Editing POV-Ray (section)

===Primitives===
[[File:Venn 0000 0001 0001 0110.png|thumb|Rendering of the [[Venn diagram]] of four spheres created with [[constructive solid geometry]], or CSG. The source is [[commons:File:Venn 0000 0001 0001 0110.png#POV-Ray source|on the description page]] of the image.]]
[[Image:PNG transparency demonstration 1.png|thumb|Some colored [[dice]] rendered in POV-Ray. [[Constructive solid geometry|CSG]], [[refraction]] and [[focal blur]] are demonstrated.]]
POV-Ray, in addition to standard [[3d geometry|3D geometric]] shapes like [[torus|tori]], [[sphere]]s, and [[heightfield]]s, supports mathematically defined ''[[Primitives (computer graphics)|primitives]]'' such as the [[isosurface]] (a finite approximation of an arbitrary function), the [[polynomial]] primitive (an [[Infinity|infinite]] object defined by a [[Degree of a polynomial|15th order or lower polynomial]]), the [[julia set|julia fractal]] (a 3-dimensional slice of a [[Four-dimensional space|4-dimensional]] fractal), the [[superellipse|superquadratic ellipsoid]] (an intermediate between a sphere and a cube), and the [[parametric feature based modeler|parametric]] primitive (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 computer programs that include 3D models, which typically use [[triangle]] [[polygon mesh|mesh]]es to compose all the objects in a scene.

This fact provides POV-Ray with several advantages and disadvantages over other rendering and 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, e.g., 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 connected polygons (usually [[UV sphere|quads]] or [[Icosphere|triangles]]).

On the other hand, script-based primitive modeling is not always a practical method to create certain objects, such as realistic characters or complex man-made artifacts like cars. Those objects can be created first in mesh-based modeling applications such as [[Wings 3D]] and [[Blender (software)|Blender]], and then they can be converted to POV-Ray's own mesh format.