Material Type File Specification

Material type files (*.materialtype) are in written JSON format and contain the following elements.

propertyLayout

• groups: A list of property groups that appear in the Inspector window of the Material Editor. Each group contains the following:
  • id: An identifier for this group that is unique to this material type. The value must be formatted in C-style.
  • displayName: The given name of this group that will appear in the Material Editor.
  • description: The given description of this group that will appear as tooltips in the Material Editor.

Note:

The general group is built-in and always available, even if there is no general group defined in the groups section. This group is typically used to contain any basic properties of this material type.

• properties: Defines the groups of properties that can be configured in a material file. Each group is defined as a key/value pair, where key is the group id, and value is an array of property definitions.

  Material properties support the following data types:

  • Bool
  • Int
  • UInt
  • Float
  • Vector2
  • Vector3
  • Vector4
  • Color
  • Image
  • Enum

shaders

An array of references to shader files (.shader). Each reference contains the following values.

• file: The path to the shader file. The path must be relative to the asset root or to the material type file.
• tag: A unique name for this shader item that can be used to reference the shader from other places in the material type definition. It must be a C-Style identifier.

In this example, we reference the ShadowMap and DepthPass shaders.

"shaders": [
    {
        "file": "../ShadowMap.shader",
        "tag": "shadowmap"
    },
    {
        "file": "../DepthPass.shader",
        "tag": "depth"
    }
]

functor

An array of material functors. Each one reads material property values, performs some logic or calculations, and sets shader inputs accordingly. These can be defined in Lua or C++. Each functor data contains the following:

• type: The name of the functor type. This will be “Lua” for custom Lua script functors, or the name of specialized functor type (defined in C++).

• args: An object containing key/value pairs of all the arguments to send to this functor. The attributes vary depending on functor type. For ‘Lua’ functors, there is a single ‘file’ argument that references the Lua file.

To do:

Need a list of available functor types and their expected arguments.

A GitHub issue has been created for this task here.

uvNameMap (optional)

This array lists default identifiers for mesh UV streams.

To do:

Need a document about UV streams.

A GitHub issue has been created for this task here.