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.

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.



LuxRender is a 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.



Yafaray is a ray tracer, offering Global Illumination and Photon Mapping, for high quality photorealistic rendering.



Aqsis is a cross-platform 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.



POV-Ray, is the oldest free and open-source 3D renderer. It generates images from a text-based scene description language. It supports mathematically defined primitives as well as their polygonal counterparts; A Turing-complete scene description language (SDL) that supports macros and loops; Subsurface Scattering (sss) and translucency; Atmospheric effects such as fog and media (smoke, clouds); photon mapping; Pause and restart a render after shutdown; Real Time Rendering mode, etc.

Read more in Blender’s exporter wiki.