Artists (Donatello, Brunelleschi, and Da Vinci) during the renaissance discovered the importance of perspective for making images appear realistic. This outdates mathematicians by more than 300 years. Perspective causes objects nearer to the viewer to appear larger than the same object would appear farther away. Another for introducing homogenous coordinates to computer graphics was to accomplish perspective projections using linear operators.

Note how lines known to be parallel in image space appear to converge to a single point when viewed in perspective. This is an important attribute of lines in projective spaces, they always intersect at a point.