json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "name": "Material Asset",
      "description": "asset.json specification for materials.",
      "type": "object",
      "properties": {
          "asset_type": {
              "type": "string",
              "pattern": "material"
          },
          "shader": {
              "type": "string",
              "description": "path to a shader asset"
          },
          "parameters": {
              "description": "The parameters to override from the shader",
              "type": "object",
              "patternProperties": {
                  ".*": {
                      "description": "The overrided value",
                      "anyOf": [
                          {
                              "type": "string"
                          },
                          {
                              "type": "array",
                              "items": {
                                  "type": "number"
                              },
                              "minItems": 2,
                              "maxItems": 4
                          },
                          {
                              "type": "number"
                          }
                      ]
                  }
              }
          }
      },
      "required": [
          "asset_type",
          "shader",
          "parameters"
      ]
  }
  