$moss enable

$moss_enable is a material shader parameter available in Black Mesa.

Moss shader example with LightmappedGeneric, for $moss_texture used xen/moss00_d.

Moss shader example with VertexLitGeneric, for $moss_texture used models/props_xen/moss_test/bubblemoss.

This is procedural moss implementation, which is triplanar projection shader that allows you to project additional texture that mixes with normalmap. This shader available for VertexLitGeneric, LightmappedGeneric and Lightmapped_4WayBlend shaders. It was created during development of Xen for Black Mesa and was designed to simulate presence of moss on surface.

For VertexLitGeneric, it uses the specified texture. For LightmappedGeneric and Lightmapped_4WayBlend, instead of using the texture itself for moss, this shader takes color that most of the texture consists of and then applies color to the surface according to the parameters specified in .vmt. All parameters works in the same way for both shaders.

In Black Mesa it was used for models\props_xen\moss_test\sphereofchon.mdl and models\props_xen\moss_test\test_moss001.mdl models. Both using the models/props_xen/moss_test/bubblemoss texture. The final version of the game doesn't use this shader in any of the maps. May be incompatible with some shaders (as it was with $phong).

This shader was used in Black Mesa: Blue Shift. Besides moss, it was also used for dust caps and other small details.

This shader also should be good for a snow layer.

Note:There is no Hammer preview for this shader.

Bug:This shader doesn't blend with new specular and $phong.

Examples.

An example with LightmappedGeneric. The specular should be yellow instead of white. An example with VertexLitGeneric. The specular should be green instead of white.

Parameters and Effects

$moss_enable <boolean>

Toggle moss between enabled and disabled state. 1 - enabled, 0 - disabled.

$moss_texture <texture>

For LightmappedGeneric, defines a diffuse texture that will use moss for color. For VertexLitGeneric, defines a diffuse texture that will use moss and mix with normalmap.

Examples.

metal/metalgrate013a (LightmappedGeneric) dev/dev_ram_512_red (LightmappedGeneric) xen/moss00_d (LightmappedGeneric)

$moss_ref_direction <vector3>

Defines direction for moss, the numbers can be negative. Works in the same way for VertexLitGeneric.

Examples.

$moss_ref_direction "[1 0 0]" $moss_ref_direction "[0 1 0] $moss_ref_direction "[0 0 1]

$moss_angle_theta <float>

Inner angle value. With LightmappedGeneric, works properly only on displacement surfaces. Results depend on $moss_angle_phi and $moss_angle_falloff. Works in a similar way for VertexLitGeneric.

Examples.

$moss_angle_theta 1, $moss_angle_phi 10, $moss_angle_falloff 0.5. $moss_angle_theta 5, $moss_angle_phi 10, $moss_angle_falloff 0.5. $moss_angle_theta 10, $moss_angle_phi 10, $moss_angle_falloff 0.5

$moss_angle_phi <float>

Outer angle value. With LightmappedGeneric, works properly only on displacement surfaces. Results depend on $moss_angle_theta and $moss_angle_falloff. Works in similar way for VertexLitGeneric.

Examples.

$moss_angle_theta 50, $moss_angle_phi 50, $moss_angle_falloff 0.5. $moss_angle_theta 50, $moss_angle_phi 100, $moss_angle_falloff 0.5. $moss_angle_theta 50, $moss_angle_phi 200, $moss_angle_falloff 0.5.

$moss_angle_falloff <float>

Falloff value. With LightmappedGeneric, works properly only on displacement surfaces. Results depend on $moss_angle_phi and $moss_angle_theta. Works in similar way for VertexLitGeneric.

Examples.

$moss_angle_theta 10, $moss_angle_phi 200, $moss_angle_falloff 0.5. $moss_angle_theta 10, $moss_angle_phi 200, $moss_angle_falloff 10 $moss_angle_theta 10, $moss_angle_phi 200, $moss_angle_falloff 500

$moss_blend_factor <float>

Moss blend factor. Use values from 0 to 1, others do not work correctly.

Examples.

$moss_blend_factor 0.5 $moss_blend_factor 0.8 $moss_blend_factor 1.0

$moss_scale <float>

Scale for moss. Deprecated and non-functional. Use $seamless_scale instead.

$moss_scale_turn_on_absolute <boolean> 

Toggle moss scale between enabled and disabled state. 1 - enabled, 0 - disabled. Affects nothing at least in Black Mesa: Definitive Edition.

$seamless_scale <float>

This parameter scales texture for this shader.

Examples.

$seamless_scale 0 $seamless_scale 0.003

See also

• New Specular
• BlackMesa XenEngine: Part1 – Heavily Modified Source Engine (page from Black Mesa developer about Black Mesa engine, better known as XenEngine)