Mixing channels in EXtractoR (AE 23.6.9)

[chloé_3305]

Hello there,
When I import exr file into After, and apply EXtractoR, with some exr it does not show correctly the channels, mixing another channel into another.

If I read the exr with MRV2, it shows correctly.
Anybody have a clue to solve this bug?

[john_7484]

Hello Chloe,

It seems the issue might be due to how EXtractoR is interpreting your EXR file's channels. Try re-exporting the EXR file with standard settings, or check if the channels are correctly labeled. If the problem persists, using MRV2 as you've mentioned might be the best workaround.

Hope this helps!

[chloé_3305]

The same Exr shows correctly into Nuke, Natron and Blender compositing and also Mrv2. It only bugs into After.

[chloé_3305]

Hello,

It seems I have a special case.
The first image is empty in all channels, and it seems EXtractoR does not like that.
I suppose that it cannot create the cache, if first image is empty, that a sort of bug? @fnordware

[fnordware]

Is it a single EXR or part of a sequence? Can you post it somewhere so I can take a look?

[chloé_3305]

It's  a sequence, I've sent a private message with a link.
Thanks for your help.

[fnordware · Accepted solution]

Thank you, I got it.

The problem is that not all the EXR files in your sequence have the same channels. If you import each frame individually you'll find that EXtractoR works as expected, but it'll show different channels in the list. You can also see this by clicking different frames in the project window and checking the readout indicating the number of channels.

The reason this causes a problem has to do with the AE API. While I'm retrieving channels by their names, the API internally uses an index number. For a sequence it uses the first frame to index the channels, but if a later frame has different channels the index will get misaligned and you'll get the wrong one.

Hopefully this happened because you made changes to your channels and didn't re-render the ealier frames, not some Blender behavior.

[chloé_3305]

Thank you fnordware,

You're right, it certainly the case. We've not re-render the first frames, or Blender did not overwrite the first frames, after modifying the channels, and that why it messes the EXtractoR preview if the channels are misaligned. Meanwhile, we have re-rendered all the sequence and it works perfectly.