An extension of the [page:MeshStandardMaterial] that allows for greater control over reflectivity.
			Note that for best results you should always specify an [page:.envMap environment map] when using this material.
		
		[page:Object parameters] - (optional) an object with one or more properties defining the material's appearance.
		Any property of the material (including any property inherited from [page:Material] and [page:MeshStandardMaterial]) can be passed in here.
		The exception is the property [page:Hexadecimal color], which can be passed in as a hexadecimal
		string and is *0xffffff* (white) by default. [page:Color.set]( color ) is called internally.
		
See the base [page:Material] and [page:MeshStandardMaterial] classes for common properties.
Clearcoat level, from *0.0* to *1.0*. Default is *0.0*.
How rough the clearcoat appears, from *0.0* to *1.0*. Default is *0.0*.
			Used to check whether this or derived classes are mesh physical materials. Default is *true*.
			You should not change this, as it used internally for optimisation.
		
An object of the form:
			
				{
					'STANDARD': ''
					'PHYSICAL': '',
			
				};
			
			This is used by the [page:WebGLRenderer] for selecting shaders.
		
		Degree of reflectivity, from *0.0* to *1.0*. Default is *0.5*.
		This models the reflectivity of non-metallic materials. It has no effect when [page:MeshStandardMaterial.metalness metalness] is *1.0*
		
See the base [page:Material] and [page:MeshStandardMaterial] classes for common methods.
[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]