Before revision: Controversy 2D symmetry was once thought to be able to facilitate 3D object recognition under accidental viewpoints.
After revision: upright=.8|The Ambassadors – Hans Holbein the Youngerupright=.8|The Ambassador's Skull: detail when viewed from the accidental viewpoint (from The Ambassadors – Hans Holbein the Younger)Controversy 2D symmetry was once thought to be able to facilitate 3D object recognition under accidental viewpoints.