Gamma override feature is not working with Max 2018 and Arnold

[ddankhazi]

Hi there,

At the bitmap import window the gamma override feature is not working.
It shows the preview correctly, but in the rendered image there are no difference between the two (gamma 1.0 and 2.2).
This is a huge problem.
For example: I can't use my painted Roughness maps directly. I have to double gamma correct all non color related texture manually!!!!!

A fast fix for this would be great. I'm not sure this is a Max or an Arnold bug.
I'll do more tests with different render engines.

Thank you, D

[ads_lecoufm]

Hello there,

I have a few questions a we've been unable to reproduce on our end.  I'd like to start with my #1 Arnold question: are you using version 712 3ds Max 2018 ships with or did you upgrade to Arnold 812? (Available for download here: https://www.solidangle.com/arnold/download/)

Could you also share some images and details on your setup?  What file type are you using, materials, etc?  Thank you for the information, have a good day!

Marianne

[ads_lecoufm]

Hello,

My apologies, we actually have a way to reproduce - it is quite obvious with gamma 5.  The only workaround as you pointed out right now is to use color correction meanwhile.  It's been logged and will be addressed soon, thank you!

Marianne

[masterzap]

Gamma 5 isnt legal, we only support 1.0 or 2.2 - see the warninhs

[ads_lecoufm]

Oh yeah, I remember the warnings now...

[ddankhazi]

Hi Marianne and Zap,

I'm using Arnold 1.0.812.

The shader is a Standard Surface.

I had to double gamma correct (before the import) the roughness texture (because of the gamma override bug) to get exact match with Substance Painter.

The results (left to right):

- Rendered image using Gamma override: 1.0
- Rendered image using Gamma override: 2.2 As you can see no difference 😞

- Original painting in Substance Painter



By the way the native Substance Painter texture connections:

Cheers, D

[masterzap]

I would need a repro case using the legal values (1.0 or 2.2), because I cannot repro this. It is working fine for me, if I use the legal values.

/Z

[ddankhazi]

Hi Zap,

I never used illegal values, as you can see my original post (gamma 1.0 and 2.2).
I did some more test. This is a problem only with Arnold.
With every other render engine the override feature works as it should!
By the way this problem is existing in 3ds Max 2017 with the Arnold beta as well. 

Here is my test scene:
https://dl.dropboxusercontent.com/u/83350004/Arnold/3dsMax_arnold_test.zip
The second texture is the manually modified image.

Thank you,
Denes

[ddankhazi]

Hi Zap,

I was able to render the correct image.

Here is the trick:

- If I switch to ART Renderer and try to render (the render starts, but of course I get an error message, becasue of the Arnold Standard Surface material)

- Stop the rendering process

- Switch back to Arnold

- Now the render is correct

Please fix this. Thank you.
Denes

[masterzap · Accepted solution]

Ok, you scene helped. The bug is caused by having "Use existing .tx" turned on.

Turn that off, and it works.

/Z

[ddankhazi]

Oh. I see.
And now I understand why the ART render switch solved my problem. If I switch back and forth the render settings goes back to default, and with that the use existing tx option as well.
Thank you, this is good news.
Cheers, Denes

[masterzap]

This is now fixed in the new build. It was a simple typo in the code that made the "Use existing .tx" switch to break the gamma options (it should have nothing to do with it); very good you found this!!

/Z