Mark,
I added a red line for reference and tried again. I also added a solid for reference. As you can see, the terrain still does not become transparent. This is not shown in the video, but I also changed the element and level transparency but with no success.
I did find that changing the transparency of the material itself caused the terrain to be transparent (see screenshot). My goal, however, is to be able to quickly switch from opaque to transparent using the display styles, so having manually change to transparency of the material isn't what I'm looking for. Any other suggestions?
(Please visit the site to view this video)
Thanks again,
Matt