setViewOffset( fullWidth, fullHeight, x, y, width, height ) {

    		this.aspect = fullWidth / fullHeight;

    		if ( this.view === null ) {

    			this.view = {
    				enabled: true,
    				fullWidth: 1,
    				fullHeight: 1,
    				offsetX: 0,
    				offsetY: 0,
    				width: 1,
    				height: 1
    			};

    		}

    		this.view.enabled = true;
    		this.view.fullWidth = fullWidth;
    		this.view.fullHeight = fullHeight;
    		this.view.offsetX = x;
    		this.view.offsetY = y;
    		this.view.width = width;
    		this.view.height = height;

    		this.updateProjectionMatrix();

    	}
Sets an offset in a larger frustum. This is useful for multi-window or
multi-monitor/multi-machine setups.

For example, if you have 3x2 monitors and each monitor is 1920x1080 and
the monitors are in grid like this

  +---+---+---+
  | A | B | C |
  +---+---+---+
  | D | E | F |
  +---+---+---+

then for each monitor you would call it like this

  const w = 1920;
  const h = 1080;
  const fullWidth = w * 3;
  const fullHeight = h * 2;

  --A--
  camera.setViewOffset( fullWidth, fullHeight, w * 0, h * 0, w, h );
  --B--
  camera.setViewOffset( fullWidth, fullHeight, w * 1, h * 0, w, h );
  --C--
  camera.setViewOffset( fullWidth, fullHeight, w * 2, h * 0, w, h );
  --D--
  camera.setViewOffset( fullWidth, fullHeight, w * 0, h * 1, w, h );
  --E--
  camera.setViewOffset( fullWidth, fullHeight, w * 1, h * 1, w, h );
  --F--
  camera.setViewOffset( fullWidth, fullHeight, w * 2, h * 1, w, h );

  Note there is no reason monitors have to be the same size or in a grid.