ok,i'm new here, and to hammer, and i have this question/problem: i'm testing lighting in one map and by accident i didn't get the normal fullbright map, but instead a completely dark map which i liked. it helped me see the lights better. now for some reason it went to a fullbright map and i cannot see the lights whatsoever.if anyone can tell me how to make it compleatly dark(except for the light entity's),please do.

Try entering in mat_fullbright 0 into the console.

odd, the problem fixed itself, and i didn't enter the command,all i did was restart portal 2.

edit: i'll have to tinker around and find the issue, this problem was the exact opposite in my other test maps

Sometimes, after playing certain custom maps the fullbright turns to "1" automatically. I guess that happens because of a bad lighting settings in the map. When you quit the game and restart it, mat_fullbright's initial value is "0" That's why it got fixed when you restarted the game.

But a fullbright-like effect can happen to you also if you forgot to place env_cubemaps in your map. So check that out and don't forget to place them. You can check this effect easily by making a small room with a light entity in it, and compiling with and without a env_cubemap