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Q: Quixel and Arnold 5 settings?

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RobWu null
Hi All,

I know it's early days, but with the new Arnold 5 and Arnold Standard shader the current export presets aren't correct.
Is there someone out there who figured out what to use now, as the new shader leans more towards the PBR workflow.

cheers!

rob

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  • Billy Lundevall
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    Billy Lundevall polycounter lvl 7
    Hello Rob! I am perfectly aware of this, if you start out with the Disney PBR preset and then set your roughness and normal maps in Arnold to RAW, even if originally in SRGB, before TX conversion and set the roughness map to "Alpha Is Luminance" under it's color options you should be good to go :).

    The color space of TX converted maps is a little bit confusing so far, I really don't know why this is the case, but that is what looks the closest without further tweaks. 
  • RobWu
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    RobWu null
    Hi Billy,

    Thanks for the answer.
    I have to retry the Disney PBR, as it wasn't getting anywhere close to 3DO. It might be the .tx conversion in Arnold5 that is confusing.

    I also tested the PBR GGX setup, and that was giving me the same result as the Disney PBR: The specular roughness is way off and too glossy. In the end I had to set all textures to sRGB, turn OFF 'Alpha is Luminance' for spec. gloss, and have the gamma for this set to .454 to get 90% towards 3DO.
    Have to figure out what the automatic .tx conversion is doing on sRGB files, as it looks as gamma is going odd somewhere. Also .tx convertion of sRGB to linear, renders not as expected.
    I like the new shader setup and gamma in Arnold5, but there are some questions for now ;)

    rob
  • Billy Lundevall
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    Billy Lundevall polycounter lvl 7
    My testing hasn't been too extensive so far, and only done on my own Megascan compiles. I get the roughness fairly close if I load the RAW files here and if they are off I simply tweak a little with the Alpha Offset of the map in Maya, this isn't by much though.

    But then again, I haven't done any Suite to Arnold 5 testing yet. And the problem with the roughness always being too shiny was there in Arnold 4 too. That part is simply 3DO and Arnold not reading the maps the same way, this needs to be compensated for in a future preset. For now, the Alpha Offset works as an easy fix :).

  • Paolo_G
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    Paolo_G null
    Hi
    I am also very curious about why Arnold can not seem to read correctly the roughness map. 
    Is the alpha offset tweak you are doing always a fixed value? Or it must be calibrated per asset? It would be amazing to have a fixed way to obtain a similar result to 3DO.

    Cheers
    Paolo
  • RobWu
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    RobWu null
    Hi Paolo,

    As far as I can tell, the tweak for specular roughness hovers between .25-.35 for the alpha offset. Roughly half of the inverse gamma.
    It's something 3DO I guess, as Painter doesn't seem to have this issue when testing the new Arnold 5. You just set all grayscale textures to RAW and 'alpha is luminance' and it matches Painter almost 100% when using the pbr-metal-rough shader in Painter.

    Hope it helps,

    rob
  • kikou
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    kikou null
    Hi everyone,

    I'm with the Arnold team. We want to help. Could you send me a model, textures and a reference so we could have a look? PM me.

    Cheers,
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