It started innocently enough, with my new Sigma 15mm diagonal fisheye lens and the parking lot of my local mall. Looking at the result, I thought it would fun to make it into a mini-world. About halfway through the process I decided to try "polar to rectangular" instead of "rectangular to polar". This is what I got, completely unexpectedly. I used Topaz Adjust also. (For those who may not know, a half-pipe is a structure used for skateboarding and snowboarding.)