Premultiplied alpha bug

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J.C
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There is serious bug in Blender plugin causing white edge on an image with transparency. Standalone render fine. In both cases "Premultiplied alpha" is disabled.
alpha bug.png
I attach both versions for comparison.

Edit:
I've found the reason of such behaviour. The Blender's Color management gamma was set to .04545 and Display device was set to sRGB.
Setting back Display device to None and gamma 1 brought back the correct alpha on renders.
Attachments
alpha bug.blend
(13.07 MiB) Downloaded 167 times
alpha_bug.orbx
(13.29 MiB) Downloaded 164 times
Last edited by J.C on Mon Nov 18, 2019 9:00 pm, edited 2 times in total.
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aufwind
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Hi JC,

it should work if you enable "premultiplied alpha" and keep the "disabled partial alpha" unchecked.
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J.C
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aufwind wrote:Hi JC,

it should work if you enable "premultiplied alpha" and keep the "disabled partial alpha" unchecked.
I've tried all scenarios. Same result. The file was opened in Photoshop where it displayed like this. What's strange that file opened in in After Effect behaved properly.
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J.C
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This is how files look like when opened in Photoshop:
alpha_bug.png
CPU – i9 13900KF, 128GB RAM, GPU – RTX 4090
System – Windows 11
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J.C
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This is how After Effects interprets the Blender renders:
alpha_bug ae.png
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J.C
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And this is how it looks like in After effects with Standalone renders:
alpha_standalone ae.png
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aufwind
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I don't know why you get these strange results. I've even tried you're Blend File.
Here my results rendered in Blender Plug-In with the Settings mentioned in my post.
Suzanne with and without DOF. Background inserted in Photoshop.
Suzanne.jpg
Suzanne DOF.jpg
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J.C
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aufwind wrote:I don't know why you get these strange results. I've even tried you're Blend File.
Here my results rendered in Blender Plug-In with the Settings mentioned in my post.
Suzanne with and without DOF. Background inserted in Photoshop.
Have you tried different background like mine on the example? On some backgrounds it is more visible than on others.
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J.C
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aufwind wrote:I don't know why you get these strange results. I've even tried you're Blend File.
Here my results rendered in Blender Plug-In with the Settings mentioned in my post.
Suzanne with and without DOF. Background inserted in Photoshop.
[/attachment]

Another example:
standalone vs plugin pm.png
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aufwind
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For you to try out just the Render Layer with alpha channel Export and a Version with a different background.
I'm still on Octane Blender Version 3.07. So maybe it is a Problem with newer Versions or just some setting problems in Photoshop...
Suzanne DOF.png
Suzanne DOF.jpg
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