RayJackONE - Waveguide Bavarian Style
The figure shows a polymer optical fiber (POF) forming a pretzel-shaped knot. Some of the rays leak out at the bendings where the radius of curvature is too small for total internal reflection.
Clearly, there is no predefined “pretzel surface” in #RayJackONE, but with the #python scripting environment, you can build one as a user-defined function that extrudes a circle about a base curve. For sake of simplicity, we chose the base curve to be a sequence of straight lines and circular arcs to form the pretzel.