Q: How do I save my Pro/Engineer model so it can be imported into Photopia?

A: For Pro/E 2001, use the following instructions. The specifics may vary for other versions, but the overall process will be the same:

1. Always work in assembly mode. If you have a large assembly (a car, for example) then make your “lighting fixture” a sub assembly and then assemble it into the main assembly once you are underway.
2. Start the assembly with your best 0,0,0 part - usually your reflector or your lamp - as the first component. Try to constrain all other parts to datums, axes or Csystems based on this part. Never “fix” a component - always fully constrain it.
3. STL out the parts from within your sub assembly. Use File / Save As and select .stl.
4. Pro/E will default the exported filename to the same name as the assembly. Because you need to retain individual parts in Photopia, you will need to delete the assembly name in the file window, and instead enter the name of the first component you wish to export to Photopia. Select OK when done.
5. In the STL Export dialogue, select “Include” and pick your first part for export. (If you have several parts which will take the same optical materials you can add these to the selection). Pro/E will tell you how many parts you have selected. “Reset” will let you restart the selection process. Next select your coordinate system. Default will use the default CSYS of the assembly. If you created a separate one as your optical center, then make sure to select it.
6. Select binary or ASCII, Photopia will read either.
7. Select “Allow negative values” as this will keep your parts centered about 0,0,0.
8. Select Angle Control and enter a value of 1.
9. Select Chord Height, enter 0. Then select the Angle Control window again. The Chord Height will then default to the best available in this part.
10. Note, the Chord Height available to you will improve with higher part accuracy settings. It also seems to vary between exports from assemblies and from part mode. This is probably controlled by the accuracy setting of the part versus the assembly file. Call PTC for clarification. Investigate what your settings will look like in Photopia by clicking “Apply” and spinning the resulting image. If you are satisfied click OK and save the file.
11. Repeat this procedure with each individual part.
12. Upon import into Photopia, you can select the entire set of files you created. The parts will assemble within Photopia as they did in your Pro/E sub assembly.