Computer rendering

In 3D computer graphics, rendering is the process of drawing a 2D image, based upon a scene description (which may include geometry and material properties). It is typically a slow, computationally intensive process. The term is by analogy with an "artist's rendering" of a scene.

When the pre-image (a wireframe sketch usually) is complete, rendering is used, which adds in textures, lights, bump mapping, and relative position to other objects. The result is a completed image the consumer or intended viewer sees.

For animations, several images (frames) must be rendered, and stitched together in a program capable of making an animation of this sort. Most 3-D image editing programs can do this.

There are a number of different phenomena that need to be simulated when rendering a scene:

• [diffuse reflection]?
• [specular reflection]?
• refraction
• global illumination
• depth of field
• [motion blur]?
• diffraction

All of these effects can be summed up in a single 'rendering equation' that contains very complex constants that in effect encode the scene.

All 3-D rendering software and hardware produces an approximation to a solution of the idealised rendering equation.

Methods of rendering include:

• the [painter's algorithm]?
• Ray tracing
• Global illumination
• Radiosity
• [Scanline algorithms]?

Rendering often takes place on a render farm.

The current state of the art in 3-D image description is the RenderMan? [scene description language]? designed at PIXAR?. (compare with simpler APIs such as OpenGL and DirectX)

Rendering software includes:

• PRman?
• POV-ray?
• [Mental Ray]?

Fill in research - image based rendering, non photorealism, hardware assisted, etc.

External links:

• http://www.povray.org/