{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "definitions": {
        "color_rgb": {
            "type": "object",
            "properties": {
                "r": {
                    "type": "number",
                    "minimum": 0,
                    "maximum": 1,
                    "default": 1
                },
                "g": {
                    "type": "number",
                    "minimum": 0,
                    "maximum": 1,
                    "default": 1
                },
                "b": {
                    "type": "number",
                    "minimum": 0,
                    "maximum": 1,
                    "default": 1
                }
            },
            "description": "color value in u3m standard colorspace",
            "additionalProperties": false,
            "required": [
                "r",
                "g",
                "b"
            ]
        },
        "uuid4": {
            "description": "UUID4 (variant-1) represented as string with or without {} - see https://en.wikipedia.org/wiki/Universally_unique_identifier",
            "type": "string",
            "pattern": "^((([0-9a-fA-F]){8}-([0-9a-fA-F]){4}-4([0-9a-fA-F]){3}-[89AaBb]([0-9a-fA-F]){3}-([0-9a-fA-F]){12})|(\\{([0-9a-fA-F]){8}-([0-9a-fA-F]){4}-4([0-9a-fA-F]){3}-[89AaBb]([0-9a-fA-F]){3}-([0-9a-fA-F]){12}\\}))$"
        },
        "relative_file_path": {
            "description": "relative path (from this file) to an other file",
            "type": "string",
            "pattern": "^((?!(\\.\\.|\\.|\\~|(([cC][oO][nN]|[pP][rR][nN]|[aA][uU][xX]|[cC][lL][oO][cC][kK]\\$|[nN][uU][lL]|[cC][oO][mM][1-9]|[lL][pP][tT][1-9])(\\.[^\\/]*)?))\\/)([^\\x00-\\x1F<>:\"\\/\\\\|\\$\\%]{0,254}[^\\x00-\\x1F<>:\"\\/\\\\|\\$\\%\\.\\x20|]\\/))*(?!(\\.\\.|\\.|\\~|(([cC][oO][nN]|[pP][rR][nN]|[aA][uU][xX]|[cC][lL][oO][cC][kK]\\$|[nN][uU][lL]|[cC][oO][mM][1-9]|[lL][pP][tT][1-9])(\\..*)?))$)([^\\x00-\\x1F<>:\"\\/\\\\|]{0,254}[^\\x00-\\x1F<>:\"\\/\\\\\\.\\x20|]$)$"
        },
        "optional_relative_file_path": {
            "description": "relative path (from this file) to an other file or null",
            "type": [
                "string",
                "null"
            ],
            "default": "null",
            "$ref": "#/definitions/relative_file_path"
        },
        "length_measurement": {
            "type": "number",
            "minimum": 0,
            "description": "length in mm"
        },
        "optional_length_measurement": {
            "type": [
                "number",
                "null"
            ],
            "minimum": 0,
            "default": "null",
            "description": "length in mm"
        },
        "optional_mass_per_area_measurement": {
            "type": [
                "number",
                "null"
            ],
            "minimum": 0,
            "default": "null",
            "description": "weight per area in g/m2"
        },
        "composition_part": {
            "type": "object",
            "properties": {
                "ratio": {
                    "type": "number",
                    "minimum": 0,
                    "maximum": 1
                },
                "type": {
                    "enum": [
                        "unknown",
                        "other",
                        "Abaca",
                        "Acetate",
                        "Acrylic",
                        "Alfa",
                        "Alginate",
                        "Alpaca",
                        "Aluminium",
                        "Angora",
                        "Aramid",
                        "Beaver",
                        "Camelhair",
                        "Cashmere",
                        "Cotton",
                        "Cupro",
                        "Elastane",
                        "Guanaco",
                        "Hardware",
                        "Hemp",
                        "Jute",
                        "Linen",
                        "Llama",
                        "Lycra",
                        "Lyocell",
                        "Meril",
                        "Metallic Fibre",
                        "Metallised Polyester",
                        "Micropolypch",
                        "Modacrylic",
                        "Modal Cotton",
                        "Modal",
                        "Mohair",
                        "Neoprene",
                        "Nylon",
                        "Organic cotton",
                        "Polyacryl",
                        "Polyamid",
                        "Polyester",
                        "Polyethylene",
                        "Polypropylen",
                        "Polytaslan",
                        "Ramie",
                        "Rayon",
                        "Recycled Cotton",
                        "Recycled Polyamide",
                        "Recycled Polyester",
                        "Silk",
                        "Spandex",
                        "Tactel",
                        "Triacetate",
                        "Vicugna",
                        "Vinyl",
                        "Virgin Wool",
                        "Wild Silk",
                        "Wool",
                        "Yack"
                    ]
                },
                "name": {
                    "type": [
                        "string",
                        "null"
                    ],
                    "description": "user defined additional name e.g. bio-cotton"
                }
            },
            "additionalProperties": false,
            "required": [
                "ratio",
                "type",
                "name"
            ]
        },
        "material_type": {
            "type": [
                "object",
                "null"
            ],
            "default": "null",
            "properties": {
                "type": {
                    "enum": [
                        "unknown",
                        "other",
                        "Artwork",
                        "Elastics",
                        "Knit",
                        "Leather",
                        "Metal",
                        "Seam",
                        "Wood",
                        "Woven"
                    ]
                },
                "name": {
                    "type": [
                        "string",
                        "null"
                    ],
                    "description": "user defined additional name e.g. veal-leather"
                }
            },
            "additionalProperties": false,
            "required": [
                "type",
                "name"
            ]
        },
        "construction": {
            "type": [
                "object",
                "null"
            ],
            "default": "null",
            "properties": {
                "type": {
                    "enum": [
                        "unknown",
                        "other",
                        "1 x 1 flatknit",
                        "1 x 1 rib",
                        "2 x 2 rib",
                        "4 x 2 rib",
                        "Canvas",
                        "Dobby",
                        "Doubleknit",
                        "Doubleweave",
                        "Engineered",
                        "Fleece",
                        "French terry",
                        "Interlock",
                        "Jacquard",
                        "Mesh",
                        "Oxford",
                        "Pique",
                        "Plain weave",
                        "Polarfleece",
                        "Poplin",
                        "Raschel",
                        "Ripstop",
                        "Satin",
                        "Single jersey",
                        "Spacer",
                        "TafFeta",
                        "Terry loop",
                        "Towel",
                        "Tricot",
                        "Twill - left hand (S)",
                        "Twill - right hand (Z)",
                        "Twill",
                        "Velour",
                        "Waffle"
                    ]
                },
                "name": {
                    "type": [
                        "string",
                        "null"
                    ],
                    "description": "user defined additional name e.g. woven"
                }
            },
            "additionalProperties": false,
            "required": [
                "type",
                "name"
            ]
        },
        "image": {
            "type": "object",
            "properties": {
                "width": {
                    "$ref": "#/definitions/length_measurement"
                },
                "height": {
                    "$ref": "#/definitions/length_measurement"
                },
                "dpi": {
                    "type": "object",
                    "properties": {
                        "x": {
                            "type": "number",
                            "minimum": 0
                        },
                        "y": {
                            "type": "number",
                            "minimum": 0
                        }
                    },
                    "additionalProperties": false,
                    "required": [
                        "x",
                        "y"
                    ]
                },
                "path": {
                    "$ref": "#/definitions/relative_file_path",
                    "description": "relative path to the image file"
                },
                "repeat": {
                    "type": "object",
                    "properties": {
                        "rotation": {
                            "type": "number"
                        },
                        "mode": {
                            "enum": [
                                "normal",
                                "mirror_x",
                                "mirror_y",
                                "mirror_xy"
                            ]
                        }
                    },
                    "additionalProperties": false,
                    "required": [
                        "rotation",
                        "mode"
                    ]
                }
            },
            "additionalProperties": false,
            "required": [
                "repeat",
                "dpi",
                "path",
                "width",
                "height"
            ]
        },
        "color_texture": {
            "type": [
                "object",
                "null"
            ],
            "properties": {
                "mode": {
                    "enum": [
                        "add",
                        "subtract",
                        "multiply",
                        "divide",
                        "max",
                        "min",
                        "overlay"
                    ],
                    "default": "multiply"
                },
                "factor": {
                    "$ref": "#/definitions/color_rgb",
                    "description": "additional factor, in u3m standard colorspace"
                },
                "image": {
                    "$ref": "#/definitions/image",
                    "description": "color image, has to be converted to u3m standard colorspace before use"
                }
            },
            "additionalProperties": false,
            "required": [
                "factor",
                "image",
                "mode"
            ]
        },
        "texture_and_color": {
            "type": [
                "object"
            ],
            "properties": {
                "constant": {
                    "$ref": "#/definitions/color_rgb"
                },
                "texture": {
                    "$ref": "#/definitions/color_texture"
                }
            },
            "additionalProperties": false,
            "required": [
                "constant",
                "texture"
            ]
        },
        "normal_texture": {
            "type": [
                "object",
                "null"
            ],
            "properties": {
                "scale": {
                    "type": "number",
                    "default": 1.0,
                    "description": "scaling factor, multiplied to x & y component before renormalization"
                },
                "image": {
                    "$ref": "#/definitions/image",
                    "description": "3 channel image without colorspace (do not convert)!, may need renormalizing in the shader"
                }
            },
            "additionalProperties": false,
            "required": [
                "scale",
                "image"
            ]
        },
        "texture_and_normal": {
            "type": [
                "object"
            ],
            "properties": {
                "constant": {
                    "type": "object",
                    "properties": {
                        "x": {
                            "type": "number",
                            "minimum": -1,
                            "maximum": 1,
                            "default": 0
                        },
                        "y": {
                            "type": "number",
                            "minimum": -1,
                            "maximum": 1,
                            "default": 0
                        },
                        "z": {
                            "type": "number",
                            "minimum": -1,
                            "maximum": 1,
                            "default": 1
                        }
                    },
                    "description": "3 component vector, may need renormalizing in the shader",
                    "additionalProperties": false,
                    "required": [
                        "x",
                        "y",
                        "z"
                    ]
                },
                "texture": {
                    "$ref": "#/definitions/normal_texture"
                }
            },
            "additionalProperties": false,
            "required": [
                "constant",
                "texture"
            ]
        },
        "scalar_texture": {
            "type": [
                "object",
                "null"
            ],
            "properties": {
                "factor": {
                    "type": "number",
                    "default": 1.0
                },
                "offset": {
                    "type": "number",
                    "default": 0.0
                },
                "image": {
                    "$ref": "#/definitions/image",
                    "description": "grayscale image without colorspace (do not convert)!, if multiple channels are given has to be converted to grayscale by averaging the 3 channels"
                }
            },
            "additionalProperties": false,
            "required": [
                "factor",
                "offset",
                "image"
            ]
        },
        "texture_and_number_01_1": {
            "type": [
                "object"
            ],
            "properties": {
                "constant": {
                    "type": "number",
                    "minimum": 0,
                    "maximum": 1,
                    "default": 1
                },
                "texture": {
                    "$ref": "#/definitions/scalar_texture"
                }
            },
            "additionalProperties": false,
            "required": [
                "constant",
                "texture"
            ]
        },
        "texture_and_number_01_0": {
            "type": [
                "object"
            ],
            "properties": {
                "constant": {
                    "type": "number",
                    "minimum": 0,
                    "maximum": 1,
                    "default": 0
                },
                "texture": {
                    "$ref": "#/definitions/scalar_texture"
                }
            },
            "additionalProperties": false,
            "required": [
                "constant",
                "texture"
            ]
        },
        "texture_and_number_0": {
            "type": [
                "object"
            ],
            "properties": {
                "constant": {
                    "type": "number",
                    "default": 0
                },
                "texture": {
                    "$ref": "#/definitions/scalar_texture"
                }
            },
            "additionalProperties": false,
            "required": [
                "constant",
                "texture"
            ]
        },
        "texture_and_number_1d4": {
            "type": [
                "object"
            ],
            "properties": {
                "constant": {
                    "type": "number",
                    "default": 1.4
                },
                "texture": {
                    "$ref": "#/definitions/scalar_texture"
                }
            },
            "additionalProperties": false,
            "required": [
                "constant",
                "texture"
            ]
        },
        "texture_and_number_0d7": {
            "type": [
                "object"
            ],
            "properties": {
                "constant": {
                    "type": "number",
                    "default": 0.7
                },
                "texture": {
                    "$ref": "#/definitions/scalar_texture"
                }
            },
            "additionalProperties": false,
            "required": [
                "constant",
                "texture"
            ]
        },
        "texture_and_number_0d5": {
            "type": [
                "object"
            ],
            "properties": {
                "constant": {
                    "type": "number",
                    "default": 0.5
                },
                "texture": {
                    "$ref": "#/definitions/scalar_texture"
                }
            },
            "additionalProperties": false,
            "required": [
                "constant",
                "texture"
            ]
        },
        "preview_image": {
            "type": [
                "object",
                "null"
            ],
            "properties": {
                "width": {
                    "$ref": "#/definitions/length_measurement"
                },
                "height": {
                    "$ref": "#/definitions/length_measurement"
                },
                "dpi": {
                    "type": "object",
                    "properties": {
                        "x": {
                            "type": "number",
                            "minimum": 0
                        },
                        "y": {
                            "type": "number",
                            "minimum": 0
                        }
                    },
                    "additionalProperties": false,
                    "required": [
                        "x",
                        "y"
                    ]
                },
                "path": {
                    "$ref": "#/definitions/relative_file_path",
                    "description": "relative path to the image file"
                }
            },
            "additionalProperties": false,
            "required": [
                "dpi",
                "path",
                "width",
                "height"
            ]
        },
        "visualisation": {
            "type": [
                "object",
                "null"
            ],
            "default": "null",
            "properties": {
                "alpha": {
                    "$ref": "#/definitions/texture_and_number_01_1"
                },
                "anisotropy_value": {
                    "$ref": "#/definitions/texture_and_number_0"
                },
                "anisotropy_rotation": {
                    "$ref": "#/definitions/texture_and_number_01_0",
                    "description": "value is in percent, to get to degree, multiply by 360"
                },
                "clearcoat_value": {
                    "$ref": "#/definitions/texture_and_number_0"
                },
                "clearcoat_normal": {
                    "$ref": "#/definitions/texture_and_normal"
                },
                "clearcoat_roughness": {
                    "$ref": "#/definitions/texture_and_number_0"
                },
                "ior": {
                    "$ref": "#/definitions/texture_and_number_1d4"
                },
                "metalness": {
                    "$ref": "#/definitions/texture_and_number_01_0"
                },
                "normal": {
                    "$ref": "#/definitions/texture_and_normal"
                },
                "displacement": {
                    "$ref": "#/definitions/texture_and_number_0"
                },
                "roughness": {
                    "$ref": "#/definitions/texture_and_number_0d7"
                },
                "sheen_value": {
                    "$ref": "#/definitions/texture_and_number_0"
                },
                "sheen_tint": {
                    "$ref": "#/definitions/texture_and_number_0"
                },
                "specular_value": {
                    "$ref": "#/definitions/texture_and_number_0d5",
                    "description": "value is defined on the segment [0%, 8%] -> 0.0 equals 0%, and 1.0 equals 8%"
                },
                "specular_tint": {
                    "$ref": "#/definitions/texture_and_number_0"
                },
                "subsurface_radius": {
                    "$ref": "#/definitions/texture_and_number_0"
                },
                "subsurface_value": {
                    "$ref": "#/definitions/texture_and_number_0"
                },
                "transmission": {
                    "$ref": "#/definitions/texture_and_number_01_0"
                },
                "basecolor": {
                    "$ref": "#/definitions/texture_and_color"
                },
                "subsurface_color": {
                    "$ref": "#/definitions/texture_and_color"
                },
                "shader": {
                    "enum": [
                        "principled"
                    ]
                },
                "preview": {
                    "$ref": "#/definitions/preview_image"
                }
            },
            "additionalProperties": false,
            "required": [
                "alpha",
                "anisotropy_value",
                "anisotropy_rotation",
                "clearcoat_value",
                "clearcoat_normal",
                "clearcoat_roughness",
                "ior",
                "metalness",
                "normal",
                "displacement",
                "roughness",
                "sheen_value",
                "sheen_tint",
                "specular_value",
                "specular_tint",
                "subsurface_radius",
                "subsurface_value",
                "transmission",
                "basecolor",
                "subsurface_color",
                "shader",
                "preview"
            ]
        },
        "physics": {
            "type": [
                "object",
                "null"
            ],
            "default": "null",
            "properties": {
                "thickness": {
                    "$ref": "#/definitions/optional_length_measurement"
                },
                "weight": {
                    "$ref": "#/definitions/optional_mass_per_area_measurement"
                },
                "devices": {
                    "type": "object",
                    "properties": {
                        "fab": {
                            "$ref": "#/definitions/optional_relative_file_path",
                            "description": "relative path to the fab physics file"
                        }
                    },
                    "additionalProperties": false,
                    "required": [
                        "fab"
                    ]
                },
                "composition": {
                    "type": [
                        "object",
                        "null"
                    ],
                    "default": "null",
                    "properties": {
                        "parts": {
                            "type": "array",
                            "items": {
                                "$ref": "#/definitions/composition_part"
                            },
                            "minItems": 1,
                            "description": "must have at least 1 value & ratio must sum up to 1"
                        }
                    },
                    "additionalProperties": false,
                    "required": [
                        "parts"
                    ]
                },
                "material_type": {
                    "$ref": "#/definitions/material_type"
                },
                "construction": {
                    "$ref": "#/definitions/construction"
                }
            },
            "additionalProperties": false,
            "required": [
                "thickness",
                "weight",
                "composition",
                "devices",
                "material_type",
                "construction"
            ]
        },
        "metadata": {
            "type": [
                "object",
                "null"
            ],
            "default": "null",
            "properties": {
                "beproduct": {
                    "$ref": "#/definitions/optional_relative_file_path",
                    "description": "relative path to beproduct metadata file"
                },
                "centric": {
                    "$ref": "#/definitions/optional_relative_file_path",
                    "description": "relative path to centric metadata file"
                },
                "swatchbook": {
                    "$ref": "#/definitions/optional_relative_file_path",
                    "description": "relative path to swatchbook metadata file"
                }
            },
            "additionalProperties": true,
            "required": [
                "beproduct",
                "centric",
                "swatchbook"
            ]
        }
    },
    "type": "object",
    "properties": {
        "schema": {
            "enum": [
                "1.1"
            ]
        },
        "material": {
            "type": "object",
            "properties": {
                "id": {
                    "$ref": "#/definitions/uuid4"
                },
                "name": {
                    "type": "string",
                    "minLength": 1
                },
                "description": {
                    "type": "string",
                    "default": ""
                },
                "created": {
                    "type": "string",
                    "format": "date-time"
                },
                "modified": {
                    "type": "string",
                    "format": "date-time"
                },
                "front": {
                    "$ref": "#/definitions/visualisation",
                    "description": "if null, but back is not null, use back, if side is not null, use side, otherwise no visuals are available"
                },
                "back": {
                    "$ref": "#/definitions/visualisation",
                    "description": "if null, the values from front are used instead"
                },
                "side": {
                    "$ref": "#/definitions/visualisation",
                    "description": "if null, the values from front are used instead"
                },
                "physics": {
                    "$ref": "#/definitions/physics"
                },
                "metadata": {
                    "$ref": "#/definitions/metadata"
                }
            },
            "additionalProperties": false,
            "required": [
                "name",
                "id",
                "created",
                "modified",
                "front",
                "back",
                "side",
                "physics",
                "metadata",
                "description"
            ]
        },
        "custom": {
            "type": [
                "object",
                "null"
            ]
        }
    },
    "additionalProperties": false,
    "required": [
        "schema",
        "material",
        "custom"
    ]
}