FRED Technical Support FAQs

Installation and Licensing

My copy of FRED says it has an expiration date. I thought FRED licenses were permanent?

When a new copy of FRED is ordered, the USB dongle is shipped with temporary license authorization codes.  These temporary license authorization codes set the Software Expiration Date for the license, after which the program will stop working.  Once payment for the license has been received, permanent license authorization codes are sent to the end-user via email with instructions for updating the USB dongle to use the new codes.  After updating to your permanent license authorization codes, the Software Expiration Date will show “None”.

Where do I enter my license authorization? How do I update my license codes?

If your current codes have expired, a license authorization dialog box opens when you start FRED. To manually open the License Authorization dialog box, select Menu > Help > License Authorization from the menu.


Upon renewal of a FRED license, Photon Engineering sends new authorization codes to the registered user with instructions for entering these codes into FRED.

Do I need to uninstall older versions of FRED before installing a newer version?

No, you do not need to uninstall older versions of FRED. The newer version is installed in a separate directory with a path name corresponding to the version number.


Note: Remember that FRED files are not forward compatible. A FRED file saved in a newer version cannot be opened in prior versions of FRED.

Where can I get the USB key drivers?

FRED automatically installs the necessary USB key drivers, but there may be instances when a standalone key driver must be installed manually. This installer is included in the FRED installation directory at <install directory>\Utilities\Sentinel Protection Installer.exe.


Note: Please make sure to remove all USB dongles before installation.


Another Note: You can also find the Installer file and associated User Guide on the Gemalto website here:

Sentinel Protection Installer executable file

Sentinel Protection Installer User Guide

Can I use multiple network USB dongles on the same computer?

Yes, multiple network USB dongles can be used on the same computer.  Available licenses are the sum total of the network keys. Licenses are checked out from the USB keys in the order they were plugged into the computer.  A network license monitor can be accessed on the license server by navigating in a web browser to the address: http://localhost:6002.

I recently upgraded FRED, and my network license stopped working.

Upgrading a network license to the most recent version of FRED is a two-part process that includes 1) the installation of FRED on the local PC, and 2) the upgrade of the Sentinel License Server on the server. Verify both have been done. If not, the Sentinel Protection Installer can be downloaded from their website at:


  1. Select the following search options: User Category = End User, Product = Sentinel SuperPro, Operating System = Your Operating System,
    Type = Runtime and Device Driver, Language = Your Language
  2. Click Search.
  3. In the Search Results table, make sure to select the option that includes the FULL installer, not just the driver.
  4. Click I Accept at the bottom of the End User License Agreement.
  5. Click on the Download link in the Knowledge Base article to begin the download.


Also, see FRED’s Online Help topic entitled “Safenet Hardware Key – Network Setup” for more information.

Where can I find help to install FRED on my network? For example, how do I set up a FRED network key?

See FRED’s Online Help topic entitled “Safenet Hardware Key – Network Setup” for more information or read our Network Key Setup Guide for detailed instructions.


What is the recommended computer configuration?

While we don’t recommend a specific manufacturer or model, the following items should be considered when selecting a computer to run FRED:


  • FRED only runs on Windows. We recommend Windows 7 or newer (XP is no longer supported).
  • FRED performs multi-threaded calculations on up to 17 threads while FRED Optimum supports up to 63 threads.  Any number of threads beyond the limit for your version of FRED are not used.
  • Many components of FRED, such as BASIC scripting calculations and model updating, are not multi-threaded. Therefore, high-speed processors are advantageous.  In many scenarios, performance is better for a smaller number of fast CPUs compared to a larger number of slow CPUs (e.g., 16 cores at 3.2 GHz vs. 24 cores at 2.4 GHz).
  • We recommend between 16 and 48 GB of RAM to avoid buffer overflows that may occur when working with large raytraces.
  • Sometimes, buffering cannot be avoided (e.g., when you need to trace more rays than can be processed with the available RAM).  For this reason, it is beneficial to have a system with a high disk I/O. This stands for input/output, which is the speed of data transfer between the hard disk and the RAM. A solid state drive (SSD) is also recommended.
  • While FRED and FRED Optimum do not leverage GPUs for computing, the user experience and model editing are much improved with a quality graphics card. Photon Engineering has had reliable performance with NVIDIA NVS series graphics cards.
  • FREDmpc does leverage GPUs for raytracing and analyses. An NVIDIA GPU board is required to use this functionality. Please refer to the FREDmpc page for more information about this product.

Will FRED Optimum perform my calculations faster than the standard version of FRED?

FRED Optimum can take advantage of multi-threading operations on a maximum of 63 threads while FRED can only use a maximum of 17 threads. Therefore, to achieve the best possible performance, it may be advantageous to upgrade your computer to leverage the maximum thread limits available in FRED Optimum.


For a full features list for both versions, visit our website’s FRED Software page.

My 3D visualization view is slow and unresponsive. What can I do?

Photon Engineering has adhered strictly to the OpenGL standard, but sometimes, graphics card drivers may cause problems. Try changing the pixel format preference by selecting Tools > Preference from the menu, clicking on the Visualization tab, and setting the pixel format to “Fast”.


Note: This change does not take effect until you open a new FRED document.

My 3D visualization view freezes and/or crashes. What can I do?

Photon Engineering has adhered strictly to the OpenGL standard, but sometimes, graphics card drivers may cause problems. The following solutions are recommended:


  1. Select Tools > Preferences from the menu and click on the Visualization tab. Set the pixel format to “Safe” to enforce a software rendering mode. Please note that any changes to FRED preferences do not take effect until a new FRED is opened.
  2. Use the GLView.exe utility included with your FRED installation to determine an acceptable OpenGL hardware rendering mode for your graphics card.  Please see FRED’s online help topic entitled “Adjust the OpenGL pixel-rendering mode” for a detailed description of how to use this utility.  In general, choose a pixel mode in which the “letter cube” of the GLView.exe utility rotates without flickering. (This may not necessarily be the fastest rotation.)
  3. Download and install the latest video drivers from your manufacturer’s website.

My computer crashed, and I didn't save my FRED file. Anything I can do?

By default, FRED autosaves one “level of undo” in the Undo directory. So, one action can be undone by selecting Edit > Undo from the menu. That action is stored in a *.fru file or *.frs script in the Undo directory.


The number of autosaved FRED documents may be increased by selecting Tools > Preferences from the menu, then clicking on the Miscellaneous 2 tab, and then using the up or down arrow to change the “number of levels of undo”. The autosaved*.fru files are named “FREDUndoXXXXXXX_Y.fru”, where X represents the timestamp of the autosave and Y indicates the undo level. However, FRED only autosaves one, the most recent, script (MostRecentScript.frs) file.


To recover a *.fru file, locate the Undo directory and change the file’s extension from “fru” to “frd”. You can then open or move this file as you normally would.


To recover the most recent script file, locate the file in the Undo directory and open it as you normally would any script file. You can then save this file as you normally would.


Note: The default Undo directory is “C:\Documents and settings\<username>\Local Settings\Temp\Fred Undo”.  You can change this by selecting Tools > Preferences > File Locations from the menu, then scrolling through the file list, and then editing the entry for “Undo directory”.


Another Note:  To have FRED automatically search the Undo directory and recover the most recent *.fru document,  make sure “Allow about recovery” is selected as a preference. To do this, select Tools > Preferences from the menu, then click on the Miscellaneous tab, and check the “Allow abort recovery” checkbox.

Why don't I see the expected speed improvements with my multi-core computer?

Hyper-thread technology creates virtual CPU cores which do not have the same functionality as physical CPU cores. Therefore, the expected linear speed scaling does not apply. Keep in mind that performance scaling can be dependent on the specific construction of the FRED model. For example, the types and organization of surfaces in the model affect how well the raytrace scales with the number of threads. Also, remember that a raytrace’s Trace and Render option is a single-threaded calculation which doesn’t use a computer’s additional cores.

I lost my window! OR I lost my toolbar!

FRED’s user interface is extremely flexible and customizable. Toolbars and windows can be floated or docked anywhere on the screen. If something is moved off the screen or is no longer visible, it can be restored.


If you have “lost” a toolbar, first try to reset it by selecting View > Customize > Toolbars from the menu and clicking on the Reset button.


If that does not solve the problem or if you have “lost” a window (e.g., the Output Window), you will need to run the FRED executable file with the default window settings. To do this:


  1. Open a Command prompt in Windows.
  2. Change to the Bin directory of your FRED installation (e.g., cd “C:\Program Files\Photon Engineering\FRED 14.40.0\Bin”).
  3. Run the FRED executable with the command line option /NoLoadWindowStates (e.g., Fred.exe /NoLoadWindowStates).


How can I model a partially coherent source in FRED?

A partially coherent source can be achieved by simulating an extended source as a collection of point sources emanating from different locations (for finite conjugates) or directions (for infinite conjugates).  Each individual source will be coherent, but incoherent, in relation to all other sources. In FRED, this is achieved by using different wavelengths.  An example of implementing a partially coherent source can be found in the FRED Sample Files folder here: <installation dir>\Resources\Samples\Tutorials & Examples\examplePartialCoherenceDiffractometer.frd.


Note:  For more information, please read our Knowledge Base article, “Michelin Stellar Interferometer“.

How can I model a solar source?

The method for defining a solar source in FRED varies depending on the required accuracy of the model. Parameterizing the source depends on the time of year, time of day, longitude and latitude, weather conditions, etc. In its simplest form, the procedure below can be effective:


  1. Create a plane source with randomized ray positions and directions into an angular range (the subtense of the solar disk, about 0.5o).
  2. Add the wavelengths and weighting appropriate for a blackbody source such as the sun.  This can be accomplished by creating a blackbody spectrum. See FRED’s Online Help topic, “Spectrum – Blackbody” for details.
  3. Scale the wavelength weights by the atmospheric transmission values to account for weather or regional conditions.
  4. Set the power of the source in the Power tab appropriately for the solar irradiance value and the size of the system aperture.

The approach described above is implemented semi-automatically when using the Solar Source (simple) type of Source Primitive.

More complex models can be achieved by using theory such as the Bird Model ( The diffuse radiance from the atmosphere can be considered isotropic and specific data can be obtained regarding the wavelength spectrum.


Why doesn’t my analysis surface show the results of multiple passes?

For a discussion of this issue, please read the “Application Notes: Multiple ray pass analysis” subsection of FRED’s Online Help topic, “Analysis Planes Overview”.

Is there any way to customize my chart view?

Custom chart views can be created by using the “Advanced” controls of the chart viewer and FRED’s Preference settings.  For a discussion on this application, please read FRED’s Online Help topic, “Chart Viewer – Chart Customization” or read our Knowledge Base article, “Customizing Charts“.

I tried to display my analysis in the visualization view, but I don't see anything. What's wrong?

If a texture map display fails when called from the Analysis Results Nodes, a warning message displays in the Output Window. If a texture map display fails when called from the Chart Viewer, only a gray surface is displayed.


The number of pixels that can be displayed in the 3D view as a texture map is limited by the capabilities of a computer’s graphics. By default, FRED’s pixel mode is set to “safe”. Typically, texture maps up to 1024 x 1024 pixels are properly displayed in this mode. Hardware accelerated modes should allow for proper display of texture maps with larger numbers of pixels.


Note: See FRED’s Online Help Topic, “Preferences – Visualization” to change FRED’s default settings.

Rays and Raytracing

How many rays can FRED raytrace?

FRED can raytrace and analyze up to 263 rays.

Why am I unable to write frame #a to page file #b...?

This error message indicates the likelihood that security software is interfering with with FRED’s read/write operations. Please consult your IT department for information regarding recent updates to your security software.

I am unable to allocate memory for RayBuffer (RBV). What should I do?

This can happen when the minimum free hard disk space is less than the amount required for the Ray Buffer pagefile. Please read FRED’s Online Help topic, “Troubleshooting – Unable to allocate memory for RayBuffer (RBV)” or our Knowledge Base article, “FRED Preference Optimization” for more information.

I have received the error "Insufficient diskpace - unable to create another ray buffer pagefile". What should I do?



How do I attach analysis planes to NURB surfaces?

The parametric construction of NURBs is fundamentally different than other native FRED surfaces, which can lead to difficulty in positioning or attaching analysis surfaces to NURBs.  Unlike the native FRED surfaces in which the origin is definite and known, imported CAD models can contain NURB surfaces of arbitrary shape, size and position.  This flexibility leads to a fundamental question: What point on the arbitrarily shaped NURB surface becomes the origin after import?  For a detailed description on attaching analysis planes to NURB surfaces, please read the NURB surface origin section of FRED’s Online Help topic entitled “File – Import CAD” or read our Knowledge Base article, “CAD Surface Position and Orientation“.

How can I create some basic shapes in FRED?

Please see FRED’s Online Help topic entitled “Creating Basic Shapes”.

My surface doesn't look right, but I know I've entered the information correctly. What should I check?

If you are absolutely positive that the surface information is correct, the cause is most likely due to visualization settings.  Try increasing the tessellation (decreasing the tessellation scale size) for the selected entities.  For more information on the visualization attributes, please see FRED’s Online Help topic entitled “Visualization Attributes”.


I get the message "Error - Not enough storage is available to complete this operation". What should I do?

This message is encountered after having written a FRED document out to a *.frs file and attempting to run the script in v9.50 or earlier.  The solution to this error message is to remove the lines “Sub Main” and “End Sub” from the script file before running.

How do I manipulate the position/orientation of an object in script?

Manipulating the position and orientation of an object through the scripting language is accomplished by using the T_OPERATION structure and the linear transformation commands.  You can find a list of linear transformation commands in FRED’s Online Help topic entitled “FRED Commands by Usage”. Our Knowledge Base article, “Rotating Prisms by Scripting” shows an example of scripting position orientation. For a detailed discussion and more examples, please also read FRED’s Online Help topic entitled “Position / Orientation”.

Why aren't my script commands being recognized by the editor?

In v9.50 and later, script commands are separated into application level and document level.  Application-level script commands can be run without a FRED document open (e.g., math commands, file commands), but to be recognized by the script editor, document-level script commands must be run with an associated FRED document.


If only one document is open, FRED automatically associates the open script with that document.


If multiple documents are open, select Script > Associate with FRED Document from the menu, then select the document to associate with the script, and then click the OK button.


How do I customize a chart?

FRED uses a third-party chart control tool for the display and processing of visual data.  This chart control, a product of Component One, LLC, has a set of advanced settings and features which can be accessed and modified through FRED.  Additionally, there are two help documents for this component located in the directory C:WindowsHelp with the filenames olch2d8u.chm and olch3d8u.chm, pertaining to the 2D and 3D chart controls.  An alternative way of accessing the chart help is by right mouse clicking in the chart view, selecting Advanced from the list menu and then clicking on the Help button in the dialog.


The fact that the chart controls are provided by a third party means that there are two steps for customizing the chart views, one for the chart control and one for FRED.  Please read the Chart Customization Reference Sheet for instructions.