28.2. Options in mevislab.prefs

The syntax of mevislab.prefs is the syntax described in the MDL Reference. All settings must be contained in a "Settings" element like this (example):

  Settings {

    // show windows when network is loaded
    RestorePanels = YES

    // autoreload the mdl/script files when a window of a module is opened
    AutoReload = YES

    // autosave networks when changed
    AutoSave = YES


The settings file can contain any variable name. The value of a variable can be queried from scripting with MLAB.hasVariable, MLAB.variable, and MLAB.variableIsTrue. Variable names are case sensitive. Besides self-defined variables there are some pre-defined variables for various - sometimes very specialized - purposes, which are listed in the following table. This list does not include (with some exceptions) variables that can also be set from the Preferences dialog in MeVisLab.


This allows one to define additional user packages that should be available in MeVisLab.

This attribute has two sub-attributes pathRoot and path. pathRoot gives a root path to which all subsequent path are relative. path should usually be a pair of package group and package, separated by a slash. Example:

    PackagePaths {
      pathRoot = "C:/Users/a_user/Documents/Packages"
      path = MyPackageGroup/MyPackage
      pathRoot = "C:/Users/a_user/Documents/Development/MeVisLab"
      path = MyOrganization/Package1
      path = MyOrganization/Package2
Logfilefile path

Write all console output to the file given. Can use $(LOCAL) to address files relative to the settings file.


Show module panels when network is loaded. Also available from the Preferences dialog.


Autoreload the mdl/script files of a module when a panel of a module is opened (recommended for fast prototyping, no explicit module "reload" is required). Also available from Preferences dialog.


Auto-save networks when changed. Also available from Preferences dialog.


Will print messages when entering and leaving command handling scripting functions.


By default deprecated modules (or modules in other hidden module groups) do not appear in the module search. If this option is set modules by the current user will always be shown.


The author name for a module must be exactly the same as the user name in the Preferences dialog.


Override the location of the MeVisLab documentation, giving the base path as an URL. A suitable default would, e.g. be https://www.mevislab.de/docs/current.

UserSpellcheckFilefile path

MeVisLab has an integrated spell-checker (based on hunspell) for english texts in the module help editor. With this option one can add an additional dictionary file.

PreloadModulemodule name

With this option, modules can be loaded at startup of the IDE (they are created in some invisible network), which can in turn execute some code and, e.g., initialize preferences variables. This tag can be given several times.


The MeVisLab debug console by default refreshes immediately after each output to be always up-to-date (e.g. in case of crashes), but this can lead to problems with event handling and is slow. Disable immediate refreshes by setting to YES (then the console is only updated when MeVisLab is idle or processes events for other reasons).


Windows only.

Set extra directories from which to load DLLs. (MeVisLab ignores the PATH environment variable since version 3.7.) Several paths can be given separated by ';', but this entry can also be given more than once.

It is also possible to reference environment variables in a path with ${}, e.g. ${CUDA_PATH_V11_4}, or even ${PATH}.


Set the cache size for the ML image processing (in MB). Also available from Preferences dialog.

OverrideCursorDirectorydirectory path

Allows to specify a directory which can contain alternative mouse cursors to be used in Inventor scenes. See the comments in $(MLAB_ROOT)/MeVis/Foundation/Sources/MLInventorGUIBinding/SoQtViewerProxy.h.


Use Qt for rendering fonts in SoView2D and similar viewers if YES (default). Otherwise uses simpler font rendering engine without Unicode suport.


Font to use for font rendering.


Same as above, but only affects the simpler, not Qt-based font rendering.


Scale all MDL panels with this factor. Default is 1.


Used by the QuickView control, can define the QML style to use.


If set to YES, MeVisLab will not look for updated mdl/script files after first load. Used for application deployment. (Defaults to YES for applications, NO for IDE.)


Run MeVisLab with a low process priority.

SplashPenColorhex value

Set the color with which text is drawn on the splash screen. Must be a 6-digit hex value (without '#').


Don't show initialization messages on splash screen.


Set to NO to disable Python multi-threading support in case of problems.


Set the maximum number of threads to use by the ML image processing pipeline for image for standard image processing. The default is the number of virtual cores for the system.


Set the maximum number of threads to use by the GVR framework. The default is the number of virtual cores for the system. Also available from Preferences dialog.


If enabled time stamps in the log will be printed with a higher precision (precision depending on the system). This can be useful if the exact timing of events is important.


If this option is on, .mlab files won't store the position and state of module panels. This can reduce the changes displayed in diff tools when using version control systems.


Fix flickering of fullscreen panels with OpenGL content (for some setups).


If NO, call Debug mode tools (according to debug suffix of executable name) from MeVisLab if MeVisLab is in Debug mode. Otherwise always prefer the faster release mode variant. Default is YES.


Whether to store the module cache files in a directory outside the installation directory. Default is YES for macOS, NO for Windows and Linux.


If this option is set, pop-up menus don't show icons for their entries (on some platforms this is a no-op, as there are no icons shown anyway).


If this option is set, MeVisLab (and applications based on MeVisLab) will not display a warning if the current license is about to expire.