Measurements

In the first project, you didn’t have to worry about measurements unless you weren’t able to scan your carton reference. Even though most of you didn’t overtly take any measurements, your actions caused measurements to be taken. When you scanned the carton, the scanner used a consistent pixel to linear dimension ratio, commonly known as dots per inch, or DPI. By doing this, the exact dimensions of your scanned carton become embedded in the resulting image. If it was scanned at 150 dpi for instance, and one edge was 750 pixels in length, then that edge is 5-in. long (Fig. 3.1).

In some ways, modeling is all about measurements, and without them, there would be no such thing as 3D graphics.

All things in a CG environment rely on measurements for their depiction. Models are constructed entirely of measurements of the distance from a threedimensional station point to another three-dimensional location, or vertex. Textures are located on objects based on two-dimensional measurements within X, Y object space. Lights are located based on measurements; their intensity is a measurement, as are all of their other variables.