vsmPass( renderer ) {

		const { shadow } = this;

		const depth = this.shadowMap.depth;
		this.vsmShadowMapVertical.setSize( shadow.mapSize.width, shadow.mapSize.height, depth );
		this.vsmShadowMapHorizontal.setSize( shadow.mapSize.width, shadow.mapSize.height, depth );

		renderer.setRenderTarget( this.vsmShadowMapVertical );
		_quadMesh.material = this.vsmMaterialVertical;
		_quadMesh.render( renderer );

		renderer.setRenderTarget( this.vsmShadowMapHorizontal );
		_quadMesh.material = this.vsmMaterialHorizontal;
		_quadMesh.render( renderer );

	}
For VSM additional render passes are required.

@param {Renderer} renderer - A reference to the current renderer.