for my class assignment and this helped me thank you!