as the title says - in photo merging you want to render your scheme in the 3d context to get reflections and shadows but don’t want the context to be visible so you can drop the final render of your scheme and alpha mask it in to your image and not have to paint out overlapping objects.
This would be a super useful and essential function for compositing to photos to make any object in the scene render but not be visible in the final image so you can get the shadows and reflections it generates but not see it and it not effect the alpha channel so it doesn’t compromise compositing as well.
this would be i believe a step up in D5’s usability for the arch viz industry… otherwise it just sits as an interactive render only at present for prebuild virtual sets only…