p400fig11.40 When planar 2D parallelograms are justaposed, the resultant forms generate 3D percepts that are sensitive to the configuration of angles and edges in the fugure.  See the text for why.<BR>||  3D representation of 2D images,  Monocular cues (eg angles) can interact together to yield 3D interpretation.  Monocular cues by themselves are often ambiguous.  Same angles and shapes, different surface slants.  How do these ambiguous 2D shapes contextually define a 3D object form?