Aqsis is a cross-platform open source 3D rendering solution adhering to the RenderMan standard, as defined by Pixar Animation Studios for professional production rendering.
Focusing on stability and production usage, features include constructive solid geometry, depth-of-field, extensible shading engine (DSOs), instancing, level-of-detail, motion blur, NURBS, procedural plugins, programmable shading, subdivision surfaces, subpixel displacements and more.
Blender integration is handled by the MOSAIC plugin, which allows rendering to all popular RenderMan renderers.
Mitsuba is a research-oriented rendering system in the style of PBRT, from which it derives much inspiration. It is written in portable C++, implements unbiased as well as biased techniques, and contains heavy optimizations targeted towards current CPU architectures.
Mitsuba is extremely modular: it consists of a small set of core libraries and over 100 different plugins that implement functionality ranging from materials and light sources to complete rendering algorithms.
In comparison to other open source renderers, Mitsuba places a strong emphasis on experimental rendering techniques, such as path-based formulations of Metropolis Light Transport and volumetric modeling approaches. Thus, it may be of genuine interest to those who would like to experiment with such techniques that haven't yet found their way into mainstream renderers.
Yafaray is an open source ray tracer, offering Global Illumination and Photon Mapping, for high quality photorealistic rendering.
Yafaray is hosted and maintained independently at www.yafaray.org.
LuxRender is an open-source, free software rendering system for physically correct, unbiased image synthesis.
It supports both unbiased (MLT/(bidir)Path Tracing) and biased techniques (directlighting, photonmapping), physically correct light sources, advanced procedural textures, spectral light calculus, motion blur, lightgroup blending and tight integration with blender.
www.luxrender.net
