English: A 3D rendered image using
path tracing, rendered by
Blender's Cycles renderer.
Lower quality settings have been used in order to highlight the potential weaknesses of path tracing (the Cycles renderer is capable of much higher quality images). The scene uses very simple lighting, and uniform background colors, to make it easier to interpret differences in global illumination.
All materials in the scene are rendered realistically, but there is significant noise, because only 16 light paths were sampled per pixel. Most of the noise occurs in regions illuminated by light passing through the transparent cow, or reflecting from the mirrored cow, and being scattered to different parts of the scene. This type of illumination produces bright spots, sometimes with complex shapes, called
caustics and is something that path tracing has difficulty capturing. Diffuse indirect illumination is handled well by path tracing. The low resolution of the mesh causes some artifacts (particularly along the shadow
terminator), because path tracing needs to be able to intersect rays with accurate geometry.