Introduction to material properties

In your ShaderLabUnity’s language for defining the structure of Shader objects. More info
See in Glossary code, you can define material properties. A material property is a property that Unity stores as part of the material asset. This allows artists to create, edit, and share materials with different configurations.

If you use material properties:

• You can get or set the value of a variable in a ShaderA program that runs on the GPU. More info
  See in Glossary object by calling functions on the material (such as Material.SetFloat).
• You can view and edit the values using the material InspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, allowing you to inspect and edit the values. More info
  See in Glossary.
• Unity saves the changes that you make as part of the material asset, so they persist between sessions.

If you do not use material properties:

• You can still get or set the value of a variable in a Shader objectAn instance of the Shader class, a Shader object is container for shader programs and GPU instructions, and information that tells Unity how to use them. Use them with materials to determine the appearance of your scene. More info
  See in Glossary by calling a function on a material.
• There is no visual editor for these values.
• Changes do not persist between sessions.

The only times that you would normally not create a material property is if you want to set shader property values entirely using scriptsA piece of code that allows you to create your own Components, trigger game events, modify Component properties over time and respond to user input in any way you like. More info
See in Glossary (for example, if you are making procedural content), if the properties cannot be made into material properties, or if you don’t want them to be edited in the Inspector.

How property values are provided to shaders

Shader property values are found and provided to shaders from these places:

• Per-Renderer values set in MaterialPropertyBlock. This is typically “per-instance” data (e.g. customized tint color for a lot of objects that all share the same material).
• Values set in the MaterialAn asset that defines how a surface should be rendered. More info
  See in Glossary that’s used on the rendered object.
• Global shader properties, set either by Unity rendering code itself (see built-in shader variables), or from your own scripts (e.g. Shader.SetGlobalTexture).

The order of precedence is like above: per-instance data overrides everything; then Material data is used; and finally if shader property does not exist in these two places then global property value is used. Finally, if there’s no shader property value defined anywhere, then “default” (zero for floats, black for colors, empty white texture for textures) value will be provided.

Serialized and Runtime Material properties

Materials can contain both serialized and runtime-set property values.

Serialized data is all the properties defined in shader’s Properties block. Typically these are values that need to be stored in the material, and are tweakable by the user in Material Inspector.

A material can also have some properties that are used by the shader, but not declared in shader’s Properties block. Typically this is for properties that are set from script code at runtime, e.g. via Material.SetColor. Note that matrices and arrays can only exist as non-serialized runtime properties (since there’s no way to define them in Properties block).