oh, and garg is right about the visual mapping thing.
I admit there are people better than me in many cases, but understand that the HL engine is not of my own design as well as the entities and the like.
I don't understand it because i didn't make the engine myself and i don't know everything about it. Plus, i'm not too serious about all this because I can't make money off of it, it's a hobby, I use it more like a piece of artwork rather than entertainment, and it's a good way to construct my worlds.