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Premultiplied alpha bug
Posted: Fri Nov 15, 2019 11:00 pm
by J.C
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.
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.
Re: Premultiplied alpha bug
Posted: Sat Nov 16, 2019 9:53 am
by aufwind
Hi JC,
it should work if you enable "premultiplied alpha" and keep the "disabled partial alpha" unchecked.
Re: Premultiplied alpha bug
Posted: Sun Nov 17, 2019 5:06 pm
by J.C
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.
Re: Premultiplied alpha bug
Posted: Mon Nov 18, 2019 11:09 am
by J.C
This is how files look like when opened in Photoshop:
Re: Premultiplied alpha bug
Posted: Mon Nov 18, 2019 11:24 am
by J.C
This is how After Effects interprets the Blender renders:
Re: Premultiplied alpha bug
Posted: Mon Nov 18, 2019 11:32 am
by J.C
And this is how it looks like in After effects with Standalone renders:
Re: Premultiplied alpha bug
Posted: Mon Nov 18, 2019 3:49 pm
by aufwind
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.
Re: Premultiplied alpha bug
Posted: Mon Nov 18, 2019 6:03 pm
by J.C
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.
Re: Premultiplied alpha bug
Posted: Mon Nov 18, 2019 6:38 pm
by J.C
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:
Re: Premultiplied alpha bug
Posted: Mon Nov 18, 2019 6:58 pm
by aufwind
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...