Hi Acie,
I have read about some scripts that will auto create separate sculpt maps for each item and upload them. However I have not heard of anything for what you are trying to do.
So unless there is something new out there I have not heard of, combining more than one
object into a single sculpt map would be prohibitively difficult. That is, that I am sure it is possible but there is no reason to do it that way.
You need to be pretty careful with your object in order to get a good sculpt result as the sculpt map is baked from information from the UV map. When you add a whole separate
object to it and try to jam them together it just makes it a big mess. I would think that what you are seeing is the result of blank or black areas on your uv map caused by distortions
of jamming your uv maps together. If you cannot get the level of complexity you wish with one object you can simply make a separate object that will have its own sculpt map.
then you can assemble the parts in SL.
In addition all exporters have their own rules for any kind of successful use and I am certain that the ac3d exporter does not allow for multiple uv mesh integration within its export routines.
It would be sort of like sewing your jacket to your pants before going outside.
