<!-- SOLUV · part 206 -->
alue ) {

		if ( this._anisotropy > 0 !== value > 0 ) {

			this.version ++;

		}

		this._anisotropy = value;

	}

	/**
	 * Represents the intensity of the clear coat layer, from `0.0` to `1.0`. Use
	 * clear coat related properties to enable multilayer materials that have a
	 * thin translucent layer over the base layer.
	 *
	 * @type {number}
	 * @default 0
	 */
	get clearcoat() {

		return this._clearcoat;

	}

	set clearcoat( value ) {

		if ( this._clearcoat > 0 !== value > 0 ) {

			this.version ++;

		}

		this._clearcoat = value;

	}
	/**
	 * The intensity of the iridescence layer, simulating RGB color shift based on the angle between
	 * the surface and the viewer, from `0.0` to `1.0`.
	 *
	 * @type {number}
	 * @default 0
	 */
	get iridescence() {

		return this._iridescence;

	}

	set iridescence( value ) {

		if ( this._iridescence > 0 !== value > 0 ) {

			this.version ++;

		}

		this._iridescence = value;

	}

	/**
	 * Defines the strength of the angular separation of colors (chromatic aberration) transmitting
	 * through a relatively clear volume. Any value zero or larger is valid, the typical range of
	 * realistic values is `[0, 1]`. This property can be only be used with transmissive objects.
	 *
	 * @type {number}
	 * @default 0
	 */
	get dispersion() {

		return this._dispersion;

	}

	set dispersion( value ) {

		if ( this._dispersion > 0 !== value > 0 ) {

			this.version ++;

		}

		this._dispersion = value;

	}

	/**
	 * The strength of retroreflection, from `0.0` to `1.0`. A value of `1.0`
	 * evaluates the material's microfacet reflection with the view direction
	 * reflected about the surface normal, redirecting the specular lobe back
	 * toward the light source.
	 *
	 * @type {number}
	 * @default 0
	 */
	get retroreflectivity() {

		return this._retroreflectivity;

	}

	set retroreflectivity( value ) {

		if ( this._retroreflectivity > 0 !== value > 0 ) {

			this.version ++;

		}

		this._retroreflectivity = value;

	}

	/**
	 * The intensity of the sheen layer, from `0.0` to `1.0`.
	 *
	 * @type {number}
	 * @default 0
	 */
	get sheen() {

		return this._sheen;

	}

	set sheen( value ) {

		if ( this._sheen > 0 !== value > 0 ) {

			this.version ++;

		}

		this._sheen = value;

	}

	/**
	 * Degree of transmission (or optical transparency), from `0.0` to `1.0`.
	 *
	 * Thin, transparent or semitransparent, plastic or glass materials remain
	 * largely reflective even if they are fully transmissive. The transmission
	 * property can be used to model these materials.
	 *
	 * When transmission is non-zero, `opacity` should be  set to `1`.
	 *
	 * @type {number}
	 * @default 0
	 */
	get transmission() {

		return this._transmission;

	}

	set transmission( value ) {

		if ( this._transmission > 0 !== value > 0 ) {

			this.version ++;

		}

		this._transmission = value;

	}

	copy( source ) {

		super.copy( source );

		this.defines = {

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

		};

		this.anisotropy = source.anisotropy;
		this.anisotropyRotation = source.anisotropyRotation;
		this.anisotropyMap = source.anisotropyMap;

		this.clearcoat = source.clearcoat;
		this.clearcoatMap = source.clearcoatMap;
		this.clearcoatRoughness = source.clearcoatRoughness;
		this.clearcoatRoughnessMap = source.clearcoatRoughnessMap;
		this.clearcoatNormalMap = source.clearcoatNormalMap;
		this.clearcoatNormalScale.copy( source.clearcoatNormalScale );

		this.dispersion = source.dispersion;
		this.ior = source.ior;

		this.iridescence = source.iridescence;
		this.iridescenceMap = source.iridescenceMap;
		this.iridescenceIOR = source.iridescenceIOR;
		this.iridescenceThicknessRange = [ ...source.iridescenceThicknessRange ];
		this.iridescenceThicknessMap = source.iridescenceThicknessMap;

		this.retroreflectivity = source.retroreflectivity;

		this.sheen = source.sheen;
		this.sheenColor.copy( source.sheenColor );
		this.sheenColorMap = source.sheenColorMap;
		this.sheenRoughness = source.sheenRoughness;
		this.sheenRoughnessMap = source.sheenRoughnessMap;

		this.transmission = source.transmission;
		this.transmissionMap = source.transmissionMap;

		this.thickness = source.thickness;
		this.thicknessMap = source.thicknessMap;
		this.attenuationDistance = source.attenuationDistance;
		this.attenuationColor.copy( source.attenuationColor );

		this.specularIntensity = source.specularIntensity;
		this.specularIntensityMap = source.specularIntensityMap;
		this.specularColor.copy( source.specularColor );
		this.specularColorMap = source.specularColorMap;

		return this;

	}

}

/**
 * A material for shiny surfaces with specular highlights.
 *
 * The material uses a non-physically based [Blinn-Phong](https://en.wikipedia.org/wiki/Blinn-Phong_shading_model)
 * model for calculating reflectance. Unlike the Lambertian model used in the
 * {@link MeshLambertMaterial} this can simulate shiny surfaces with specular
 * highlights (such as varnished wood). `MeshPhongMaterial` uses per-frag