YafaRay Standalone is a free open-source montecarlo raytracing engine. Raytracing is a rendering technique for generating realistic images by tracing the path of light through a 3D scene. YafaRay engine can be used as a Standalone application or in 3D applications like Blender, pCon-planner and Wings 3D.
YafaRay features include Global Illumination to produce realistic renders of 3D scenes. Supported GI algorithms are Pathtracing, Photon Mapping + Final Gather, Stochastic Progressive Photon Mapping and Bidirectional Pathtracing. The illumination system is based mainly on light coming from an emitting sky, taking into account the soft shadows calculations also involved. The illumination can be obtained from simple backgrounds, HDR images and complete SunSky solutions. YafaRay uses photon mapping techniques to produce fast yet accurate caustics effects.
Five shader materials types are implemented in YafaRay, which are ShinyDiffuse, Glossy, CoatedGlossy, Glass and Rough Glass. They are flexible enough and with many parameters available for each of them to produce a wide range of materials, transparent surfaces and reflections. YafaRay support several procedural textures as well. YafaRay implements four camera types to reproduce different optic effects. YafaRay also supports raytraced depth of field (DOF) to focus a part of the scene.
YafaRay's volumetric features provide a simulation of light interacting with particles suspended in a region of space. YafaRay uses a realistic physics-based model to render volumetrics, and provides a basis for creating not just believable beams of light, but also smoke, clouds, fog, and other volumetric effects.