This article starts by introducing the syntax of ShaderLab, and the reference materials mainly come from the official manual.
As mentioned before, all Shaders in Unity are written in a declarative language (Declarative programming) called "ShaderLab". The real "shader code" is written in the CGPROGRAMsnippets of the same shader file. CGPROGRAM snippets are written in the general HLSL/Cg language.
Properties
Properties { Property [Property ...] }
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Format_Name
("Display Name",type) = defaultValue{options}
Attribute name("Display Name",type) = default value{optional parameters} -
Numbers and Sliders
Float , Int , Range (min, max)
all define number properties with default values. The Range format will display a slider from min to max.name ("display name", Range (min, max)) = number
name ("display name", Float) = number -
Colors and Vectors
define an RGBA color, or a 4D vector attribute.name ("display name", Color) = (number,number,number,number)
name ("display name", Vector) = (number,number,number,number) -
Textures
define a 2D texture , cubemap or 3D (volume) attribute.name ("display name", 2D) = "defaulttexture" {}
name ("display name", Cube) = "defaulttexture" {}
name ("display name", 3D) = "defaulttexture" {}- 2D: A texture of order size 2. This map will be converted into a color corresponding to each pixel based on the model UV after sampling, and finally displayed.
- Cube: Cube map texture. Simply put, it is a combination of six related 2D textures. It is mainly used for reflection effects (such as sky boxes and dynamic reflections) and will also be converted into samples of corresponding points.
- 3D: Unity supports 3D textures, used and created from shaders and scripts. Currently, 3D textures can only be created via scripts.
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细节
每个属性都是根据name引用的（在Unity中一般以下划线_开始），而在编辑器界面显示的是display name，等号后面指定了默认值：- 对于Range和Float其只是一个浮点数，color范围0~1
- Color和Vector是括号内的四个数
- 贴图（2D、Cube）默认值是一个空字符串，或者是内建的默认贴图：“white”, “black”, “gray” or “bump”.
之后在shader的fixed function部分，属性值可以通过方括号加属性名获取：[name]。
Properties块中的属性会被序列化成material数据，这对于在脚本控制值非常有用 (使用 Material.SetFloat 或类似函数). -
Property attributes and drawers
对之前的属性，都可以使用方括号指定可选的修饰（attributes），下面是一些Unity可以认出的修饰，或是可以自己指定（MaterialPropertyDrawer classes） 以控制它们在material inspector中如何被渲染。- [HideInInspector] 不在inspector显示
- [NoScaleOffset] 对于texture属性，不会显示贴图的 tiling/offset字段。
- [Normal] 指示一个贴图是normal-map。
- [HDR] 指示一个贴图是高动态范围（high-dynamic range (HDR)）贴图。
- [PerRendererData] 指示一个贴图是来自MaterialPropertyBlock格式的 per-renderer data 。
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