Here's a little update. I've been working on an alleyway that the player has to traverse in the first few moments of my Singleplayer series of maps. You have to clamber across ledges high off the ground whilst the Combine patrol below you.
It's using all stock HL2 materials, I really want to test my scripting skills! At the moment, Combine rush past the alleyway exit in APCs and on foot randomly, looks quite nifty. The player doesn't even really look that way, but if he chooses to do so, it's a bit of eye candy for him/her.
[Blocked Image: http://i50.photobucket.com/albums/f332/PogoP/SPmap3.jpg]
In this next image, it's at ground level. You never even go down to ground level, I haven't a clue why I even took a screenshot. Heh.
[Blocked Image: http://i50.photobucket.com/albums/f332/PogoP/SPmap2.jpg]
[Blocked Image: http://i50.photobucket.com/albums/f332/PogoP/SPmap1.jpg]