Global Illumination vs. Radiosity ???

Is Global Illumination (GI) better than Radiosity?

No! Why? Because radiosity is a SUBSET of GI.
They are not two different methods for calculating the light-distribution in a scene.

GI is an opposite of 'local illumination' or 'direct illumination', which
shaders like phong etc use.

Radiosity (Wavelet Radiosity, Hierarchical Radiosity), Photon Mapping and Monte Carlo, are different techniques for calculating the GI of a 3d scene.

GI is a meta-term for radiosity, monte carlo algorith etc.



(1) Radiosity

(2) GI Methods discussion

(3) Overview Radiosity

(4) Direct Illumination (Shading)

(5) Very good explaination of Radiosity and GI. Compares a bit Radiosity with Monte Carlo

(6) Few slides about GI

(7) Bref history of radiosity

(8) GI: Wavelet and Hirachical Radiosity, Radiance

(9) Monte Carlo GI

(10) GI links on CGarchitect



(prefix); concerning waves of force; e.g. light, sound or radio waves
[source: Longman: dictionary of contemporay english]

radiosity (source: link nr. 1)
- integral of emitted radiance plus reflected radiance over a
hemisphere. units: [power/area]
- radiosity is outgoing power per unit area due to emission or
reflection over a hemisphere of directions.

Thus, “radiosity” is both a unit of light and an algorithm.