A 640 x 640 picture which shows most of the features of the ray_tracer.
Rendering time is 19 hrs with adaptive random sampling comparing to 4.5 hrs
without using random sampling.

The scene is composed of more than 40 object primitives, mainly spheres
ellipsoids, and cylinders and is exposed to 3 different light sources

Both the face and the belt are constructed by CSG operation.  The face is
the difference of a sphere and cube, while the belt is difference of two
cubes.

The left bomb on the floor is a reflective one while the one on the right
is transparent located in front of the feet.

Texture mapping is applied to the floor and the wall. 

Kwok-Chung Wong