_transferToBackgroundMaterial( options = null ) {

		if( !options ) {

			options = {};

			for ( const component of this._components ) {
				component.output( options );
			}

		}

		Mediator.mediate( this, this._backgroundMaterial, options, this._backgroundMaterialMediation, this._backgroundCustomDepthMaterial );

	}
According to the list of materialProperties
some properties are sent to material
@param {Object} [options=null]
@private