Multichannel in AE - lightpasses were cropped by alpha

[BeneZ]

Hello,

Is it possible to save a multiEXR without alpha?
I have an object with transparency and want to get it with light passes in front of the background color.

It's impossible in AfterEffects with EXtractoR. It's always multiplied by alpha and no operation can revert it.

I would like to avoid rendering everything in single passes.
Any other suggestions?

This topic took me hours today with testings.
Thanks

[hermit.crab]

You can ignore the alpha of the .exr in AfterEffects. Select the .exr (in the Project panel), then go to File>Interpret footage>Main>Alpha>Ignore; afterward import the image in the composition.

[BeneZ]

Thanks, I know, I do it always for the RGB, but it’s not working for the light passes.
I opened them meanwhile in Nuke and found out;
The light pass has no data of the background.
Even when I fill the Alpha with white there is no picture.

I guess, that‘s because it is not „seeing“ the empty background.
(There is nothing but an environment color)

I was thinking to get different light situations, which I can blend over, but it’s not working for transparent parts then.
Is there a way to render the environment also into the lightpass?

[^Lele^]

Sounds like auto-cropping.
Could you send me/support the misbehaving EXR?

[hermit.crab]

BeneZ In that case, it is better to premultiply the alpha and compose the light selects with the background (solid; or a VRayBackground could be rendered). You can get the environment GI effect in a VRayLightSelect through the Light path expression mode. It is available as a preset (Presets>Misc).

[BeneZ]

Thank you all, I think it is just the behavior of light passes,
when the environment is just a color.
(maybe you implement in future an option to render this including environment color).
I will try to solve it by using a color plane or as duggested by compositing.