I agree...Terragen (free) is wonderful for doing your own backdrops that can be adapted into the DAZ Cyclorama setting.  I believe they can also be worked up into the RDNA Infinity Cove.  All you need to do is take the picture you generated, cut it to fit the template or another background/floor from either of the other two, and apply it through the materials room.  I've had pretty good success doing this in the past.