Volumetric Light

Hi i know this is a simple thing to do, but i want to have light radiating out of square holes in the sides of these buildings. so far i have the rectangular brushes as func_dustcloud with a light inside going out the window, but all that does is make little particles that go up and down in the light and you cant see the rectangular shape of the light itself. How can i do this? is there a texture im supposed to use?

I believe the entity you want ofr thats is a point_spotlight or
somethign along those lines. Position it and play around with the
properties till you get the effect you want.

Are you possibly trying to achieve the effect in the HL2sp in the train
station with the windows? Well that wasnt done with dust motes or a
brush entity, it was done with a model. Its called voulmetic light (or
something like that), but its in the effects folder in the models
section. Due note that yuo will need to change the settings a bit (eg:
no collisions and disable shadows)

the dust particles--- tie the brush(s) to a 'func_dustmotes' entity. in the properties, you can change how thick the dust is, as in how many little particles are floating around. depending on size of the brush, i reccomend 30-70. i believe 'func_dustcloud' or something like that is the more "cloud" type thing. as for the actual light hitting the ground dynamicaly with your dustmotes, that is acheived with a light_spot, and if your window texture had lines in it, you may consider putting 'nodraw' brushes in the places those lines are-- the light goes through the texture, but the nodraw brushes block light, creating contrast and dynamics on the surface the light is hitting. if you want distinct lines, set brightness to about 4000-9000, and the fading angles within 5 of each other. the constant property is also important, if the light goes a long way, this has to be very high, like 2000.

cool thanks!

oh i parented a point_spotlight onto an elite soldiers head and placed him in my dark map, its pretty cool cuz his eye emits red light (as little sense as that makes its cool). is there a way to reduce or increase the starting radius of the spotlight? could i make it be much much narrower?

yes, but for the sake of the search database, a new question should start a new thread.