The Developer Mode Options Menu

This menu controls a number of different simulator and developer mode options to help with creating your add-on content. The options available to you from this menu are listed below.




  • Pause Simulation

    When enabled, this will pause the entire simulation. This is not the same as the "Active Pause" available through the simulation options, as certain simulation events - like the passing of time - will still occur while in active pause, while pausing using this option will prevent anything further from occurring. This is disabled by default.


  • Disable Crashes

    When enabled, this tells Microsoft Flight Simulator to ignore any collisions with the terrain that would otherwise end a flight with a crash. This means that you can slew the aircraft around and if it touches anything it will simply "bounce" off of it. By default this option is enabled.


  • Local Time

    This slider controls the local time for the simulation. This is useful when you want to edit - for example - somewhere in the world that is currently in darkness.
    NOTE: This option is only available when flying in the simulation.


  • Visual Icing

    This slider controls the visual icing system and when set to 1.0 all materials that show icing will be visible. If the simulation is not paused (or on active pause) the aircraft may gradually de-ice over time and this value will visually decrease. By default this is set to 0.0.
    NOTE: This option is only available when flying in the simulation.


  • Windshield Rain

    Much like the Visual Icing slider, this option is for visualising the windshield materials when it is raining, and as such any changes made to the options here will be best viewed from inside the cockpit (ie: with the Developer Camera off).
    NOTE: This option is only available when flying in the simulation.Selecting this will open the following sub-menu:The Windshield Rain Sub-MenuThis sub-menu has the following options:

    • Override Rain Rate: When enabled, the rate of actual rainfall in the simulation will be overridden for the rate given by the Rain Rate slider. By default this is disabled.
    • Override Wind Speed: When enabled, the actual wind speed in the simulation will be overridden for the speed given by the Wind Speed slider. By default this is disabled.
    • Rain Rate: The rate of rainfall to be simulated, where 0 is none and 100 is maximum. This slider is only valid when Override Rain Rate is enabled.
    • Wind Speed: The current wind speed override, in ft per second. This value can go from -500 to 500, and is only valid when the Override Wind Speed option is enabled.




Debug Drawing

  • Sim Objects

    Selecting this will open the SimObject Containers window, where you can view general information and debug the various SimObjects in the current simulation scene. For more information, see here.


  • Sim Object Model Statistics

    Selecting this option will open the SimObject Stats window, where you can view very detailed information on the models and bitmaps used to render the different SimObjects in the simulation. For more information, see here.


  • World Objects

    This option will show certain debug information for world objects and markers in the simulation. You'll get "spheres" (spherical meshes) to show data like waypoints and also overlay text.
    Image illustrating The World Objects Debug Option


  • POI

    Selecting this option will show POI (Points of interest) with "spheres" (spherical meshes) in the simulation.
    The POI Sphere In The Simulation


  • Collisions
    When you hover over this option you will be presented with the following two checkboxes:
    The Collisions Sub MenuSelecting either (or both) of these will add debug drawing for the Simple Shape Collisions and for the Mesh Collisions of the different scenery and simulation objects (including the user aircraft):
    Example Of Simple Collision Shapes And Collision MeshesNote that the Mesh Collision checkbox will also render the Cockpit DRONE_COLLISION_IN mesh. Also note that if collisions are disabled in the engine for an object that has a collsions shape, then the bounding boxes will be rendered using dashed lines.


  • Flight Object Debug
    Enabling this option when within a flight or a mission will show the main Flight Object Debug window: Flight Object Debug Main WindowAnd may also show different sub-windows, eg:Flight Object Debug Sub-WindowsThis tool is for debugging the different mission calculators when in a flight, and each sub-window will display the internal logic for the different calculators available. These sub-windows can be filtered from the main window using the following input fields:
    • Description Filter: filters the sub-windows based on the description field in the calculator.
    • Classname Filter: filters the sub-windows based on the classname of the calculator.


  • Aircraft
    This option opens a sub-menu where you can access the various debug windows that are used to debug the performance of the current aircraft being flown. You can find all the information about these windows from the following section: Aircraft Debug Menu


  • Airports

    This option opens a sub-menu where you can enable airport debugging. For more information on the options in this sub-menu please see here.


  • Terrain

    This option opens a sub-menu where you can enable airport debugging. For more information on the options in this sub-menu please see here.




  • Display FPS

    Enabling this option will show the current FPS of the simulator as well ass some additional performance related debug information.
    The Debug FPS Overlay


  • Wireframe

    This enables the wireframe view of the simulation, where all models are rendered as wireframe meshes.
    Wireframe View Of The Simulation


  • Display Position

    Selecting this will open the Position window:
    The Position Debug WindowThis shows the position of the current selected aircraft within the world. Each individual positional value can be copied to the clipboard using the Copy button, or you can click the Log to file button to open a file explorer window and save out a text file with all of the data. Note that if you save the file you will also have to add the extension as part of the file name, for example "Position.txt".


  • Lens Distortion

    This option enables or disables the lens distortion effect.


  • Volumetric Atmospheric Effects

    When disabled, this will remove all the volumetric effects from the simulation scene (ie: it will disable alll the clouds). This can make it easier to see what you are doing when working on scenery or using the This option is enabled by default.


  • Ground

    The ground option will open a sub-menu with the following items:

    • Debug Tile: Shows debug information for the quadtile that the mouse is currently over.
    • Debug Terraforming: Shows debug information for any terraformed areas in the scene.
    • Detail Maps: When enabled, detail maps will be added to the terrain to increase fidelity. Disabling this removes these maps. Mouse over the image below to see the difference (this option is on by default).
      Card Back Card Front
    • Only Lighting: Disables the terrain surface materials and shows only the terrain lighting.
    • Altitude Isoline: Shows the terrain textured with isolines, indicating height.
      Terrain Isolines Drawn Over The Simulation Landscape


  • PBR Channel

    From this option you can view the different PBR channels used in the generation of the terrain and other assets. By default this will be set to disabled, but you can select other options from the sub-menu. For full details please see here: Debug PBR.


  • Debug Model LODs

    Enabling this option will open the Debug LODs window where you have multiple options to show the LODs and LOD-related data overlaid on the simulation. For full information on the options present in this window, please see the Debug LODs section.




  • Load Models Asynchronously

    This option, unlike most of the other options, would usually be enabled or disabled before actually starting a flight. The option is enabled by default, which will mean that if the chosen aircraft for the flight uses any WASM modules, the module will be compiled at the same time as the flight is loading (it will be compiled asynchronously). However, disabling this option means the module will be compiled on it's own before the sim continues to load anything else. This option is only really useful for those add-on creators that are making WASM modules and want to debug them, as disabling this option may mean that Microsoft Flight Simulator will "freeze" for a time while the WASM module is compiled, before loading a flight.


  • Fast WASM Compilation
    Enabling this option will permit the WASM modules to be compiled a lot faster, as it basically bypasses the LLVM optimisations - which is what normally slows down compile time. Essentially it has the following effect:
    • No optimisations are done, and the resulting DLL literally the exact same WASM file.
    • Debugging is available.
    • Compilation is much faster.
    • Compatible with Visual Studio Debugger Extension.
    However the downside for this is that the resulting gauges will be far less performant (which isn't normally an issue when testing or debugging).
    When this option is unchecked, the following will be true:
    • Debugging is not possible.
    • Breakpoints may still work (it will depend on the configuration of Visual Studio) but variables are optimized so they are unreadable.
    • Very optimiseaed - the code will run faster (with a subsequent gain in FPS).
    • Compilation is slower.


  • Display WASM Debug Window
    Enabling this option will show the WASM Debug window, explained in more detail here: WASM Debug




IMPORTANT! Features placed in this section are those which may - or may not - become final features of the SDK. Using these features is done at your own risk as they may impact the stability of the simulation and DevMode tools.

NOTE: Previously this menu showed these options:
    - Use NanoVG for XML Gauges
    - Enable Replay Panel
These options were moved to the in-simulation options menu, and as such are now documented here: Experimental Features.


  • Smart Docking System
    With this option you can have the simulation render within the imGUI framework of windows. What this means is that instead of having the game render under the various DevMode windows, you can instead have it render within a window and so this permits you to position alll the DevMode windows around it and customise the layout to suit your own preferences, all the while still seeing the entire scene unobscured by overlaid windows. Offscreen Rendering Of the Main Simulation Within An imGUI WindowIt is worth noting that when this option is enabled, you won't actually be able to resize/move the simulation window. Instead, resizing or docking the other DevMode windows will automatically resize the simulation window to fill in any empty space. For this reason, while using the option, you can't dock any window in the central node as this would result in no space left for the simulation to be rendered. It is also worth noting that some UI elements of Microsoft Flight Simulator may be sized incorrectly when viewed using the dynamic docking system. This is something that may be resolved in future updates.


  • Debug Weather
    Selecting this option will open the Debug Weather Sim window, which is described in full on the following page:


  • Debug Vegetation
    When enabled, this option will open a new window with debug information related to the drawing of vegetation in the scene: The Debug Vegetation Window This window has all the data that is related to the vegetation rendering, and is directly affected by the two in-sim options for Terrain Level Of Detail and Tree density: The Sim Settings For Vegetation Density And Rendering Both these options will affect how the vegetation is rendered along with the values that the debug window displays. You can also visualise the difference these options make by enabling the Show Vegetation In Red option, which will then shade all the vegetation bright red and permit you to better visualise the impact of the different detail options, as shown in the image below:

    Visualisation Of Render Options On Vegetation




  • Default VR API
    This section allows you to change the default API used to communicate with the VR hardware. When selected, you will be presented with the following two options:
    • Fake: is a "fake" API that does not require any VR hardware to actually be connected to the computer. This can be used to simulate the presence of a VR head mounted display.
    • OpenXR: is the default API that Microsoft Flight Simulator uses. It is compatible with most VR devices available currently, eg: SteamVR, Oculus, Windows Mixed Reality, Varjo.
    When Fake API is active, the user can control the rotation of the camera by holding shift+mouse left click and moving the mouse or using the gamepad left stick.