This is a basic mesh raytracer implemented in Java originally with the intent of prototyping algorithms for a more serious raytracer.
The scene is defined by "defaultscene.txt" which consists of a list of .obj files to load (look at the default file)
There are a number of different hotkeys that will alter the display to show diagnostic information, most of them can be viewed through the window that '?' brings up.
Some interesting options: 'o' displays time-per-ray, 'M' toggles multi-threaded rendering, 'n' displays normals, 'B' displays BVH boxes, 'r' enables basic reflections.

Known issues:
The photon-mapped lighting gathers photons in a spherical radius when it should use either a flattened spheroid or a similar cylinder.
There appear to be some flaws with the generated BVHs on the interior of objects