The transporter pads were especially fun to model / texture.I started off with the best reference material I could find, which is a screen cap from the third season episode Elaan of Troyius
. In this episode, we get a rare up-close glimpse of one of the transporter pads (and a pair of Elasian feet).
I did some research and discovered that the transporter pads were actually made from Fresnel lenses of 10,000-kilowatt set lights. I was able to then google up some images of actual Fresnel lenses and found a diagram of their shape. I then modeled a high-poly version in 3ds Max and made a simple normal map to apply to my low-poly model of the pad.
I then ported the texture into UDK, and adjusted the material's color, specularity, gloss, etc until I got the results below.