C4D Picture Viewer PNG w/ Alpha

[-rb-]

Hi,

Just working through this - if I render through C4D standard renderer using Octane with Alpha enabled, and save to a PNG, I get a blank PNG. If I render using the Live Viewer, and save as a PNG from the live viewer, I get geometries rendered with a transparent alpha (works). Also, if I enable any of the multipass channels in C4D (reflection etc.), they are all black also. What multipass channels does Octane support - and how can I render using C4D standard renderer window and get a PNG with an alpha?

Thanks!

- Rich