Thanks bagginsbill - using poser.Scene().CurrentCamera().WorldDisplacement() as you mentioned in the other thread ( http://www.renderosity.com/mod/forumpro/?thread_id=2886725&page_number=2#msg4184517 ) seems to be exactly what I was after, and much simpler than my Heath-Robinson-esque coding attempts!

But also I'm really trying to understand the 'why' and 'how' of these darn orbiting cameras. Every time I think I understand them they seem to go and do something bizarre. E.g. I had just convinced myself (once again) that the Main/Aux cameras always rotate about the world origin (as per the User Manual, and aRtBee's observations here http://www.book.artbeeweb.nl/?p=3069 under "Camera Type"). But then I loaded a couple of buildings off to one side of the origin - they were the only things in the scene. With DollyX/Y/Z and OrbitX/Y/Z all set to zero the Main camera view was as expected. But when I spun the OrbitY the main camera seemed to rotate about what I guess was the centre of the combined buildings I had in the scene.

I'm sure I recall reading somewhere that the Main/Aux cameras rotate about the centre of the scene (which is usually at or near the world origin) - but can I find the reference? of course I can't...

---

The 3Dcheapskate* occasionally posts sensible stuff. Usually by accident. And it usually uses Poser 11, with units set to inches. Except when it's using Poser 6 or PP2014, or when its units are set to PNU or something else.
*soon only to be available in two flavours -  DAZ and Renderosity