POV-Team, contact Chris Cason ( spec001 [at] povray [dot] org )
POV-Ray is a ray-tracer. Ray-tracing is a rendering technique that calculates an image of a scene by simulating the way rays of light travel in the real world but it does so backwards. In the real world, rays of light are emitted from a light source and illuminate objects. The light reflects off of the objects or passes through transparent objects. This reflected light hits the human eye or a camera lens. As the vast majority of rays never hit an observer, it would take forever to trace a scene. Thus, ray-tracers like POV-Ray start with their simulated camera and trace rays backwards out into the scene. The user specifies the location of the camera, light sources, and objects as well as the surface textures and their interiors.
For every pixel rays are shot from the camera into the scene to see if it intersects with any of the objects in the scene. Every time an object is hit, the color of the surface at that point is calculated. For this purpose rays are sent to each light source to determine the amount of light coming from it or if the object is in shadow. For reflective or refractive objects more rays are traced in order to determine the contribution of the reflected and refracted light to the final surface color.
Geometry objects are represented in POV-Ray by their mathematical form and a transformation. For example spheres are represented by a radius, planes by a normal vector and distance from the origin and tori by their inner and outer radii. In total POV-Ray supports 30 different geometric objects including blobs, quadrics, spheres, cylinders, polygons, meshes, isosurfaces and constructive solid geometry. Intersections of rays with geometry objects are computed by solving complex mathematical equations directly or by numeric approximation algorithms. All these algorithms are sensitive to floating-point accuracy.
453.povray renders a 1280x1024 pixel anti-aliased image of a chessboard with all the pieces in the starting position. The objects were selected to show the various geometry objects available POV-Ray. The input file also generates a height field out of a simple fractal function. In addition, the input file provides the function for an isosurface object. All objects in the scene have procedural textures that determine their surface texture. Many of these textures make use of a variant of the Perlin noise function. Further, some objects refract light, others are highly reflective and these surface attributes are procedurally defined, too.
The output files are the rendered image and a log containing statistical information about the intersection tests performed and other related information. These statistics are output after every line rendered. Normally POV-Ray would only output these statistics once after rendering the whole image. This modified output is provided only to verify the workload of the benchmark.
mathimf.h included for Intel compiler with the preprocessor define SPEC_CPU_WINDOWS_ICL. All other portability automatically invoked for the Windows operating systems.
Last updated: $Date: 2008-04-12 08:31:17 -0400 (Sat, 12 Apr 2008) $