corona object buffer - animation

[daveclive]

can't seem to get the object buffer layer 'Right hanging bracket' rendered out as a transparent png.

I select 'straight alpha' and use png format but once rendered the multipass layer/ object buffer layer has a black background baked in.

1st screenshot shows the c4d setup.
2nd screenshot shows the rendered multipass layer witht he black background baked in.
3rd screenshot shows the rendered beauty layer with the transparency correctly baked in.

I'm rendered a png image sequence for animation
C4d R20
Corona Version: 5.0 daily Oct 15 2019

any idea why can't get the buffer pass with transparency enabled?

[daveclive]

I realise screenshot 3 looks like it has a black background baked in from the attachment, however this render has the transparency baked in correctly.
Have reattached a new screenshot which shows transparency grid

[daveclive]

My aim is to be able to isoltae the tools and the right hanging bracket so I can use overlays/ effect in post-production.
renered will be thousands of frames.

Originally I was doing it via render select. Dropping in the object individually and saving a new scene then rendering that sequence with it's own file name.
Surely there's got to be a better way using the object buffer?

[daveclive]

Any solutions please?!

[houska]

I tried this for a while and then I realized - why would you want alpha there? It's a mask channel! The mask is defined by white pixels and the rest is black. I think this is by design