There are a few items to be aware of with polygon objects.

• Make sure that the combination of rectangles/triangles defined in the POB file form an enclosed volume if it is being used as a volume (POB objects can also be made shells via the “Is Volume” flag in the NSC Editor).
• When defining rectangles, do not use a “bow-tie” pattern when connecting vertices.  This will result in erroneous ray tracing.
• There is no fixed upper limit as to the number of triangles a polygon object may contain.  This is determined by the amount of real or virtual RAM the computer has available.  Each triangle takes about 100 bytes of memory.  However, ZEMAX often maintains multiple copies of the lens data simultaneously, and so a good rule of thumb is that ZEMAX will need 500 bytes of RAM for each triangle.

Included with ZEMAX is a sample macro which may be used to create various polygon objects, without requiring you to define every single vertex; etc.  The macro is named Polygon.ZPL and requires a few input values from the user:  radius of the containing circle (note that this does not require the polygon object be circular), the number of edges along the “circle,” the length of the “tube”, and the number of sections along the length.  For more details on how the macro generates the POB file, please refer to the syntax of this file located in the ZEMAX>Macros directory.