Lighting Design and Simulation Knowledgebase
(Term of computer graphics)
A method of computer graphics, normal used to create synthetic images of imaginary scenes in space.
There are two variants of raytracing:
Forward Raytracing
In this case, the program simulates rays of
light (or other spectra) that emanate from
a light source, and determines where they end
up when following a number of reflecion on scene
surfaces. This method is normally used in the
design of luminaire reflectors and other optical
equipment.
Backwards Raytracing
Here the program starts with scene, and casts
rays into different directions, until they hit a
surface in the scene. At this point, it tries
to find out what amount of light is available
to illuminate this surface. This can happen
with the help of an ambient term, which represents
an (unrealistic) global brightness of the scene, by
determining the distance to one or several light
sources, or recursively by sending more rays
into the scene from that point on.
A combination of the last two methods, called
distributed raytracing,
is the most interesting one for our purposes.
Distributed Raytracing
Stochastic Raytracing
This is a very powerful approach
for simulating the diffuse light distribution and
reflection in three dimensional environments
(a solution to the "global illumination model") and is used
in the Radiance software.
Distributed raytracing can simulate scenes of extreme complexity quite effectively, while for scenes with very high numbers of light sources the radiosity approach often has some advantages.
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References: |
radiosity method Radiance software |
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| English | German | |
| raytracing | Das Raytracing | |
| forward raytracing | Das Vorwärtsraytracing | |
| backwards raytracing | Das Rückwärtsraytracing | |
| distributed raytracing | Das diffuse Raytracing | |
| stochastic raytracing | Das stochastische Raytracing |
