name = POV-Ray
developer = The POV-Team
latest_release_version = 3.6
October 03, 2004
latest_preview_version = 3.7.beta.29b
october 03, 2008
genre = Ray tracer
license = POV-Ray License
website = [http://www.povray.org/ www.povray.org]
The Persistence of Vision Raytracer, or POV-Ray, is a
ray tracingprogram available for a variety of computer platforms. It was originally based on DKBTrace, written by David Kirk Buckand Aaron A. Collins. There are also influences from the earlier Polyray raytracer contributed by its author Alexander Enzmann. POV-Ray is freewarewith the source code available.
Some time in the 1980s,
David Kirk Buckdownloaded the source codefor a Unixraytracer to his Amiga. Interested, he played with it for a while, eventually deciding to write his own raytracer, named DKBTraceafter his initials. He posted it to his bulletin board system, thinking others might be interested in it. In 1987, Aaron A. Collinsdownloaded DKBTrace and began working on an x86-based port of it. He and David Buck collaborated to add several more features. When the program proved to be more popular than anticipated, they could not keep up with demand for more features. Thus, in July 1991 David turned over the project to a team of programmers. At the same time, he felt that it was inappropriate to use his initials on a program he no longer maintained. The name "STAR" (Software Taskforce on Animation and Rendering) was considered, but eventually the name became the "Persistence of Vision Raytracer", or "POV-Ray" for short. [ [http://www.povray.org/documentation/view/3.6.0/7/ POV-Ray: Documentation: 1.1.5 The Early History of POV-Ray ] ]
POV-Ray was the first ray tracer to render an image in orbit, rendered by
Mark Shuttleworthinside the International Space Station. [ [http://www.oyonale.com/iss.php Reach for the stars ] ]
Features of the application and a summary of its history are discussed in an interview with David Kirk Buck and Chris Cason on episode 24 of
FLOSS Weekly[ [http://twit.tv/floss24 The TWiT Netcast Network with Leo Laporte ] ] .
POV-Ray has matured substantially since it was created. Recent versions of the software include the following features:
* A Turing-complete scene description language (SDL) that supports macros and loops. [See the SCC3 page at http://local.wasp.uwa.edu.au/~pbourke/modelling_rendering/scc3/final/ for an example of complete POV-Ray images made with no more than 256 bytes of SDL, several of which use recursion and macros to compress the code]
* Library of ready-made scenes, textures, and objects
* Support for a number of
geometric primitives and constructive solid geometry
* Several kinds of
Atmospheric effects such as fogand media ( smoke, clouds)
refractions, and light caustics using photon mapping
* Surface patterns such as
wrinkles, bumps, and ripples, for use in procedural texturesand bump mapping
* Image format support for
textures and rendered output, including TGA, PNG, JPEG(only input) among others
One of POV-Ray's main attractions is its large collection of third party support. A large number of tools, textures, models, scenes, and tutorials can be found on the web. It is also a useful reference for those wanting to learn how
ray tracingand related geometry and graphics algorithms work.
The current official version of POV-Ray is 3.6. Some of the main features of this release:
UV-mappingto more primitives.
* Adds 16 and 32 bit integer data to density file.
bugfixes and speed-ups.
* Improved 64 bit
Beta-testing of version 3.7 is underway as of July 2008. The main improvement over 3.6 will be SMP support to allow the renderer to take advantage of multiple processors. Additionally, support has been added for HDRI, including the
OpenEXRand Radiance file formats, and improved bounding using BSP trees.
In July 2006,
Intelcorporation started using the beta version to demonstrate their new dual-core Conroe processor due to the efficiency of the 3.7 beta's SMP implementation. [http://www.intel.com/performance/desktop/extreme/high_end_rendering.htm]
POV-Ray, in addition to standard
geometricshapes like tori, spheres and heightfields, supports mathematically defined primitives such as the isosurface(a finite approximation of an arbitrary function), the polynomialprimitive (an infinite object defined by a 15th order or lower polynomial), the julia fractal (a 3-dimensional slice of a 4-dimensional fractal), the superquadratic ellipsoid (intermediate between a sphere and a cube), and the parametricprimitive (using equations that represent its surface, rather than its interior).
POV-Ray internally represents objects using their mathematical definitions; all POV-Ray primitive objects can be described by mathematical functions. This is different from many 3D computer modeling packages, which typically use triangle meshes to compose all objects.
This fact provides POV-Ray with several advantages and disadvantages over other rendering / modeling systems. POV-Ray primitives are more accurate than their polygonal counterparts. Objects that can be described in terms of spheres, planar surfaces, cylinders, tori and the like are perfectly smooth and mathematically accurate in POV-Ray renderings, whereas polygonal artifacts may be visible in mesh-based modeling software. POV-Ray primitives are also simpler to define than most of their polygonal counterparts. In POV-Ray, a sphere is described simply by its center and radius; in a mesh-based environment, a sphere must be described by a multitude of small polygons.
On the other hand, primitive-, script-based modeling is not always a practical method to create objects such as realistic characters or complex man-made artifacts like cars. Those objects have to be created in mesh-based modeling applications such as
Wings 3Dor Blender and then converted to POV-Ray's own mesh format.
Examples of the Scene Description Language
The following is an example of the scene description language used by POV-Ray to describe a scene to render. It demonstrates use of the camera, lights, a simple box shape and the transforming effects of scaling, rotation and translation.
The following script fragment shows the use of variable declaration, assignment, comparison and the while loop construct:
Development and maintenance
Official modifications to the POV-Ray source tree are done and/or approved by the POV-Team. Most patch submission and/or bug reporting is done in the POV-Ray newsgroups on the povray.org news server. Since POV-Ray's source is available there are unofficial forks and patched versions of POV-Ray available from third parties; however, these are not officially supported by the POV-Team.
Official POV-Ray versions currently do not support
shaderplug-ins [for such an implementation, see e.g. http://www.aetec.ee/fv/vkhomep.nsf/pages/povman2] . Some features, like radiosityand splines are still in development and may be subject to syntactical change.
POV-Ray is distributed in compiled format for
Macintosh, Windows and Linux.Support for Intel Macs is not available in the Macintoshversion, but since Mac OSis a version of Unixthe Linux version can be compiled on it. POV-Ray also could be ported to any platform which has compatible C++compiler.
People with Intel Macs can use
MegaPOVthough, as that is compiled as Universal Binary.
POV-Ray is distributed under the POV-Ray License, which permits free distribution of the program source code and binaries, but restricts commercial distribution and the creation of derivative works other than fully functional versions of POV-Ray.
source codeis available for modification, due to specific restrictions, it is not open sourceaccording to the OSI definition of the term. One of the reasons that POV-Ray is not licensed under the free software GNU General Public License(GPL), or other open source licenses, is that POV-Ray was developed before the GPL-style licenses became widely used; the developers wrote their own license for the release of POV-Ray, and contributors to the software have worked under the assumption that their contributions would be licensed under the POV-Ray License.
The whereabouts of some of the contributors to the
source codeare unknown, and therefore the license cannot be changed, since the permission of all contributors would be required.
A complete rewrite of POV-Ray ("POV-Ray 4.0") is currently under discussion, which would use a more liberal license, most likely GPL v3 [cite web
title=Re: Status of Moray? ("The answer is about POVRay")
quote="Now that process has been completed, as a group we feel the GPL3 is the way to go and have informally decided that 4.0 will be GPL3-licensed."
YafRay(Yet Another Free Raytracer)
KerkytheaFree ray tracing program with enhanced Sketchup compatibility
Sunflowan open source rendering system for photo-realistic image synthesis written in Java
Blender (software)a free and open-source software program for 3D modeling, animation, and rendering
* [http://www.povray.org/ POV-Ray homepage]
* [http://dmoz.org/Computers/Software/Graphics/3D/Animation_and_Design_Tools/POV-Ray/ Category at ODP]
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Look at other dictionaries:
POV-Ray — Une animation réalisée avec POV Ray … Wikipédia en Français
POV-ray — Une animation réalisée avec POV Ray … Wikipédia en Français
Pov-Ray — Une animation réalisée avec POV Ray … Wikipédia en Français
Pov-ray — Une animation réalisée avec POV Ray … Wikipédia en Français
POV-Ray — Der Utah Teapot gerendert in POV Ray unter Verwendung von Schattenwurf, specular highlighting, farbigem Licht und bump mapping Basisdaten Aktuelle Version … Deutsch Wikipedia
POV-Ray — Imagen realista realizada con POV Ray Desarrollador The POV Team www.povray.org … Wikipedia Español
POV-Ray — POV Ray … Википедия
Pov-ray — Der Utah Teapot gerendert in POV Ray unter Verwendung von Schattenwurf, specular highlighting, farbigem Licht und bump mapping Basisdaten Aktuelle Version: 3.6.1 (4. August … Deutsch Wikipedia
POV-Ray — Persistent Of Vision Raytracer (korrekte Schreibweise zum) Freeware Reytracer für mehrere Rechnerarchitekturen (siehe http://www.povray.org/) … Acronyms
POV-Ray — Persistent Of Vision Raytracer (korrekte Schreibweise zum) Freeware Reytracer für mehrere Rechnerarchitekturen (siehe http://www.povray.org/) … Acronyms von A bis Z