the process of representing threedimensional images on a two-dimensional computer screen. This ability is especially important in CAD and in games. For example, imagine that you are designing a house, and your computer program lets you simulate walking through the different rooms. The computer needs to keep track of three-dimensional coordinates of the points of the house, and it needs to know which points are connected with lines, which planes should be filled in (as in a wall) or left open (as in a door). To allow the user to view the image from different points, the computer needs to be able to translate or rotate the points as directed. Particularly in a game setting, the computer needs to redraw the entire screen very quickly to maintain the illusion of rapid motion.
