Creating a three-dimensional (3D) model of an object in a computer involves a coordinate system and algebraic calculations necessary to manipulate (change shape, scale, orientation, and location) the modeled object. Every spatial object, such as a 3D model of a house, is based on coordinates referenced to a specific coordinate system. The most popular system of coordinates used in almost every 3D modeling software is the Cartesian coordinate system, described by three coordinates, x, y, and z, corresponding to the three dimensions of space. In the Cartesian coordinate system, all three axes are perpendicular to each other, and the system is defined by its origin (0, 0, 0) and the orientation of the x, y, and z axes. The simplest way of referencing one object ...