Picogen is a program to create, design, and render artificial 3D terrain scenes. It is currently not very nice to non-programming-end-users, as the heightmap definition is a program with a LISP-like syntax. It aims to be similar to the Terragen program and provide a free and unrestricted alternative to it.
In p, a bunch of particles interact with each other according to this simple rule: every particle moves towards, away, or watches other particles. When the program starts, each particle chooses a random color, position, and the particles with which it will interact. As the program runs, some particles join together to form a train and journey together thereafter. Some orbit each other. Some collapse into each other. Some form swarms that split and join. One cannot predict when or where or how many of these behaviors will emerge, but they usually do.
The PVM patch for POV-Ray gives POV the ability to distribute a rendering across multiple heterogeneous systems. Using the PVM code, there is one master and many slave tasks. The master has the responsibility of dividing the image up into small blocks, which are assigned to the slaves. When the slaves have finished rendering the blocks, they are sent back to the master, which combines them to form the final image.
Rearview is a three dimensional computer graphics engine which fits both human perception and the shape of the real world better than common polygon renderers do. It is not meant to be a very sharp-shaped, high-contrast engine. Rearview's strength are grown things, dirty things, and bumpy things, like smooth hills and old walls. To achieve this, rearview uses a raytracing algorithm to visualise voxels stored in an octree.