To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie S5. Variants of the surfaces shown in Movie S1 with superimposed specular reflections appropriate for each 3D shape interpretation. Note that the snake shape still appears more translucent than the ribbon when specular highlights are added. Perception and misperception of surface opacity Phillip J. Marlow, Juno Kim, and Barton L. Anderson PNAS. 2017. 114:13840-13845 DOI: 10.1073/pnas.1711416115 Download Original Video Browse All Videos »