Incorrect Rendering of Exr

[MJx]

The exr file does not render correctly in the software. Have a look at what affinity does to the exr as compared to what  blender rendered and what was uploaded online to check

Edited January 6 by MJx

[carl123]

Can you upload that exr file to the forum so it can be checked in the beta and so the devs have something to test with?

[MJx]

sure here is the exr file :

0001.exr

[carl123]

The thread below shows 2 different things you can try with this image

One uses the 32 bit preview panel

The other users a Procedural Texture equation (Affinity Photo only)

Both appear to give similar result to the 1st of 3 images you posted

 

[James Ritson]

Hey @MJx, the solution here could be more involved than just adding a gamma transform. What transforms are being used in Blender, e.g. AgX, Filmic? (And are you applying any looks?)

These transforms aren't written to the linear EXR file (which is intentional), so you won't see the same result. You'll want to recreate these in Photo, typically using OCIO, but there are macros available for Filmic and AgX that replicate these transforms without the OCIO dependency.

Bear in mind that changing the Exposure and Gamma sliders in Blender also won't affect the pixel values that are written to EXR, so you'll want to adjust these as well. You can use an Exposure adjustment for exposure and a Levels adjustment for gamma.

Also, if you want to associate the alpha on import (rather than it being imported unassociated as a separate layer), have a look in the Settings menu under Colour. There's an option called "Associate OpenEXR alpha channels", plus further alpha manipulation options. This will give you the transparency you see in Blender's viewport straight away.

Hope that helps!

[MJx]

 

4 hours ago, James Ritson said:

What transforms are being used in Blender, e.g. AgX, Filmic? (And are you applying any looks?)

I am using the attached colour management setting in Blender
but this should not matter , the image is RGB actually , there is no alpha channel . The blender is also showing a buggy output ( showing squares instead of black. But the online openexr veiwer and Da Vinci Resolve are displaying the produced output correctly.

 

4 hours ago, James Ritson said:

Bear in mind that changing the Exposure and Gamma sliders in Blender also won't affect the pixel values that are written to EXR, so you'll want to adjust these as well. You can use an Exposure adjustment for exposure and a Levels adjustment for gamma.

I am not changing that as you can see

 

4 hours ago, James Ritson said:

Also, if you want to associate the alpha on import (rather than it being imported unassociated as a separate layer), have a look in the Settings menu under Colour. There's an option called "Associate OpenEXR alpha channels", plus further alpha manipulation options. This will give you the transparency you see in Blender's viewport straight away.

There is no alpha in the image . I just instructed Blender to write the RGB (the bug in Blender preview as well)

[James Ritson]

19 hours ago, MJx said:

I am using the attached colour management setting in Blender
but this should not matter , the image is RGB actually , there is no alpha channel . The blender is also showing a buggy output ( showing squares instead of black. But the online openexr veiwer and Da Vinci Resolve are displaying the produced output correctly.

I'm not sure that's buggy, you probably have Transparent checked under the Film settings. The squares are alpha checkerboarding. The EXR will be saved with unassociated alpha, which will come into Affinity Photo as a separate pixel layer called "A".

If you're referring to the colour management, this does matter: what you're seeing in Blender is not what you will see when just opening the linear EXR in other software. It might be close with Linear Rec.709 primaries, but not exact. You would likely want to use OCIO colour management to ensure the EXR colour space is converted correctly when brought into Photo (or other software), and that the correct view transform is being applied.