This is more so directed towards Mr2videocards as he is one of the only ones who may know what the problem is.
I have a few problems with particles in alien swarm that I do not have in source 2007.
First off, any normal mapped particle material to create refraction is black if it is merging with a brush such as water, or the floor. "for dripping purposes". So the particles turn black and refuse to refract any thing.
Then having particles lit by the surrounding light is another problem, because in dark places the fog/mist over water is full bright when it should be darken'd because there is no light hitting it, and the parts that are in the light of the tunnel should be tinted by that light like in source 2007. But this doesn't happen, even when my materials are the exact same.
Then, render_models will not work on any particle in game. I have a collapsing ceiling that needs small rocks falling and colliding with the ground, and they refuse to spawn in game.
I believe valve has completely corrupted the particle editor in alienswarm, and its really not fair that I dont have all the initializers and operators that they do, they're able to create vast effects that I cant because I don't have the proper tools to do so.
So if any one knows what the problem is with so many broken rendering problems in ASW, then please tell me.