Hughes/Computer Graphics, 3/E

Chapter 10. Transformations in Two Dimensions

10.1. Introduction

As you saw in Chapters 2 and 6, when we think about taking an object for which we have a geometric model and putting it in a scene, we typically need to do three things: Move the object to some location, scale it up or down so that it fits well with the other objects in the scene, and rotate it until it has the right orientation. These operations—translation, scaling, and rotation—are part of every graphics system. Both scaling and rotation are linear transformations on the coordinates of the object’s points. Recall that a linear transformation,

is one for which T(v + αw) = T(v