Water (shader)

From Valve Developer Community

A custom Water material from Resistance And Liberation.

Real-time reflection of entities in Episode Two.

Water is one of the Source engine's most complex shaders. It creates animated, real-time reflective and refractive, fogged, normal-mapped water.

Expensive and cheap

Water materials fall into two groups: expensive and cheap. Expensive water reflects and refracts the world in real-time, while cheap water uses an $envmap and does not refract.

Users can disable expensive Water materials through their video options.

Above and below

Water actually requires two materials: one for above the surface and one for below. These materials are independent of each other, but of course for proper effect need to correlate in most areas.

Shader parameters

Textures

Tip: There is no $basetexture here. The surface is a combination of fog colour, animated bump map, and reflection.

$abovewater <bool>

Whether this material is used for above or below the water’s surface.

$bottommaterial <material>

Required field. This is the material (not texture) to use when underneath the water’s surface. The bottom material must have $reflecttexture and $abovewater disabled, but can otherwise do whatever it wants.

$bumpmap <texture>

$normalmap <texture>

A Du/dv map for DirectX 8 rendering ($bumpmap), and a bump map for DirectX 9 and above ($normalmap). These should be animated unless the water is to be perfectly still.

 Note: $normalmap is unique to Water. Everywhere else, $bumpmap is used and there are no du/dv maps.

$dudvframe <int>

$bumpframe <int>

Frame to start the animated du/dv map and bump map on, respectively. Somewhat confusingly, $bumpframe affects $normalmap, which should be pointing to a bump map.

Fog

$fogcolor <RGB matrix>

This is the color of the water’s volumetric fog. Generally this value should match the color used in the bottom material.

$fogenable <bool>

Enable volumetric fog for the water.

$fogend <float>

This is the distance in inches from the eye at which water fog ends.

$fogstart <float>

This is the distance in inches from the eye at which water fog starts.

Warning: This must be 0 for edge fading to work properly.

Reflection/Refraction

$envmap <env_cubemap / texture>

Provides reflections for cheap water. See $envmap

$forcecheap <bool>

Make this water cheap regardless of the water_lod_control entity's or user's settings. This will disable real-time reflection and instead use $envmap. Refraction is assumed to be opaquely the water fog color.

$forceexpensive <bool>

This forces the water to render itself as expensive, regardless of the map's water_lod_control or the user's settings.

$reflectamount <float>

This is the amount of warp for the reflection. Higher values produce more visible reflections.

$reflectentities <bool>

Make the water reflect entities. By default, no entities are reflected.

$reflecttexture <texture>

Texture to use for reflection. For real-time reflections, use _rt_WaterReflection.

Tip: Specify $refracttexture without $reflecttexture to get real-time refraction on $envmap reflections.

$reflecttint <RGB matrix>

This is the color tint for the real-time reflection and environment map.

$refractamount <float>

This is the amount of warp for the refraction. Higher values produce more warping.

$refracttexture <texture>

Texture to use for refraction. For real-time refractions, use _rt_WaterRefraction.

Tip: Specify $refracttexture without $reflecttexture to get real-time refraction on $envmap reflections.

$refracttint <RGB matrix>

This is the color of the refraction.

Warning: It is recommended that you set this to white or something close to white so that edge transitions work properly on DX9.

Other

%compilewater <bool>

This is needed to make a map using the material compile properly.

$surfaceprop water

Used by the physics system to define the surface as being water.

%tooltexture <texture>

Defines the texture Hammer will display in the material browser.

WaterLOD proxy

This connects the water_lod_control entity in a level to the water’s internal parameters. This must be declared in the material for the LOD mechanisms to work properly.

See also

• Adding Water (in Hammer)
• Creating a Waterfall Material