Cues Supporting 3-D Inference

2-D cues supporting 3-D representation:

• Linear perspective: converging lines in 2-D convey parallel lines and depth in 3-D
• Gradient of size: elements of uniform texture decrease in size as they approach the horizon
• Aerial perspective: objects in the far distance appear lighter and blue
• Binocular parallax: each eye receives a slightly different image allowing the brain to make inferences about distance;
• Motion parallax: movement on the part of the observer changes images on each retina;

Cues support inference to 3-D interpretation but inference is unconscious.

• experiments suggest we have no notion of the cues are brains are using;
• cues can be removed without sacrificing judgment about relative distances and placements of objects.