Skybox (2D)

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Revision as of 20:12, 10 March 2008 by Yrogerg77 (talk | contribs) (Creating a 2D Skybox)
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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.

Adding sky to a map

Simply texture a regular brush (not a brush entity) with the tools/toolsskybox texture. When in-game, the sky will show wherever the toolsskybox would be seen if it were a normal texture. The brushes with the sky texture do not need to be box-shaped.

Note.png Note: In HL2 the default skybox has visible seams. This is not your fault. See the next section for how to change the default.

Changing the displayed skybox

If you don't like the standard sky_wasteland2 sky, you can change it by setting the skybox name in Hammer's Map Properties dialog. Follow these steps:

  1. Make sure the correct map is opened.
  2. Go to the Map menu and choose Map Properties...
  3. Select the Skybox Texture Name field.
  4. Enter then name of the skybox you wish to display. You can find a list of available skyboxes in the Sky List.

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 $SKYNAME.vmt)
  3. After conversion, open the .txt and add:
 // Original shader: BaseTexture
 "$basetexture" "skybox/$SKYNAME"
 // stops error: "Can't load skybox file skybox/(skyboxname) to build the default cubemap!" 
 "$hdrbasetexture" "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.

Request: Could someone please make this section more specific? Are these instructions required for all 2D skyboxes or only those of people who are creating their own mod? As someone with no experience this is not clear to me. Does a normal TF2 or HL2 mapper need to do this to create a simple 2D skybox?"

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.

See also

Environment articles:
Skies and environment maps Skybox (2D)Skybox (3D)HDR SkiesSkybox with TerragenSkybox with Terragen - AdvancedList of skies
Terrain and displacement mapping DisplacementsHoles in displacementsDigital Elevation Models