Shader Docs

This section gives you an overview of shaders and their properties. For a detailed explanation, see Material properties.

Understanding and leveraging RED4 shaders

We do not have official documentation from CDPR about how shaders are used by artists. Thus any 2d/3d artist is looking at hundreds of black-box shaders with unknown usage. This is extremely demotivating for anyone looking to bring new assets to life with REDengine. The following list of tables is an attempt to make life easier for artists by using the community to document commonly used shaders.

About the documentation

• The name and path of each shader will be documented by the header.

• Next we are using a table for each texture parameter with the exact name listed by CDPR in the w2mg file, how REDengine uses each specific RGBA channel, and the usable range of the channel if not 0-1/0-255.

• When applicable, vertex color properties will be listed underneath the texture table with a similar format.

• Scalar, vector, color, and other properties will follow with their own unique description table.

• An asterisk (*) is used to notate some degree of uncertainty, or need for more independent testing.

Shaders

skin

base/materials/skin.mt

Texture	Red	Green	Blue	Alpha
Albedo	Color	Color	Color	?
SecondaryAlbedo	?	?	?	?
Normal	Normal	Normal	None	?
DetailNormal	Additive Normal	Additive Normal	None	?
Roughness	Roughness	None	MicroDetail mask (0.5-1)*	?
MicroDetail	Additive Normal	Additive Normal	None	?
TintColorMask	?	?	?	?
Detailmap_Stretch	Additive Normal	Additive Normal	None	?
Detailmap_Squash	Additive Normal	Additive Normal	None	?
EmmisiveMask	?	?	?	?
Bloodflow	?	?	?	?

Vertex Colors	Description
Red	Ambient Occlusion*
Green	Subsurface Scattering Mask
Blue	Improved Facial Lighting Mask

Properties	Description
SecondaryAlbedoInfluence	?
SecondaryAlbedoTintColorInfluence	?
DetailRoughnessBiasMin/Max	?
MicroDetailUVScale01/02	?
MicroDetailInfluence	Controls MicroDetail normal intensity
TintColor	?
TintScale	?
SkinProfile	?
EmissiveEV	?
CavityIntensity	?
BloodColor	?
DetailNormalInfluence	Controls DetailNormal normal intensity

Notes

• The DetailNormal texture contains generic normal details that are shared between most faces. This is not a tiling/procedural texture. The DetailNormalInfluence scalar parameter can be used to lower the intensity to simulate makeup or synthetic skin.\

• The MicroDetail texture contains a microblend tiling texture used to add procedural detail to the normal map. We believe the Roughness texture blue channel is used to mask parts of the face from exhibiting this detail, such as the lips, eyelids, and ears.

mesh_decal

base/materials/mesh_decal.mt

Texture	Red	Green	Blue	Alpha
DiffuseTexture	Color	Color	Color	Opacity Mask
SecondaryMask	?	?	?	?
NormalTexture	Normal	Normal	None	?
NormalAlphaTex	?	?	?	?
NormalsBlendingModeAlpha	?	?	?	?
RoughnessTexture	Roughness*	Roughness*	Roughness*	?
MetalnessTexture	Metalness*	Metalness*	Metalness*	?

Properties	Description
VertexOffsetFactor	?
DiffuseColor	Procedural Color
DiffuseAlpha	Alpha
UVOffsetX/Y	?
UVRotation	?
UVScaleX/Y	?
SecondaryMaskUVScale	?
SecondaryMaskUVInfluence	?
NormalAlpha	?
UseNormalAlphaTex	?
NormalsBlendingMode	?
RoughnessScale	?
RoughnessBias	?
MetalnessScale	?
MetalnessBias	?
AlphaMaskContrast	?
RoughnessMetalnessAlpha	?
AnimationSpeed	?
AnimationFramesWidth	?
AnimationFramesHeight	?
DepthThreshold	?

Notes

• DiffuseColor multiplies against the texture color to add procedural color

glass

base\materials\glass.mt

Texture	Red	Green	Blue	Alpha
GlassTint	Color	Color	Color	?
MaskTexture	?	?	?	?
Roughness	Roughness	Roughness	Roughness	?
Normal	Normal	Normal	Normal	?

Vertex Colors	Description
Red	Color
Green	Color
Blue	Color

Properties	Description
TintColor	Procedural Color
Opacity	Overall Opacity
OpacityBackFace	Opacity of back face
TintFromVertexPaint	Control how much vertex color will tint the glass color. If set to max value, vertex color will completely replace TintColor.
FrontFacesReflectionPower	How much front face reflect light
BackFacesReflectionPower	How much back face reflect light
IOR	Index of Refraction?
RefractionDepth	?
FresnelBias	?
GlassSpecularColor	Color of light reflected from glass
NormalStrength	Control how much normal map affects mesh
NormalMapAffectsSpecular	Control how much normal map affects reflected light
SurfaceMetalness	Metalness
MaskOpacity	?
GlassRoughnessBias	?
MaskRoughnessBias	?
BlurRadius	?
BlurByRoughness	?

Note

• There are a number of ways you can colorize your glass. GlassTint is the texture used to determine glass color. TintColor is procedural color. TintFromVertexPaint value determines how much vertex color affects the glass color. GlassTint seemingly has the highest priority, as in it will override other color parameters. Below is a test result from the process of making a glass wing.

How glass color is affected by different parameters

• There are many different other glass shaders, this one is just the most basic that is used for small objects.

television_ad

base\fx\shaders\television_ad.mt

Texture	Red	Green	Blue	Alpha
AdTexture*	Color	Color	Color	Color
DirtTexture	Color	Color	Color	Color

Properties	Description
TilesWidth*	How many tiles are on the horizontal axis of the sprite sheet
TilesHeight*	How many tiles are on the vertical axis of the sprite sheet
PlaySpeed	Speed of which animation will play
InterlaceLines	How much screen scanline is visible
PixelsHeight*	Height of sprite in pixel
EmissiveEV	Energy Voltage of light emission
EmissiveEVRaytracingBias	Energy Voltage of light emission by Raytracing
EmissiveDirectionality	?
EnableRaytracedEmissive	Enable Raytraced Emission
BlackLinesIntensity	?
BlackLinesRatio	?
BlackLinesSize	?
LinesOrDots	?
DistanceDivision	?
Metalness	?
Roughness	?
IsBroken	If enabled, the animation will have a broken TV overlay effect
UseFloatParameter	?
UseFloatParameter1	?
AlphaThreshold	?
DirtOpacityScale	Opacity of Dirt Texture
DirtRoughness	Roughness of Dirt
DirtUvScaleU	UV Scale of Dirt Texture
DirtUvScaleV	UV Scale of Dirt Texture
HUEChangeSpeed	?

Note

• AdTexture: TV screen will play looping animations that are actually sprites like a .gif. We believe this is for optimization purposes since videos are heavy.

• TilesWidth, TilesHeight, and PixelsHeight combine will help the game define the dimension of your tile (sprite) on the sprite sheet.

• You should calculate your sprite sheet dimension so it completely fits in a square sheet. For example, a simple dimension is 5x5 tiles with 300x300 pixel sprite. Such a dimension will produce animation with 25 frames of a square sprite.

• More examples of such sprite sheets can be found in the path below

base\environment\decoration\advertising\digital\textures\animated\textures

It's recommended that you use free tools like Ezgif.com to make .gif and convert it into a sprite sheet for AdTexture

AdTexture as Sprite Sheet Example. This is the Trauma Team news in the game.

• There are many screen shaders, this one is used for small TV screens.

If used cleverly with a properly done mesh, you can make use of this shader to put animation on your clothing or other items