Distributed ray tracing

Distributed ray tracing

Distributed ray tracing, also called distribution ray tracing and stochastic ray tracing, is a refinement of ray tracing that allows for the rendering of "soft" phenomena.

Conventional ray tracing uses single rays to sample many different domains. For example, when the color of an object is calculated, ray tracing might send a single ray to each light source in the scene. This leads to sharp shadows, since there is no way for a light source to be partially occluded (another way of saying this is that all lights are point sources and have zero area). Conventional ray tracing also typically spawns one reflection ray and one transmission ray per intersection. As a result, reflected and transmitted images are perfectly (and unrealistically) sharp.

Distributed ray tracing removes these restrictions by averaging multiple rays distributed over an interval. For example, soft shadows can be rendered by distributing shadow rays over the light source area. Blurry reflections and transmissions can be rendered by distributing reflection and transmission rays over a solid angle about the "true" reflection or transmission direction. Adding "soft" phenomena to ray-traced images in this way can improve realism immensely, since the sharp phenomena rendered by conventional ray tracing are almost never seen in reality.[citation needed]

More advanced effects are also possible using the same framework. For instance, depth of field can be achieved by distributing ray origins over the lens area. In an animated scene, motion blur can be simulated by distributing rays in time. Distributing rays in the spectrum allows for the rendering of dispersion effects, such as rainbows and prisms.

Mathematically, in order to evaluate the rendering equation, one must evaluate several integrals. Conventional ray tracing estimates these integrals by sampling the value of the integrand at a single point in the domain, which is clearly a very bad approximation. Distributed ray tracing samples the integrand at many randomly chosen points and averages the results to obtain a better approximation. It is essentially an application of the Monte Carlo method to 3D computer graphics, and for this reason is also called stochastic ray tracing.

The term distributed ray tracing also sometimes refers to the application of distributed computing techniques to ray tracing, but because of ambiguity this is more properly called parallel ray tracing (in reference to parallel computing).

See also

External links


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Distributed ray tracing — Mit diffusem Raytracing gerendertes Bild. Der Algorithmus erzeugt weiche Schatten, kann aber nicht den Lichtaustausch zwischen diffusen Flächen berechnen. Das Bild wirkt dadurch zu dunkel. Diffuses Raytracing, auch stochastisches Raytracing oder… …   Deutsch Wikipedia

  • Ray Tracing — Raytracing (dt. Strahlverfolgung[1] oder Strahlenverfolgung[2], in englischer Schreibweise meist ray tracing, seltener ray shooting) ist ein auf der Aussendung von Strahlen basierender Algorithmus zur Verdeckungsberechnung, also zur Ermittlung… …   Deutsch Wikipedia

  • Ray tracing — Raytracing (dt. Strahlverfolgung[1] oder Strahlenverfolgung[2], in englischer Schreibweise meist ray tracing, seltener ray shooting) ist ein auf der Aussendung von Strahlen basierender Algorithmus zur Verdeckungsberechnung, also zur Ermittlung… …   Deutsch Wikipedia

  • Ray tracing (graphics) — In computer graphics, ray tracing is a technique for generating an image by tracing the path of light through pixels in an image plane. The technique is capable of producing a very high degree of photorealism; usually higher than that of typical… …   Wikipedia

  • Forward Ray Tracing — Raytracing (dt. Strahlverfolgung[1] oder Strahlenverfolgung[2], in englischer Schreibweise meist ray tracing, seltener ray shooting) ist ein auf der Aussendung von Strahlen basierender Algorithmus zur Verdeckungsberechnung, also zur Ermittlung… …   Deutsch Wikipedia

  • Beam tracing — is a derivative of the ray tracing algorithm that replaces rays, which have no thickness, with beams. Beams are shaped like unbounded pyramids, with (possibly complex) polygonal cross sections. Beam tracing was first proposed by Paul Heckbert and …   Wikipedia

  • Cone tracing — is a derivative of the ray tracing algorithm that replaces rays, which have no thickness, with cones. Cone tracing is related to beam tracing, but uses circular rather than polygonal cross sections. Cone tracing solves certain problems related to …   Wikipedia

  • POV-Ray — Infobox Software name = POV Ray caption = developer = The POV Team latest release version = 3.6 latest release date = October 03, 2004 latest preview version = 3.7.beta.29b latest preview date = october 03, 2008 operating system = Cross platform… …   Wikipedia

  • Manta Interactive Ray Tracer — Manta is a highly portable interactive ray tracing (graphics) environment designed to be used on both workstations and super computers and is distributed under the MIT license. It was originally developed at the University of Utah. References… …   Wikipedia

  • Backward Raytracing — Raytracing (dt. Strahlverfolgung[1] oder Strahlenverfolgung[2], in englischer Schreibweise meist ray tracing, seltener ray shooting) ist ein auf der Aussendung von Strahlen basierender Algorithmus zur Verdeckungsberechnung, also zur Ermittlung… …   Deutsch Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”