Ouch its late..
I have just spent the evening getting papervision objects to sort correctly depending on the distance from screen center. This is something that papervision will do automagically by default but only if all objects are on one ‘layer’ and in these case strange clipping artifacts are created :-(…
The blue lines above represent distance checks to the building edges, the 3d objects are then sorted in reverse order, so the smallest distance away has the highest Z value. I might post a bit more insight tomorrow - but for now, i need to sleeeep!
