b3d_rad - a radiosity processing/lightmapping solution for Blitz3D

So how exactly does one take a level into FRad for lightmapping? FRad doesn't seem to have any documentation and it isn't obvious (eg. how do you place lights?)

EDIT: Dumb question. I thought b3d_rad was only for importing lightmapped scenes from FRad. I didn't notice there is also functionality to save .oct files from Blitz.