Instancing

Quite some time ago, I added instancing to my raytracer, but never used it for the images I've posted here:

Click on the image for a larger version.

There is a single centered at 0,0,0 and then 10 instances are created, rotated and translated into place.
I've switched to a yellow specular reflection and I'm not sure if I like it.

Notice the lack of shadows. Argh. Those need to be in place before the final animation.