Viewing Systems |
An image of a physical object can be formed using a camera; the light reflected by the object is used to expose the film. The body of the camera is used to control the directions that the light which strikes the film is allowed to come from.
An image of a synthetic object can be created several ways. One way that is analogous to the camera and the formation of the physical image is ray tracing or ray casting, a method where rays are projected from the eye point into the scene to be displayed. Reflections are calculated, and if the ray ends up at a light source then it is used to contribute to the final image.