What is Ray Casting?
Ray casting is a process that is helpful in identifying and solving a wide range of problems associated with graphics. Sometimes confused with the process of ray tracing, ray casting does perform some of the same functions and usually is able to move with greater speed than current raytracing protocols. The development of the first ray casting algorithm is usually traced back to 1968 and the work of Arthur Appel. Somewhat more focused in scope than ray tracing, ray casting makes it possible to take 3D images and render them effectively to two-dimensional screens. This is accomplished by tracking the rays of light that trace a direct path from the eye to some source of light. However, ray casting discounts the influence of any element that may intersect that path between the eye and the light source, although the effect of these elements at the point of termination does come into play. Typical influences would be refraction, reflection and shadowing. One of the easiest ways to understan
Ray casting is a method for calculating Field of Vision where rays are traced from the center of a source square to a select number of destination squares. Squares are marked as visible as the rays pass through them, and walls will block the rays. There are a few ways to decide where rays are to be cast: • Every potential destination — This method is very slow, but results in a crude approximation of Shadow casting. • Every square along the perimeter of the area being checked for Field of Vision — This is faster, but causes an increasing number of artifacts as the radius increases. • A fixed number of rays as regular intervals — Provides a tweakable knob that trades off between accuracy and speed.
