Block Documentation - minecraft:material_instances

minecraft:material_instances is a JSON Object component that specifies the material instances for a block. The object contains a map that maps face or material_instance names in a geometry file to an actual material instance. You can assign a material instance object to any of these faces: up, down, north, south, east, west, or *. You can also give an instance the name of your choosing such as my_instance, and then assign it to a face by doing "north": "my_instance".

Default Value of the Component

This component is specified as a JSON Object, so it does not have a default value. You must provide at least the * material instance with a valid texture in order to use this component.

Material Instance

The minecraft:material_instances component contains a map of material instance names/face names to material instance definitions (JSON Objects). The material instance * is required and will be used for any materials that don't have a match.

Material Instance Parameters

The following are parameters of EACH material instance you provide:

Name	Default Value	Type	Description
ambient_occlusion	true	Boolean	Should this material have ambient occlusion applied when lighting? If true, shadows will be created around and underneath the block.
face_dimming	true	Boolean	Should this material be dimmed by the direction it's facing?
render_method	opaque	String	The render method to use. Must be one of these options: opaque - Used for a regular block texture without an alpha layer. Does not allow for transparency or translucency. double_sided - Used for completely disabling backface culling. blend - Used for a block like stained glass. Allows for transparency and translucency (slightly transparent textures). alpha_test - Used for a block like the vanilla (unstained) glass. Does not allow for translucency, only fully opaque or fully transparent textures. Also disables backface culling.
texture		String	Texture name for the material.

Example (using * and all parameters of a material instance)

"minecraft:material_instances": {
    "*": {
        "texture":"custom_texture",
        "ambient_occlusion": false,
        "face_dimming": false,
        "render_method": "alpha_test"
    }
}

Example (using faces and a custom named material instance)

"minecraft:material_instances": {
    "*": {
        "texture":"backupTexture"
    },
    "custom_sides": {
        "texture": "side_texture"
    },
    "up": {
        "texture": "top_texture"
    },
    "down": {
        "texture": "bottom_texture"
    },
    "north": "custom_sides",
    "south": "custom_sides",
    "east": "custom_sides",
    "west": "custom_sides"
}