data class Skin(var name: String? = null, val inverseBindMatrices: Int? = null, val joints: IntArray = IntArray(0), val skeleton: Int? = null, val extensions: JsonElement? = null, val extras: JsonElement? = null) : GLTFProperty
Although extrasMAY have any type, it is common for applications to store and access custom data as key/value pairs. Therefore, extrasSHOULD be a JSON object rather than a primitive value for best portability.