function MeshPhysicalMaterial( parameters ) {

		MeshStandardMaterial.call( this );

		this.defines = {

			'STANDARD': '',
			'PHYSICAL': ''

		};

		this.type = 'MeshPhysicalMaterial';

		this.reflectivity = 0.5; // maps to F0 = 0.04

		this.clearcoat = 0.0;
		this.clearcoatRoughness = 0.0;

		this.sheen = null; // null will disable sheen bsdf

		this.clearcoatNormalScale = new Vector2( 1, 1 );
		this.clearcoatNormalMap = null;

		this.transparency = 0.0;

		this.setValues( parameters );

	}
@author WestLangley / http://github.com/WestLangley

parameters = {
 reflectivity: <float>
 clearcoat: <float>
 clearcoatRoughness: <float>

 sheen: <Color>

 clearcoatNormalScale: <Vector2>,
 clearcoatNormalMap: new THREE.Texture( <Image> ),
}