Indirect illumination
Global illumination
Indirect illumination and global illumination are similar. Both effects are the result of light hitting objects in the scene, then bouncing off those objects to illuminate other objects in the scene. With both illumination types, the bounced light can reach areas that direct light from the light sources could not otherwise reach.
Indirect illumination is the result of light transmitted from a source onto objects in the scene that are then diffusely spread from one object to another. Objects send out sampling rays from each pixel in the image and gather the color information on what the rays hit. More rays result in more realistic color bleeding and slower performance.
Global illumination is the result of photons being emitted into the scene by each light source. As the photons bounce around the scene and hit an object, they store the color information. The distance that the photons travel and the strength of the effect is determined by the photon energy. More photons result in more realistic effects and slower performance.
Note the following images. One shows the effect of indirect illumination, and the other shows the effect of global illumination. The effects produce similar results. It is recommended that you vary the intensity of lights, the energy and amount of photons, and the diffuse property of the materials to find the combination that produces the best results for your scene.
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Indirect illumination |
Global illumination |
Back to Illumination Options.