ShaderLab: Properties

Shaders can define a list of parameters to be set by artists in Unity’s material inspector. The Properties block in the shader file defines them.

Syntax

Properties

Properties { Property [Property ...] }

Defines the property block. Inside braces multiple properties are defined as follows.

Numbers and Sliders

name ("display name", Range (min, max)) = number
name ("display name", Float) = number
name ("display name", Int) = number

These all defines a number (scalar) property with a default value. The Range form makes it be displayed as a slider between min and max ranges.

Colors and Vectors

name ("display name", Color) = (number,number,number,number)
name ("display name", Vector) = (number,number,number,number)

Defines a color property with default value of given RGBA components, or a 4D vector property with a default value. Color properties have a color picker shown for them, and are adjusted as needed depending on the color space (see Linear Lighting). Vector properties are displayed as four number fields.

Textures

name ("display name", 2D) = "defaulttexture" {}
name ("display name", Cube) = "defaulttexture" {}
name ("display name", 3D) = "defaulttexture" {}

Defines a 2D texture, cubemap or 3D (volume) property respectively.

Details

Each property inside the shader is referenced by name (in Unity, it’s common to start shader property names with underscore). The property will show up in material inspector as display name. For each property a default value is given after equals sign:

• For Range and Float properties it’s just a single number, for example “13.37”.
• For Color and Vector properties it’s four numbers in parentheses, for example “(1,0.5,0.2,1)”.
• For texture (2D, Cube) the default value is either an empty string, or one of built-in default textures: “white”, “black”, “gray” or “bump”.

Later on in the shader’s fixed function parts, property values can be accessed using property name in square brackets: [name]. For example, you could make blending mode be driven by a material property by declaring two integer properties (say “SrcBlend“ and ”DstBlend”), and later on make Blend Command use them: Blend [_SrcBlend] [_DstBlend].

Shader parameters that are in the Properties block are serialized as Material data. Shader programs can actually have more parameters (like matrices, vectors and floats) that are set on the material from code at runtime, but if they are not part of the Properties block then their values will not be saved. This is mostly useful for values that are completely script code-driven (using Material.SetFloat and similar functions).

Property attributes and drawers

In front of any property, optional attributes in square brackets can be specified. These are either attributes recognized by Unity, or they can indicate your own MaterialPropertyDrawer classes to control how they should be rendered in the material inspector. Attributes recognized by Unity:

• [HideInInspector] - does not show the property value in the material inspector.
• [NoScaleOffset] - material inspector will not show texture tiling/offset fields for texture properties with this attribute.
• [Normal] - indicates that a texture property expects a normal-map.
• [HDR] - indicates that a texture property expects a high-dynamic range (HDR) texture.
• [PerRendererData] - indicates that a texture property will be coming from per-renderer data in the form of a MaterialPropertyBlock. Material inspector changes the texture slot UI for these properties.

Example

// properties for a water shader
Properties
{
    _WaveScale ("Wave scale", Range (0.02,0.15)) = 0.07 // sliders
    _ReflDistort ("Reflection distort", Range (0,1.5)) = 0.5
    _RefrDistort ("Refraction distort", Range (0,1.5)) = 0.4
    _RefrColor ("Refraction color", Color) = (.34, .85, .92, 1) // color
    _ReflectionTex ("Environment Reflection", 2D) = "" {} // textures
    _RefractionTex ("Environment Refraction", 2D) = "" {}
    _Fresnel ("Fresnel (A) ", 2D) = "" {}
    _BumpMap ("Bumpmap (RGB) ", 2D) = "" {}
}

Texture property options (removed in 5.0)

Before Unity 5, texture properties could have options inside the curly brace block, e.g. TexGen CubeReflect. These were controlling fixed function texture coordinate generation. This functionality was removed in 5.0; if you need texgen you should write a vertex shader instead. See Implementing Fixed Function TexGen page page for examples.