How to add skybox?

[FourThing]

I cant see any button to skybox :o

[BJK51]

2D or 3D skybox?

For a standard skybox, you have to surround the map with nodraw brushes leaving no hole to the void, prerrably as close to the level as possible. Do not use a hollowed box in any circumstance. For testing purposes, you may use the cordon tool (http://developer.valvesoftware.com/wiki/Cordon).

For a 3D skybox, place a sky_camera entity, and a reference brush helps but make sure the sky_camera is at 0,0,0 before shrinking it .0625 with the reference brush.

http://developer.valvesoftware.com/wiki/3d_skybox

[bgp157]

If you have trouble you could always just take the blue skybox texture, make a box around the map, and hollow it out to -32. It's not recommended but it still works

[Buzzaard]

There is no button you create it by putting brushes above and on the sides of your map just like creating walls. Then you use the texture button and use the materrial tools/toolsskybox or tools/toolsskybox2d to texture it on the inside.