banding issues on render passes with Octane 2020

[mrbrown]

Hi there,
having some gradient banding issues in the render passes file.
The scene is simple, a black cylinder in a black scene.
The live viewer and the beauty render show the cylinder correctly, with smooth reflection.
the reflection layer in the render passes has very strong banding.

The render buffer is set to "tonemapped", camera images is set to linear and so is the render passes image color profile and tonemap type in the render settings.

Please help.
Thank you.

[mrbrown]

So I did some additional tests and here is a super simple test scene.
It's a black sphere in a black environment with a 3 light set up.

I rendered a render pass with diffuse, reflections and material ID psd 16bits and a beauty png at 16bits.
I tried many combinations and setup, different files format but can't manage to get a render pass at 16 bits without gradient banding.

I also tried exr 32bits.
That works, but then the problem is that I can't edit the image in Photoshop (many photoshop tools don't work at 32 bits) so then I try to convert to 16 bits the image doesn't look right anymore.

I would really appreciate if anybody can help me figure this out.

You can check the scene here.
https://app.box.com/s/2xchgvwayeihptz6s10sg34dpq04o78i

Thank you.

[bepeg4d]

Hi,
the issue should be already fixed in 2020.1.3-R2, please, go to c4d menu Script or Extensions/Console, (Shift+F10), and share a complete screenshot of the panel, thanks.

ciao Beppe

[mrbrown]

Ciao Beppe,

Thank you for looking into this.
I think the issue is happening also with the latest release 2020.1.3 -R2

Here is the console screenshot.

Grazie!

[bepeg4d]

Hi Marco,
I have checked your scene with 2020.1.3-R2, please avoid to use the C4D Saving options, when you enable Octane Multi pass, and use its saving options instead:


The banding option is visible only in Picture Viewer, if you open the saved PSD file in PhotoShop, everything is correct.

Here is the modified scene file:

black_ball_test.c4d.zip

(208.63 KiB) Downloaded 167 times

ciao Beppe

[mrbrown]

Hi Beppe,

Thank you but I need the output to be in linear color profile.

I've done some more tests and I came to the conclusion that there are discrepancies between the Octane 4 and the Octane 2020 plug-in.

Please take a look at the scene attached. It is set up for Linear workflow.

- If you open the scene with Cinema and Octane 4 (4.07-R7) and save a render pass you get a PSD layered file at 16 bits with no banding and the diffuse and reflections can be added in Linear Dodge (add) correctly and the result is exactly the same as the beauty.
- If you open the same exact file with cinema and Octane 2020 (2020.1.3-R2) and save the render pass it does not work the same. the PSD file has very strong banding and it is basically unusable.

Can you please explain why is this happening and what should be done to achieve the correct result with the latest plug in?

Please see attached scene and psd comparison.
Thank you.
Marco

[aoktar]

It's not giving the problem if you copy/paste all things from this scene to new one. There should be some wrong parameters come from V4.

[mrbrown]

Hi Aoktar,
I tried to copy all the elements in a new scene and re -render but it does not look like is solving the issue.
Would you mind uploading the scene that is working for you so I can test here?
Thank you.
Marco

[aoktar]

New scene with latest 2020?

[mrbrown]

yes, 2020.1.3-R2