[article] Sharp light from windows

This is a discussion topic for the article "Sharp light from windows" by DrGlass which can be found here

Article description:

Create a beam of light from a window

Simple premise but not doubt something a lot of people have been wondering how to achieve. By the way, your windows don't need to be opaque to make use of this effect - you can quite happily build a skybox in the shape of your "light tunnel" and it will look normal in game while still giving this lighting effect.

Ah finally I see how you created this effect!
Thanks because now I won't have to use that static model in the effects folder.

Well to be fair that is actually used to create a different effect. This tutorial explains how to get realistically shaped light spots from a window or other opening. The prop you are talking about is used to create visible "beams" of light. These two could easily be used together if the situation calls for it.

Nice tutorial. Concise yet detailed enough to be easily understood. The illustration is well done.

ReNo is right Habboi, this is used to create a light shape one the floor, though you could also use dustmolts to help with a beam affect.

Your little example is sorta confusing like the func_brush part it looks like a whole bunch of dffrent brushes(hence all the white lines) and it dosent work for me either

I"ll update the pic to make it more clear. You need to make a hole in your wall where you want your window to go, then place a 5 sided box against the hole in your wall. Then fill your hole with a func_brush, this will be your window. Hope this clears things up.

It might be good to make the lightmap scale on nearby faces (floor for example) to 4 scale so the lines are sharper if you desire.

Otherwise, nice

Ok its a little bit clearer now what you mean but whats it mean by nodraw, do i put a nodraw brush/texture?

Nodraw is a texture, you place it on a brush face that the play wont be able to see, so the engin doesn't draw the face and add to negative FPS (ever so slightly)

It's an interesting idea but i think i've got a better idea on how to do this: just put the spotlight inside the hall, right off the side of the window and place a func_illusionary rail wrapped in a texture with the rendernt 0 in the middle of tha hall, so that the light_spot shines on the it. You should obtain the same effect.

Not quite sure what you mean, if you use just a spot light for the light-thru-window affect then you wont get the shape on the floor.

If you mean to use the rail to cast the shadow, that would work... BUT you have no controle over how the shadow will be cast and the block light can be made to fit the window style.

It's not hard: you put a light_spot behind your window, which is a func_brush, and you make extra brushes where the beams/bars are meant to be in the window using the BLOCKLIGHT texture (which will thus cause shadows to be cast properly on the floor). Of course, you don't need this angled NODRAW/SKYBOX box behind it- a square block will do just fine.

True... you could just make a large box outside of the window, but if you had multible windows you'd need more than one box or the lighting wouldn't work.