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Compositing passes in Photoshop

PostPosted: Sat Aug 11, 2018 10:07 am
by AndreasResch
Hey.

Can anybody give me an advice about how to combine beauty passes in Photoshop correctly? When using "Linear Dodge (Add)" the result comes out way too bright. When using "Screen" as some suggested, the result still looks different from the Combined pass. I used both Diffuse passes, both Refelction passes and the Refraction pass on top of each other.

Here'a are the two tests.

Octane_Issue_17.jpg


Octane_Issue_18.jpg


Any help is appreciated.

Cheers,
Andreas

Re: Compositing passes in Photoshop

PostPosted: Mon Aug 13, 2018 6:52 pm
by J.C
Have you tried Photoshop extension from the official downloads page?
viewtopic.php?f=24&t=68091

Re: Compositing passes in Photoshop

PostPosted: Mon Aug 13, 2018 6:59 pm
by J.C

Re: Compositing passes in Photoshop

PostPosted: Tue Aug 14, 2018 7:06 am
by AndreasResch
Hello, JC.

Thanks for the feedback. I tried the extension but it requires a format called OCPRJ that I don't have and don't want to use either. I'm fine with any file format that Blender can export.

As for the tutorials. I've watched them before but it doesn't work like that with Blender. As you can see above, the "Linear Dodge (Add)" belnding mode results in a much too bright image. The tutorials use PSD as export image format which is not an option in Blender, although I don't think that should make a difference. Maybe it's about the way images are exported in Ciname4D compared to Blender.

So - the question remains.

Cheers,
Andreas

Re: Compositing passes in Photoshop

PostPosted: Tue Aug 14, 2018 7:30 am
by J.C
I will check this out later this week. Maybe multi layer exr 32bit will be better as a file format?

Re: Compositing passes in Photoshop

PostPosted: Tue Aug 14, 2018 7:33 am
by AndreasResch
Hey, JC.

I've also tried Multilayer EXR without success. But maybe you're more lucky. The best case would be if I could use it with 16-Bit though. 32-Bit is an unnecessary extra step for my workflow.

Cheers,
Andreas

Re: Compositing passes in Photoshop

PostPosted: Tue Aug 14, 2018 3:56 pm
by AndreasResch
Hey.

I've experimented for a while now and there are 3 ways to get the compositing done in Photoshop. They all use Linear Dodge (Add) as blending mode.

1) Export straight OpenEXR and correct gamma in Photoshop (32 bit)
If you export the passes as OpenEXR directly from Blender, you need to adjust each layer/pass by a gamma of 0,4545 (1/2.2). This looks something like this ...
Octane_Issue_20.jpg
Octane_Issue_20.jpg (51.73 KiB) Viewed 5172 times


2) Export gamma corrected OpenEXR from Blender (32 bit)
If you place a Gamma node set to 2.2 between each of the passes and the Output node, you don't need to compensate for it in Photoshop. That looks something like this ...
Octane_Issue_19.jpg


3) Export TIFF and work in a linearized color space within Photoshop (16 bit)
If you prefer to wotk in 16 bit you need to convert your imported passes to a linearized color space with a gamma of 1. Of course you have to save it in this color space as well if you want to preserve the layers. I've uploaded the ICC file in case you should need it.
http://www.andreasresch.at/upload/Linear%20sRGB.icc

I will see which one of this methods I will use - probably 2 or 3.

Cheerio,
Andreas

Re: Compositing passes in Photoshop

PostPosted: Mon Aug 20, 2018 8:46 pm
by J.C
Hi Andreas,

Can you provide your .blend file and photoshop to compare? I can't get the same results when doing passes too.

Re: Compositing passes in Photoshop

PostPosted: Tue Aug 21, 2018 5:53 am
by AndreasResch
Hey, JC.

Which workflow do you prefer. The 16-bit one or one of the 32-bit versions?

Cheerio,
Andreas

Re: Compositing passes in Photoshop

PostPosted: Tue Aug 21, 2018 8:14 am
by J.C
Hi Andreas,

I prefer any workflow that works :)
The closest results I get is method 2 but the indirect reflection pass quite subtle in this mode.

passes.png


What is your camera imager settings?