loadPMD( url, onLoad, onProgress, onError ) {

			const parser = this._getParser();

			this.loader.setMimeType( undefined ).setPath( this.path ).setResponseType( 'arraybuffer' ).setRequestHeader( this.requestHeader ).setWithCredentials( this.withCredentials ).load( url, function ( buffer ) {

				onLoad( parser.parsePmd( buffer, true ) );

			}, onProgress, onError );

		}
Loads .pmd file as an Object.

@param {string} url - url to .pmd file
@param {function} onLoad
@param {function} onProgress
@param {function} onError