As the 3D rendering and animation industry matures, raytracers are becoming increasingly speedy.
So speedy, in fact, that some 3D apps only offer raytracing.
Raytracing does have a drawback, though; it does not calculate any light that may be bouncing between objects.
For instance, a white ball inside a room with multicolored walls.
With even a matte finish, the ball would be showing the results of the brightly colored walls on its surface in real life, but raytracing does not calculate these.
The result is renderings that perhaps do not show the effects of surroundings on an object quite as well as something that uses radiosity.
Radiosity is probably the single most powerful and photorealistic rendering engine available.
Radiosity analyzes a scene and treats every object and surface as a potential light source.
This allows incoming light to bounce off surfaces and change characteristics as it goes.
This detailed manner of handling light makes radiosity a very sophisticated rendering method.
The biggest drawback is that although powerful, calculating all those extra bounces of light is extremely time intensive.
It is not unusual for a radiosity rendering to take from 4 to 100 times the time to render as a raytracing render.
Be selective about radiosity renderings, or if you know that you need an effect that radiosity will provide (e.
g.
, the colored blushes on the side of the ball), consider "faking it" with raytracing.
For instance, the blushes on the side of the ball could be done with colored lights that cast no shadows.
Faking radiosity sometimes takes a little longer, but it usually saves you time over what you would spend waiting for a true radiosity render.