Allow to do easy set dressing TIP:     - *Click and drag on the objects in the scene to place, scale and rotate them.* - Scrollwheel switches between the input objects to be placed.     * CTRL+LMB Drag allows for tweaking of previously placed objects.     * CTRL+SHIFT+LMB Drag allows changing scale and rotation of already placed objects.     * CTRL+MMB Click removes previously placed objects.     * RMB Click exposes a lot of placement controls. * TIP:     * It is highly recommended you plug in packed primitives as the geometry to place.