4. The cube is in many ways the most important single shape you will study
in your art career. Both simple and complex structural development can be
illustrated by this one geometric form.
Its importance will become
increasingly evident as you work with three-dimensional forms and
measurement, especially when you draw objects in perspective.
preceding text segment pointed out, in order to solve many practical
problems in perspective, you will use the cube or some portion of it as a
medium of measurement. This may be a tedious business because you may make
several sketches before you get an acceptable drawing. But it is time and
effort well spent. Some artists who make cubes too wide or too narrow have
never really learned what a square, hence a cube, looks like in perspective.
a. Although the cube is perhaps the most important shape, the circle is
the guide for drawing all two-dimensional curves, ellipses and ovals in
perspective. Even so, its basis is the square, or one surface of the cube.
The square is used because there are no direct measurements on a curve in
Vanishing points are determined from the square, and
proportions of the curve can easily be seen within the square. Figure 3-5
shows the proper layout of a circle in perspective. The first step in the
instrument layout is to draw a circle with the desired dimensions. Second,
draw the square around the circle and add the diagonal and centerlines as
shown in step 2.
This will give you eight checkpoints for drawing the
circle in perspective. Next, draw the perspective lines back to the desired
vanishing point to establish the square in perspective.