"Is this faster then using True ambience.?"

shrug  I haven't got a clue, Vile.   I haven't done any investigations into the comparative uses of TA vs. hdri.   This was purely an exercise in self-created hdri applications.  There are so many things about Bryce I still don't know after all these years playing in my fave program.  My to-do list is already a mile long, and it grows daily.  

RosemaryR
---------------------------
"This...this is magnificent!"
"Oh, yeah. Ooooo. Aaaaah. That's how it starts.
Then, later, there's ...running. And....screaming."