fromJSON(json, parent) {
        var obj = parent === undefined ? new THREE.ParametricBufferGeometry(
            json.parameters.func,
            json.parameters.slices,
            json.parameters.stacks
        ) : parent;

        BufferGeometrySerializer.prototype.fromJSON.call(this, json, obj);

        return obj;
    }
ParametricBufferGeometrySerializer
@author tengge / https://github.com/tengge1