$envmap

It most commonly used to approximate the specular reflections seen on smooth surfaces, such as metals, glass and plastics. This is achieved by mapping the vertex normals of a model to positions on a cubemap - specified by $envmap - and adding the sampled color from the cubemap to the model's surface. Typically, the cubemap is a simple, static "environment map" which has been pre-rendered (although a custom cubemap can be animated).
When $envmap is set to and has been run on the map, the engine will automatically select the environment map contained in the BSP which is nearest to the model as it moves through the world, providing a very rough approximation of dynamic reflections.
The other form of specularity supported by Source is the Phong type, which provides simpler reflections on both static and dynamic models.
== Availability ==
$envmap is available in all engine based games.
== Syntax==
$envmap env_cubemap
"env_cubemap" is typically used, which tells VBSP to swap in the name of the nearest env_cubemap when the map compiles. However, it is also possible to use a static cubemap image that has been manually created.
== Creating a custom static cubemap texture==
Creating a custom cubemap texture might be required for some circumstances and is used occasionally in some Valve models.
=== In VTFEdit===
For this to work you will need to have the 6 sides of the cubemap saved as individual textures in the correct orientation for it to appear correctly in the Source Engine. So some faces might need to be rotated either clockwise or counter clockwise. Each face will need to be mirrored horizontally before orientation.
To the right hand side of this page you will find two guide images to aid in properly rotating each side of your environment render.
Save one or both of those guides on your computer and then import your environment render onto it or recreate it in a smaller scale, then rotate your sides as instructed by the images.
Save every side as a separate image file, their names should be the number found on that specific square. This will ensure that the environment texture will be built correctly, as the numbers also represent the import order in VTFEdit.
Once you have all the image sides ready you can just import them all into VTFEdit and select "Environment Map". Texture format is up to you, generally DXT1 will do.
Enable the "Clamp S" and "Clamp T" texture flags.
Then just save it all as a .vtf file and use it in your VMT like so:
"$Envmap" "effects/my_cubemap"
"effects" is the usual folder for environments/cubemaps You may put yours anywhere you like
=== In VTEX===
VTEX will automatically mirror and orient your faces, you need only to provide correctly named textures. Name each file something like envmap001a*.tga, where * is put BK, FT, LF, RT, UP, or DN. If you took a cubemap screenshot in-game, this step will already by done, but to make them work properly with Vtex.exe you must use HDRShop (but before you need to change textures format to BMP, because HDRShop can only work with that kind of format) and then covert them to PFM files format.
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Create a text file the same name as your textures (e.g. envmap001a.txt). If building for HDR write in the following, otherwise leave it blank:
pfm 1 // read .pfm file instead of .tga
pfmscale 1 // higher values will result in a brighter sky
nocompress 1 // disable compression (HDR compression is only supported by skyboxes)
Put these files into materialsrc and then just drag-n-drop .txt file into vtex.exe and you should end up with a working cubemap! HDR envmaps will be named like envmap001a.hdr.vtf, and only need to exist to work.
== Parameters and Effects ==
== Console commands ==
: 
== See also ==
* $envmapmask (specular mask)
* $phong (for diffuse reflection)
* Cubemap
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Category:VMT Reflections