relative size: if we assume two objects are similar in size, most people perceive the one that casts the smaller retinal image as farther away.
interposition: if one object partially blocks our view of another, we perceive it as closer. the depth cues provided by interposition make this an impossible scene.
relative height: we perceive objects higher in our field of vision as farther away. becase we assume the lower part of a figure-ground illustration is closer, we perceive it as figure. invert this illustration and the black will become ground, like a night sky.
relative motion. as we move, objects that are actually stable may appear to move. if while riding on a bus you fix your gasze on some point, say a house, the objects beyond the fixation point will appear to move with you. objects in front of the point will appear to move backward. the farther an object is from the fixation point, the faster it will seem to move.
linear perspective: parallel lines appear to meet in the distance. the sharper the angle of convergence, the greater the perceived distance
light and show: shading producing a sense of depth consistent with our assumption that light comes from avove. if you invert this illustration, the hollow will become a hill.