The Chief Ray tool generates chief rays based on the sources which are selected during the Chief Ray setup. These Chief Rays are then launched from the center of the sources and traces along the z-axis of the optical system. The user can click on the segment of the Chief Rays and apply CAD tools to measure position and analyse the affects the mechanical components have on them. In order to showcase this feature we can use one of the sample files. After opening up the ultrashort_throw_projector.asm assembly, this initial set up is given:

After that it is necessary to set STOP Object in the Advanced settings (RED A), first the Maximum chief ray position delta has to be set, for this example we will use 0.0254mm this value is the maximum delta that the chief ray may be displaced from zero. Secondly, the Stop Object has to be defined, the Stop Object may be defined within the Prepare for OpticsBuilder settings within Zemax OpticStudio and if the initial ZBD settings are set as non read-only the OpticsBuilder user can change the stop selection.

• Please note that all the Sample files have a Maximum chief ray position delta and a Stop Object set (RED B)

After that the Chief Ray within the Ray Geometry can be applied (Red C).

In order to do so, the next step is to define which sources are included and which sources are not. As the basic set up of the optomechanical system has now been changed, the user needs to re-run a Simulation. After the Simulation is run, it make sense to hide the rest of the rays in order to properly work with the Chief Ray, this can easily be done by navigating to the Simulation Rays section of the OpticsBuilder Model Tree, right-clicking the specific Ray bundle and then choose Hide (Red A).

The user can go ahead and click on any given Chief Ray (in this example only one source was chosen), and the short menu of the Creo graphics area pops up (Red B). The Chief Ray can now interact with all the mating and measurements tools found in Creo.