Another day at the beamline...

During the down time I've been trying to learn a bit about making computer generated pictures using ray tracing programs.

The reason for this is simple. Often a great deal can be communicated through nice pictures that would be awkward or opaque through spoken word or text alone. At the same time poor quality pictures or representations of what you're attempting to explain can also obfuscate. So I decided that I'd had enough of making simple little pictures in MS-powerpoint. I wanted something more.

I downloaded POV-Ray and set to work. With a modest amount of mathematics and programming already under my belt, this turned out to be rather straight forward to use. Perhaps the simplest thing to make is a sphere, so I set about learning how to render pictures of a few spheres :

So there's my first attempt. A nicely colored row of spheres. It wasn't too hard to make actually. And to be honest, all I really need to know how to make are spheres. lots of them. LOTS AND LOTS OF THEM.

One of the systems near and dear to me is the surface of a particular gold crystal facet (though to be sure, the other facets are interesting too as are plenty of other crystals). It's a square cut through the face-centered-cubic lattice of gold atoms. The top row of atoms the rearranges itself into a hexagonal pattern. The hexagonal pattern can then be one of two possible orientations (rotated 90 degrees from each other). Furthermore because the surface atoms do not line-up perfectly with the atoms underneath, the surface ends up rippled and crumpled in a particular way.... See? I could keep going and going about the positions and so forth, but a simple picture would be sooooo much better.