Great work on this crazy part, Philo. And thanks for showing how you did it. I made the under studs in 95188 in a similar way but your use of ytruder was much cleverer than what I did (used intersector and hand editing). If I'd seen this first I could have saved some time and I might get a chance to use it if I add more underdetails.
To make things work in POVray you could extend the quad section only down to 8LDU (or whatever) above the ground plane and use primitives to make the final 8LDU. You'll end up with a weird intersection in POVray but I think the result would look better in POVray than just having polygons since the join will usually be in shadow.
eg. http://www.ldraw.org/cgi-bin/ptdetail.cgi?s=95188
Tim
To make things work in POVray you could extend the quad section only down to 8LDU (or whatever) above the ground plane and use primitives to make the final 8LDU. You'll end up with a weird intersection in POVray but I think the result would look better in POVray than just having polygons since the join will usually be in shadow.
eg. http://www.ldraw.org/cgi-bin/ptdetail.cgi?s=95188
Tim