Several procedures in OpticStudio are saved temporarily before saving permanently; one such procedure is the non-sequential ray trace. When the ray trace is finished, it saves as a .ZRD file to the same directory as the lens (.ZMX) file; but before it’s finalized, it is directed to the standard Windows temp folder.

When millions or more rays are traced, especially with ray splitting engaged, ZRD files can quickly become extremely large (many GB). When this error appears, it is a result of insufficient memory in one of two places. The first is the Windows temporary files folder. To find the folder and clear its contents, search “%temp%” by right-clicking on the Windows Start icon, as shown below. (When clearing the contents, make sure that all applications are closed.)

If the temp folder is cleared and you’re still having trouble, then the fault may lie with your default drive (usually the C: drive). You should check to make sure that there is sufficient space on there. In general, if the drive is over 85% full, you will start to see slow speeds and memory errors.

One solution can be to redirect the temp directory to another folder: http://answers.microsoft.com/en-us/windows/forum/windows_7-files/change-location-of-temp-files-folder-to-another/19f13330-dde1-404c-aa27-a76c0b450818?auth=1. That is for Windows 7, but the method works also in Windows 10.





If you still have issues, try to modify some settings to reduce the overall size of the ZRD file.


For instance, what is your minimum relative ray intensity setting (System Explorer > Non-Sequential > Minimum Relative Ray Intensity)? Could you get away with fewer rays? Do you have scatter profiles set? If so, there may be some settings we can adjust there to improve the signal and reduce the number of rays in the ZRD file as well, such as Importance Sampling and others.





When a ZRD file gets extremely large (~100GB, say), saving it becomes an issue but reading it will also become an issue. So basically working with a big ZRD file will be very time consuming. For these reasons, it is beneficial if possible to be able to reduce the overall size of the simulation results.