ABSTRACT
This chapter covers the fundamentals of geometric coordinates and coordinate systems. It discusses tris or quads, also known as triangles or quadrilaterals, which are used in graphics modeling. The notion of planarity will be used to help students understand the rationale behind the use of triangles by three-dimensional (3D) engines during the rendering process. A coordinate or coordinates is/are the numerical representation(s) of the location or position of something. One commonly used coordinate system is the Cartesian coordinate system. The Cartesian coordinate system is just one way to represent locations in space. There are different kinds of coordinate systems. Consider the rectangular area shown in the two-dimensional Cartesian coordinate system. Modeling software need to determine the orientation of a polygon’s face to estimate how the surface will appear or will be viewed by the user. The structure or the order in which the vertices are organized around a polygon helps estimate the direction the polygon faces.
