Programming Interaction with Entities in Hammer

[Aunvre]

I didn't know whether to put this in mapping or programming, but I decided to put it here.

Does anybody know how (or if) interaction with entities in a map are possible, and if so, how to do it? I'm programming a mod, and when the player's actions coincide with a set of parameters, I want their screen to get fuzzier the longer they are still following the parameters (and subsequently, the fuzziness fades as they stop).

There don't seem to be any tutorials on map entity/programming/scripting interaction out there.

I can program in C/C++ and Lua, I'd figure that those would be plenty...

If anybody had some ideas, then that would be awesome. Thanks.

[Puni]

Sorry I might have misunderstood what exactly you want but;

ent_fire entityname output delay?

This command allows you to interact with entities in source games. Works in console and have also used it in plugins for donator shops, levelling systems in CSS and more.