Quote: "well, first I tried a raised floor made out of segments, but when I tested the AI were halfway through the floor, at which point I realized I forgot to move them up
I moved them up, and they'd fight me, but they ignored all the entities. "
Are the entities that you use in this game are stock? Or they are self made? If self made maybe there is a problem with the collision? Try to double check, or sometimes it's just a bug, I also experienced this kind of problem in the first digmaan, it is where the aliens pass through walls and entities, I just put the invisible wall and it works. I don't know if this will work for you but maybe you could try it.
Quote: "then I tried using one large segment floor made to cover the whole ground area. that didn't work either, they didn't even move."
I experienced that problem too, I just change the segment cause, I don't know what to do anymore with them lol, trust me it's really a headache I remove the segment of the whole level and put new ones. xD
Quote: "after that I tried using an entity floor, but each one had shadows oddly placed on it, and the enemies wouldn't move."
It is because of the shadows I guess, fpsc thinks the shadows are solid, I sometimes encountered it to some entities I have here, maybe removing the shadow will do, however it will lessen the quality of the level design.
Quote: "then I tried lowering the traintrack floor, but that caused culling problems in that the rest of the map was constantly rendered, causing for polycounts over my max limit of 130k during a gunfight."
That hurts... try using stock segments and I already made a level with such train rails and the level of the waiting area is higher and it works. Just used the stock segments.
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Anyway I do not know and I am not sure if it will all work to you, but it works for me. Are you using any mod? Cause I'm not. Some mods also giving fpsc some problems.
Hope this helps, by the way, can you visit my wip, I guess I need your opinion on level designs, I really wanted to make my team's game great. And O,If you need some personalized huds, you can ask for my help, I can even lend you my compass or create a new one for you. Don't worry it's free of charge, just wanna help great artists like you.
work in progress