Perspective Projection - Transformations and Projections in Computer Graphics - page 79

It is such precisely described methods and techniques that distinguish Alberti from
his predecessors and justify the title “pioneer” or “originator” of perspective.

Exercise 3.4: Given the simple two-point perspective of Figure 3.16, show how the
equally spaced vertical lines (labeled “e”) were constructed.

e e e e e e e e

Figure 3.16: Two-Point Perspective with Equally Spaced Lines.

Leonardo da Vinci, who certainly knew about perspective, developed his own pro-
jection, now known as aerial or atmospheric perspective. This method of adding depth
to a two-dimensional painting is based on the perception that contrasts of color and
shade appear greater in nearby objects than in those far away, and that warm colors
(such as red, orange, and yellow) appear to advance, while cool colors (blue, violet, and
green) appear to recede. Aerial perspective is also used in East Asian art, where zones
of mist are sometimes used to separate near and distant parts of the scene.

3.3 Perspective in Curved Objects

Up until now, we have discussed perspective, converging lines, and vanishing points
in cubes or other objects with large flat surfaces on which it is easy to draw straight
lines. Our accumulated life experience, however, teaches us that even curved objects—
objects without flat parts and with no groups of straight, parallel lines—are seen in
perspective. This section shows how to extend the principles of perspective discussed
earlier to arbitrary surfaces.

(a) (b)

Figure 3.17: Alberti's Method of Perspective Drawing.