render( renderer, writeBuffer, readBuffer /*, deltaTime, maskActive */ ) {

		const context = renderer.getContext();
		const state = renderer.state;

		// don't update color or depth

		state.buffers.color.setMask( false );
		state.buffers.depth.setMask( false );

		// lock buffers

		state.buffers.color.setLocked( true );
		state.buffers.depth.setLocked( true );

		// set up stencil

		let writeValue, clearValue;

		if ( this.inverse ) {

			writeValue = 0;
			clearValue = 1;

		} else {

			writeValue = 1;
			clearValue = 0;

		}

		state.buffers.stencil.setTest( true );
		state.buffers.stencil.setOp( context.REPLACE, context.REPLACE, context.REPLACE );
		state.buffers.stencil.setFunc( context.ALWAYS, writeValue, 0xffffffff );
		state.buffers.stencil.setClear( clearValue );
		state.buffers.stencil.setLocked( true );

		// draw into the stencil buffer

		renderer.setRenderTarget( readBuffer );
		if ( this.clear ) renderer.clear();
		renderer.render( this.scene, this.camera );

		renderer.setRenderTarget( writeBuffer );
		if ( this.clear ) renderer.clear();
		renderer.render( this.scene, this.camera );

		// unlock color and depth buffer and make them writable for subsequent rendering/clearing

		state.buffers.color.setLocked( false );
		state.buffers.depth.setLocked( false );

		state.buffers.color.setMask( true );
		state.buffers.depth.setMask( true );

		// only render where stencil is set to 1

		state.buffers.stencil.setLocked( false );
		state.buffers.stencil.setFunc( context.EQUAL, 1, 0xffffffff ); // draw if == 1
		state.buffers.stencil.setOp( context.KEEP, context.KEEP, context.KEEP );
		state.buffers.stencil.setLocked( true );

	}
Performs a mask pass with the configured scene and camera.

@param {WebGLRenderer} renderer - The renderer.
@param {WebGLRenderTarget} writeBuffer - The write buffer. This buffer is intended as the rendering
destination for the pass.
@param {WebGLRenderTarget} readBuffer - The read buffer. The pass can access the result from the
previous pass from this buffer.
@param {number} deltaTime - The delta time in seconds.
@param {boolean} maskActive - Whether masking is active or not.