In Unity, when you work with shaders that are part of the graphics pipeline, you usually work with instances of the ShaderA program that runs on the GPU. More info
See in Glossary class. An instance of the
Shader class is called a Shader object.
A Shader object is a Unity-specific way of working with shader programs; it is a wrapper for shader programs and other information. It lets you define multiple shader programs in the same file, and tell Unity how to use them.
|Feature name||Built-in Render Pipeline||Universal Render Pipeline (URP)||High Definition Render Pipeline (HDRP)||Custom SRP|
A Shader object contains shader programs, instructions for changing settings on the GPU (collectively called the render state), and information that tells Unity how to use them.
You use Shader objects with materialsAn asset that defines how a surface should be rendered. More info
See in Glossary to determine the appearance of your sceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary.
You can create Shader objects in two ways. Each has its own type of asset:
Whichever way you create your Shader object, Unity represents the results in the same way internally.
A Shader object has a nested structure. It organizes information into structures called SubShaders and Passes. It organises shader programs into shader variants.
A Shader object contains:
SubShaders let you separate your Shader object into parts that are compatible with different hardware, render pipelines, and runtime settings.
A SubShader contains:
You can also define additional information, such as render state that is common to all of its Passes. For information on everything you can define in a SubShader, see ShaderLab: defining a SubShader.
A Pass contains:
You can also define additional information such as a name. For information on everything you can define in a Pass, see ShaderLab: defining a Pass.
The shader programs that a Pass contains are organised into shader variants. Shader variants share common code, but have different functionality when a given keyword is enabled or disabled.
The number of shader variants in a Pass depends on how many keywords you define in your shader code, and the target platform. Each Pass contains at least one variant.
For more information, see Shader variantsA verion of a shader program that Unity generates according to a specific combination of shader keywords and their status. A Shader object can contain multiple shader variants. More info
See in Glossary.
This is a high-level description of how Unity uses Shader objects to render geometry, in all render pipelines.
Before Unity uses a Shader object:
When Unity first renders geometry using the Shader object, or when the shader LOD value or active render pipeline changes:
Unity can identify geometry that uses the same shader variant and organize it into batches for more efficient renderingThe process of drawing graphics to the screen (or to a render texture). By default, the main camera in Unity renders its view to the screen. More info
See in Glossary. Once per frame, for every batch of geometry: