This guide is a list of all VMT/material parameters that Source Filmmaker recognizes by default, sorted/organized by shader.

This guide is not useful for non-experts. It's a raw, sometimes description-less, list of material shader and parameter names, which will not be useful for someone who's not looking for exactly that.
Even experts will struggle to find this useful much of the time. Only extreme "power users" may find this to be particularly helpful.









For colors, vector2s, vector3s, and vector4s, it's possible to specify a single float that will get applied identically to each number of the variable.
For example, setting a color parameter to 0.5 becomes 50% red, 50% green, and 50% blue, being a grey colour.

If you want to adjust each number separately, you must separate the numbers by spaces and wrap the group of numbers between { and } if you want values to be divided by 255 (so that values 0-255 become 0%-100%), or between [] if you want values to be used as is (so that values 0.0-1.0 become 0%-100%).
For example, "{255 128 0}" is (almost) the same as "[1 0.5 0]", both of them being 100% red, 50% green, and 0% blue, which is an orange colour.

(Note that due to Source using a gamma value of 2.2, using 50% in a colour parameter will result in a RGB output of 186 when rendered, not 128. This can be overcome by taking the number (in range 0.0-1.0, not 0-255) and multiplying it by itself 2.2 times.
For example, if you want a RGB output of 128, then 128 / 255 = (roughly) 0.5, and 0.5 ^ 2.2 = (roughly) 0.21763764082, so you should use 0.21763764082 in the material.)


For multi-number values, matrices, as well as paths/strings that contain spaces, the value must be wrapped in quotes ("), or Source Filmmaker will only interpret the first part of it as a value.
For values and parameter/shader names that don't have spaces, quotes are optional.



The parameter lists have a "Default Value / Additional Information" column. The default value for the parameter in question is shown in italics at the top of that column in each row, sometimes with additional information below that.

The default values are determined by examining a blank material (consisting of simply "_", being an unrecognized shader with no parameters set) in the built-in material editor (accessible by using "toolload vmt" and "mat_edit [material path]" in the console).
However, despite being based on a blank material, the listed "default" value is not actually always default;

Some parameters, such as the VertexLitGeneric shader's $ambientocclusion, have different defaults depending on other parts of the material.
And other parameters (notably, but not only, textures) may act one way if they're set, and another way if they're unset, in which case setting them to their "default" value can have a different outcome compared to not setting them at all.
And yet other parameters, such as the EyeRefract shader's $dilation, have one value defined as the "default", yet choose to use a different value if the parameter isn't set. I will mark this with "despite X being listed as the default, Y is used if the parameter isn't defined" where I'm aware of this happening, but this likely also happens many places where I haven't noted that.

In the below list, "Shader Name" is the name of the shader, to be put at the beginning of a material, "Usage" explains what circumstances the shader can be used in, and "Additional Notes" is some extra information that might be nice to know. Not all shaders' usage is known/listed, and even the listed usage may occasionally be wrong or incomplete.

This is a list of material parameters that are recognized by Source Filmmaker regardless of which shader is being used. They might not all affect something in every shader, but they are technically recognized.

This is an addendum to the above sections, with some additional information that doesn't fit well anywhere else.


When adding override materials to a model's animation set in Source Filmmaker, there are a few attributes that will automatically be added to the override materials if certain parameters exist in the VMT files, to help you override the most commonly-overriden parameters faster.
It's worth noting that, unlike when you add a new attribute yourself, these parameters will take on their value from the material rather than being set to zero.

Here is a list of the 3 parameters that can have attributes automatically added:




While technically not shader parameters per se, the built-in material editor still lists these things, and so I'll include them here for completeness' sake.

Even though they're not directly shader parameters in and of themselves, they still affect how the material is rendered; Fallbacks tweak the parameters being used on lesser machines, material proxies can modify other parameters through math and the like, and the shader being used, while not a parameter of the shader, of course has a major impact on how the material is displayed.

Note that these "parameters" don't start with $, as they're not used by the shader itself.




The following parameters mean almost nothing(?) for any Source game nor Source Filmmaker directly, but are used by map-editing and -compiling tools for a few special effects, such as whether a specific brush is water or should display the skybox.

Note that these parameters start with %, not $, to indicate that they're used by map tools rather than the shaders themselves.
Additionally, note that there may be additional tool parameters that are recognized by map tools that aren't shown here, due to not being in Source Filmmaker's built-in material editor. This includes %tooltexture.

The CustomHero shader was used for DotA 2's hero models before that game was ported from the Source 1 Engine to the Source 2 Engine.
It can be thought of as an alternative to VertexLitGeneric.

A notable difference between the two is that with the CustomHero shader, $envmap is(?) dimmed by (a lack of) non-projected lighting, making it appear less overly bright in dark areas.

The DebugTangentSpace shader shows the surface's normal directions, relative to the world, in colour ranges of -100% to +100% (where anything less than 0% is just rendered as 0%).

The X value is rendered as red, Y as green, and Z as blue.

The EyeRefract shader is one of the two shaders that support the Source Engine's dynamic-UV-projection QC eye system, allowing a model to look around without having to rotate bones or use flexes to move the eyes about.
The other of the two shaders is Eyes, which isn't nearly as feature-rich as EyeRefract.

The eyes shader is one of the two shaders that support the Source Engine's dynamic-UV-projection QC eye system, allowing a model to look around without having to rotate bones or use flexes to move the eyes about.
The other of the two shaders is EyeRefract, which is much more feature-rich than eyes.

The Infected shader is used by Left 4 Dead 2's common infected/zombies, allowing them to have randomly coloured clothing and other minor randomness, plus allowing two(?) ellipsoids to be cut away, for stuff like arbitrarily-positioned axe cuts.

This shader uses $basetexture as a series of masks, rather than a diffuse texture/albedo.

The LightmappedGeneric shader is the shader most commonly used for map brushes and displacements (map geometry). Lighting can be pre-calculated and baked into lightmaps, which this shader supports, allowing realistic lighting and shadows on materials using this shader. This shader supports many different effects.

The LightmappedReflective shader can use an extra render pass to create mirror-like reflections on a flat plane (which can span multiple different surfaces/triangles if needed, as long as it's a single plane).
These reflections unfortunately don't support Source Filmmaker's SSAO on models within them.

The Modulate shader is special in that, instead of replacing the existing background with its output, it multiplies the background by its output.
It can be used on brushes (accepting lightmaps), models, and maybe more?

The paintblob shader is very volatile. Even using the default parameter values will result in Source Filmmaker crashing when trying to render it (although this might depend on where the material is used?). However, its parameters and their defaults are still listed here for completeness' sake, even if the shader is unusable.

The ParallaxTest shader does parallax-mapping, allowing a flat surface to appear to have depth. However, as it's rendered full-bright(?), an additional material using the Modulate shader should be laid on top to fake shading.

This shader uses $basetexture's alpha channel as a height-map, where opaque parts are at the surface and transparency sets how deep the parallax effect is.

Based on the shader name, the ParticleLitGeneric_DX9 shader is a DirectX 9 fallback for a shader called ParticleLitGeneric, however no such shader is included with Source Filmmaker by default.
This guide doesn't cover other fallback shaders' parameters, but I will make an exception here as there's no "main" shader in this case.

The Patch "shader" is not actually a valid or recognized shader, however it can still be used at the start of a material. This is because that Patch is defined in the engine code rather than being compiled as a shader.
It can be used to load/inherit a different material as a base, optionally letting you add/replace parameters of the "child" material while not affecting the "parent" material.

To use the Patch "shader", start off with "Patch" at the beginning of the material, followed by a pair of curly brackets below (as usual with all materials). Then use these "parameters" (which notably don't start with $):




Since the Patch "shader" is special, it might be nice to see an example of how it's used.
In the below example, only $basetexture is different between the red and blue materials, so the blue one can easily inherit the other settings from the red one and simply change $basetexture, like so:

The Refract shader displaces/distorts/refracts pixels rendered behind this material, in a similar way to water, but doesn't have dynamic reflections, and so can be used on non-flat geometry without consequences.

It requires(?) $model to be set to 1 when used on models. It does not support models compiled with $subd.
If $basetexture is present, that sets which texture to refract, instead of using the existing rendered background.

The Sky shader is used for 2D skybox backgrounds, supporting HDR textures to allow a sun to appear bright with a low tone-map yet other areas to still appear detailed with a high tone-map.

$basetexture is used for LDR textures, while the below is for HDR textures.

The UnlitGeneric shader is the most commonly-used unshaded shader, intended for use by things that are meant to appear equally bright in all cases.
It can be used by brushes, material overlays, models, particles, and likely much more than that.

The UnlitTwoTexture shader is an unshaded brush(?) and model shader, with support for a second texture that can be transformed independently and blends multiplicatively with $basetexture.

This effect can also be achieved with the UnlitGeneric shader, using $detail for the second texture, $detailblendmode set to 8 (or to 0 along with $color 0.5), $detailscale set to 1, and $detailtexturetransform to transform the second texture.
However, UnlitGeneric doesn't support Team Fortress 2's Spy cloaking effect, which UnlitTwoTexture does.

$model must(?) be set to 1 when using this shader on a model.