# Debug LODs<no value>
{{< image-center
    src="images/2_DevMode/menus/debug/debug_lods/debug_lod_1.png"
    alt="The Debug LOD Window From The Options Menu" >}}

This window is opened from the DevMode [Debug](../../debug_info/) menu, and can be used to help debug the different {{< glossterm >}}lod{{< /glossterm >}}s used by the models in a scene. This window has the following options:


-   ##### Display Interior Models

    Selecting this will display information about the interior model LODs currently being rendered. This will also show some [Additional Options](#additional-options).


-   ##### Display Exterior Models

    Selecting this will display information about the exterior model LODs currently being rendered. This will also show some [Additional Options](#additional-options).


-   ##### Display Inactive Models

    This option can be used to display the LOD details for "inactive" models, and it will only work when you *also* have **Display Exterior Models** enabled. An "inactive" model is one that the simulation has hidden from the scene, either because it is outside of the LOD range or because the current graphics settings have disabled it. They will usually be shown with cyan text and a LOD level of -1:  

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_16.png"
        alt="Example Of The LOD Debug When Displaying Inactive LODs" >}}


-   ##### LOD Limits

    This option activates LOD limits, enabling you to preview the LOD system (described here: [LOD Minsize Rules](../../../models-and-textures/modeling/landscape/lods/#h1)). Changing the setting here will force a reload of all BGL files, however if you are debugging a SimObject, you will need to set this before starting a flight, or manually reload the SimObject. The available settings here are:

    -   **Default** - LOD limits will be enabled for new packages only.
    -   **Forced Active** - LOD limits will be enabled for all packages.
    -   **Forced Inactive** - LOD limits will be disabled for all packages.


-   ##### Enable Mesh Display Distance

    This option permits you to toggle on/off the mesh display distance. When *on* meshes will only be displayed up to a distance of 3km from the camera. When *off* the display distance is essentially infinite.


-   ##### Freeze LOD Selection

    When enabled, LOD selection will be frozen and no objects in the scene will update it's LODs. This permits you to set a LOD level for an object based on the camera position, freeze the LODs, and then move the camera closer to get a good look at how the LOD model looks in scene.


-   ##### Force User LOD 0

    This option will be **on** by default and will force the user aircraft to always show LOD 0 (the most detailed). Disabling this option will permit the user aircraft to go through the available LODs when you change the exterior camera.


-   ##### Enable Force Active LOD

    Enabling this option will show a LOD slider:

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_3.png"
        alt="The Force Active LOD Slider" >}}
    
    Changing this slider will alter the LODs for all objects being rendered, permitting you to check out lower detailed LODs even when the camera is right next to the object:  

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_2.gif"
        alt="A Truck Going Through The LODs" >}}


-   ##### Instance Stats

    This section, when expanded, shows the status for the different object instances being loaded and/or processed currently for the camera view.

 

Note that the text (and bounding spheres) used to display LOD information will be colored to give a visual representation of this value, using the following scale:

{{< image-center
    src="images/2_DevMode/menus/debug/debug_lods/debug_lod_7.png"
    alt="Colour Coding For LOD Screen Size Percentage" >}}


{{< Callout context="note" title="NOTE" icon="outline/bulb" >}}

This value will be affected by the <strong>Objects Level Of Detail</strong> setting from the <strong>General Options</strong> of the main simulation menus.This color will be shown <em>except</em> when the <strong>LOD Limits</strong> options are activated, in which case the text and bounding spheres will be colored based on how optimised the LOD values are, where:

{{% spacer %}}

<ul>
    <li><strong>RED</strong> - The LOD is unoptimised and needs to be fixed</li>
    <li><strong>ORANGE</strong> - The LOD is borderline optimised, but may have issues</li>
    <li><strong>GREEN</strong> - The LOD is optimised</li>
</ul>

{{< /Callout >}}


### Additional Options

If you enable **Display Interior** and/or **Display Exterior** Models, then you will be presented with the following additional options:

{{< image-center
    src="images/3_Models_And_Textures/LODs/debug/lod_debug_2.png"
    alt="Additional Model LOD Options" >}}

The options available here are:


-   ##### Display Bounding Spheres

    When this option is enabled, "bounding spheres" will be shown for all the models. These spheres are used as part of the screen size calculations as well as other internal calculations, and are a good way to visualise the approximate size and position of objects.

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_5.png"
        alt="An Example Of A Bounding Sphere In The Simulation" >}}
    
    The color of the bounding sphere is a visual representation of the approximate LOD screen size following the same scale as that shown below in the **LOD Screen Size** description.


-   ##### Display Only Models With A Single LOD

    Selecting this option will change the debug display to only show those object instances with a model that has only a single LOD. This can be used to pinpoint objects that may be unoptimised for the simulation.


-   ##### Display Animated State

    When this is enabled, the model will be shown with a text shoing either ON (if the model is currently set to animate) or OFF if the model is not set to animate or has no animations.


-   ##### LOD Screen Size

    When this is enabled, there will be a value shown beside the LOD data for each object instance visible:

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_6.png"
        alt="LOD Screen Size Data Being Shown In The Simulation" >}}

    This value is the approximate size on screen for the object based on the *bounding sphere* (and not the object model). The value is calculated as a percentage.


-   ##### LOD Draw Count

    This will draw the current draw count for each LOD in the scene:  

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_14.png"
        alt="The LOD Draw Count Visualised In The Scene" >}}


-   ##### LOD Face Count

    This option will add the model LOD face count to the display:  

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_8.png"
        alt="The Face Count Shown In The Simulation" >}}


-   ##### LOD Limits: draw count

    Enabling this will show the draw count for the currently displayed LOD as well as the maximum number of draw calls for that LOD. Draw counts are influenced by the number of vertices and the number of materials that are associated with an object (although there may be other factors too).
    
    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_13.png"
        alt="The LOD Limit Draw Count Displayed In The Simulation" >}}


-   ##### LOD Limits: vertices

    Enabling this will show the the number of vertices for the currently displayed LOD as well as the maximum number of vertices for that LOD.  

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_15.png"
        alt="The LOD Limit Vertices Displayed In The Simulation" >}}


-   ##### Wanted LOD

    When enabled, this option will show the LOD that is to be loaded for each instance for it's LOD level:  

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_9.png"
        alt="The Wanted LOD Option Shown In The Simulation" >}}


-   ##### Loaded LOD

    This option, when enabled, will show a *bitmask* for the different LODs available to the model. Each value of the bitmask represents a LOD level, and if it is 0, the LOD is not currently loaded, while if it is 1, the LOD is loaded in memory:  

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_10.png"
        alt="The Loaded LOD Overlay In The Simulation" >}}


-   ##### Available LODs From Template

    When this is checked, the LOD display will include a bitmask, preceeded by "T:". Each value of the bitmask represents a LOD level, and if it is 0, the LOD is not currently loaded, while if it is 1, the LOD is loaded. This value is *not* instance specific like [Loaded LOD](#loaded-lod), but across *all* instances of an object model currently in the world. For example, if *instance A* has LODs 2 and 5 loaded, but *instance B* only has has LOD 1, then *both* instances will show "T: 0110010".  

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_17.png"
        alt="The Available LODs From Template Display In The World" >}}


-   ##### Display Name

    Using this option you can display a name for each of the object instances being displayed. When you enable this, you can choose from one of 4 options:  

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_11.png"
        alt="The Display Name Options" >}}

    -   **Display Short Name**: This will show the "short" name for the object, taken from the XML filename.
    -   **Display Full Name**: This shows the short name along with the path to the package where the file is stored.
    -   **Display Package Name**: This will show the package name that has the object in it.
    -   **Display GUID**: This will show the GUID for the object.

    {{< image-center
        src="images/2_DevMode/menus/debug/debug_lods/debug_lod_12.gif"
        alt="The Different Display Name Options Overlaid On The Simulation" >}}