Two-Media Element: The two-media element contains two refractive media of equal volume. Place one two-media element anywhere in the simulation window. With Select depressed, you can move and resize the two-media element. You may place point light sources and beam projectors within the two-media element.

In the two-media element's Properties Box, you can select the media for the two halves of the object: air (default for upper half), water (default for lower half), glass, or diamond. The Properties Box lists the refractive index of each medium.