Dielectrics

Here's a couple of images of a pieces of "green glass." In this first image, both mediums have an index of refraction of 1.0:

In this next image, the index of refraction starts as 1.00, but then changes to 1.39:
Reflections are currently not implemented. Notice where total internal reflection begins? Notice how the rays are bent away from the viewpoint? This is what I would expect when the index of refraction becomes greater.

Here's an example where the transition is from 1.39 to 1.00:
Notice how the rays are bent towards the viewpoint?

I suspect that these images may be correct, well, as correct as they can be without implementing reflections and using a Fresnel term to make sure that energy is conserved.

I'm using Snell's law to calculate the direction of the refracted rays