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Creating env_cubemap_fog in older Source2 Games.

This guide explains how to create a functional env_cubemap_fog in older Source 2 games. This applies to Half-Life: Alyx iconHalf-Life: Alyx and Steam VR iconSteam VR.

See also the env_cubemap_fog entity reference for its full keyvalue list.

warning

For Steam VR iconSteam VR, Method 1 is the way to go, since resourcecompiler has a bug where .vtex files, regardless of their settings, do not generate mipmaps, which are required for env_cubemap_fog to work properly.

Method 1​

info

If you change the texture in MaterialEditor, a new .vtex file will be generated, so you will need to set the new .vtex file again in the env_cubemap_fog entity in Hammer.

  1. Create your 2D skybox in MaterialEditor.
    met1

  2. Go to the AssetBrowser and search for your 2D skybox material. Right-click, then left-click on Asset Info, then left-click on Parent or Child assets, and copy the asset name.
    assetbrowsersrch
    assetbrowsersrch1
    assetbrowsersrch2

  3. Finally, copy the compiled asset name into the env_cubemap_fog entity in Hammer.
    hammercbmpfg1

Method 2​

  1. Create a .vtex file and set the
    "m_fileName" "string" "name_of_your_texture"
    to the relative path of your 2D skybox texture.
info

Your "m_outputFormat" "string" "compression_format" should always be BC7 (HDR block compression) or BC6H (high-quality RGB or RGBA block compression), since skyboxes are normally 16-bit or 32-bit images.

<!-- dmx encoding keyvalues2_noids 1 format vtex 1 -->
"CDmeVtex"
{
    "m_inputTextureArray" "element_array" 
    [
        "CDmeInputTexture"
        {
            "m_name" "string" "InputTexture0"
            "m_fileName" "string" "materials/my_textures/my_texture.png"    // Replace this string
            "m_colorSpace" "string" "srgb"
            "m_typeString" "string" "2D"
            "m_imageProcessorArray" "element_array" 
            [
                "CDmeImageProcessor"
                {
                    "m_algorithm" "string" "None"
                    "m_stringArg" "string" ""
                    "m_vFloat4Arg" "vector4" "0 0 0 0"
                }
            ]
        }
    ]
    "m_outputTypeString" "string" "2D"
    "m_outputFormat" "string" "BC7"
    "m_outputClearColor" "vector4" "0 0 0 0"
    "m_nOutputMinDimension" "int" "0"
    "m_nOutputMaxDimension" "int" "0"
    "m_textureOutputChannelArray" "element_array" 
    [
        "CDmeTextureOutputChannel"
        {
            "m_inputTextureArray" "string_array" [ "InputTexture0" ]
            "m_srcChannels" "string" "rgba"
            "m_dstChannels" "string" "rgba"
            "m_mipAlgorithm" "CDmeImageProcessor"
            {
                "m_algorithm" "string" "Box"
                "m_stringArg" "string" ""
                "m_vFloat4Arg" "vector4" "0 0 0 0"
            }
            "m_outputColorSpace" "string" "srgb"
        }
    ]
    "m_vClamp" "vector3" "0 0 0"
    "m_bNoLod" "bool" "0"
}

  1. Compile your material. This is done automatically. If not, go to the Asset Browser, search for your texture, right-click, and select Full Recompile.
    vtexcompile

  2. Finally, copy the compiled asset name into the env_cubemap_fog entity in Hammer.

Which method is better?​

It depends on your case. If your skybox has no modifications in MaterialEditor, such as brightness or exposure, then Method 2 is the better option, since it allows more control over the texture if you need to adjust lighting, resolution, etc.

Usually, you won’t need such tweaks, so Method 1 is recommended, and it is also more efficient since you only need one texture.

Preview in Hammer​

previewhammer