Skybox (2D)

In Source, the skybox is a series of six images, joined together to make a cube. The cube is then locked to the player's viewpoint and acts as the most distant area of a map, usually the sky. Because the skybox is fixed to the player's viewport, it never changes perspective, allowing the cube to appear as a seamless whole.

Creating a 2D skybox

1. Prepare your TGA files (i.e. skynameBK.tga, skynameFT.tga, skynameUP.tga, skynameDN.tga, skynameRT.tga, skynameLF.tga)
2. Convert the TGA images to VTF (this will create a $SKYNAME.txt which you will later edit then rename to $SKYNAME.vmt)
3. After conversion, open the .txt and add:

"UnlitGeneric"
 {
 // Original shader: BaseTexture
 "$basetexture" "skybox/$SKYNAME"
 "$nofog" 1
 $ignorez 1
 }

• For each file, append the appropriate image tag to the sky name (i.e. bk, ft, rt, lf, up, dn)
• Rename the .txt files to .vmt
• Now go into your mod's materials folder and create the folder skybox.
• Copy your new VTF and VMT files into the skybox folder.
• In Hammer, go to Map > Map Properties > Skybox Texture Name and type in your skyname, without the side tags.

Creating a 2D skybox for Goldsource, using Source

It is possible to create an area of your map into a 2D Skybox to be used in Goldsource (the HL1-engine). Here's an simple example:

1. Create a large outdoor area with some displacementmaps and treelines, and fog to hide the edges. Lets call it carrotjuice .
2. Load the map ingame and turns cheats on ( sv_cheats 1 ).
3. Activate the noclip-mode by simply opening the console and enter "noclip" and hit Enter.
4. Fly to the center of where you want the skybox.
5. Open up the console and type "mat_envmaptgasize 256", hit Enter.
6. Now type "envmap" and press Enter. Now, 6 TGA-files are now created and saved into a folder named "cubemap_screenshots" in your modfolder ( i.e. for HL2DM: Steam\SteamApps\youraccount\Half-Life 2 Deathmatch\hl2mp ).

Since the mapname was carrotjuice , the name of the 6 TGA-files are as following:

carrotjuicert.tga (Right)
carrotjuiceft.tga (Front)
carrotjuicelf.tga (Left)
carrotjuicebk.tga (Back)
carrotjuiceup.tga (Up)
carrotjuicedn.tga (Down)

You can now copy or move these to your HL1-mods gfx\env-folder, to use it as skybox in a level.