How to create a AR Project and use it as Foreground in VIZ Artist

Hello all,

I couldnt find something fitting my purpose but maybe I just wasnt searching at the right place.

Im fairly new and have little to none knowledge in UE…
I want to have a AR Object in my UE Project and send it with alpha channel to Viz Artist to then use the UE Output in the foreground of a virtual surrounding. How can I get a correct “object-only” output or said differently: how can I make the world invisible/dissappear. I activated “allow through tonemapping” for the alpha channel and tried just deleting everything in the world except for the object/geometry and a light source. How can I know get rid of the “empty” black environment?

Thanks appreciate help or a link to documentation / tutorial!