Projections
When all display devices are 2D, you need to devise methods that give a realistic view of a 3D scene onto 2D display. With more and more devices coming in the market with high definition resolution and many advanced features, it becomes even more relevant to find out ways in which you can effectively project your scene on a 2D device. A camera uses a transformation method that captures a 3D scene in a 2D film or screen. The principle that a camera uses is essentially the same as that used in a human eye system. Such transformations that transform 3D scenes to 2D view plane are called projections. More precisely a point P = (x, y, z) in the 3D world is transformed to a point P' = (X',Y',Z') that lies on the projection plane or the view plane as shown in figure.