Camera - polygon rendering and ray tracing methods

Camera presents "viewpoint" or "eye" of observer. In order to explain the fundamental working of camera we can consider this as the working of "pin-hole camera" as demonstrated in the below figure:

 Figure

The hole or say "aperture" should be so small that it should prevent light from saturating and hence overexposing the film. It permits only a little bit of light in the box at one time. Such kind of camera, although simple, is quite effectual. It works since light from a specified position on the object may come from only one way and strike only one position upon the film. If the hole were any superior, the image would turn into blurrier as a outcome of the increased amount of light hitting every spot on the film.

Figure

In the ray tracing, the camera is much like same this, in that it decides where on the "film" or say in the case of ray tracing, the computer screen the light rays hit such a clear realistic rendered image is accessible. So as to have a better understanding of the topic here we are going to discuss the concept of ray casting.