Lining Up: 2D Lines
“Real” objects are three-dimensional, or 3D. So why should we consider 2D objects, such as the 2D lines in this chapter? Because they really are the building blocks for geometric constructions and play a key role in many applications. We’ll look at various representations for lines, where each is suited for particular applications. Once we can represent a line, we can perform intersections and determine distances from a line.
Figure 3.1 shows how interesting playing with lines can be. Two sets of parallel lines are overlaid and the resulting interference pattern is called a Moiré pattern. Such patterns are used in optics for checking the properties of lenses.