ed to rendering, it is somewhat limited. Ray tracing models the reflection of light rays from physical objects. This explanation is somewhat simplistic and bears additional exploration.
Embedded within the concept of ray tracing is the subject of radiosity which models an objectÆs emission of light energy to other objects. The radiosity method is based upon the Law of Conservation of Energy for closed systems (Immel and Cohen, 1986), and is defined as the radiation emitted from a surface per unit time per unit area. The value of the energy emitted includes both reflected energy as well as the original emission (Kwok, 1992). For image synthesis, the radiation is in the form of light. Objects in the scene are therefore illuminated not only by direct lighting, but by the light reflecting off of other objects. This bouncing of light off of other objects is referred to a secondary or indirect lighting effect.
The goal, therefore, of the radiosity methodology, is to identify the point of equilibrium (or balance) associated with all of the radiation in the system. When this point of balance is determined, the relative brightness at each point is known and can be properly displayed. Justifiably, no radiation leakage into our outside of the system can be allowed as this would interfere with the process of finding the balance or equilibrium point.
Radiosity-based rendering is considered to be more difficult to implement and perform than that which is encountered in ray tracing. It is because of this that traditional computer science students do not generally have much of an opportunity to study radiosity during their formal education. The process is also somewhat limited in its applicability due to the associated difficulties which are encountered in the preparation process. It also requires substantially more computing resources than what is necessary for applying ray tracing. Ultimately, a hybrid renderer that combines th...