Perspective-drawings of impressive accuracy are employed in any number of design and engineering fields. The 3D printer can be used to “print” a gun. Representation is one area where art and science overlap and intersect. The value of an accurate sketch is great in many practical applications.

Backtracking a moment to the simple triangulation model described above:

The dynamic relationship represented in this simple sketch can be additively enhanced to illustrate directional exchange:

Figure 1.2 conveys exchange complexity in the triangulating configuration (art-artist-viewer). For example, we can deduce that art and artist compose a quasi-autonomous relationship. This is true with all parties in this model. However, the sketch does not in its simplicity describe the