Unity: Preserving static object/data between editor and play

Question

I made offline Waypoints Network generator, which is able to construct waypoints network in editor so we can move or remove the waypoints during the editing process. However I need some way to reference the waypoints network from different objects in play mode and I really like the singleton approach. My idea is:

I have 3 scripts: WNNetwork, WNNetworkObject and WNNetworkData.

WNNetworkData is simple ScriptableObject, which holds the calculated data.

[System.Serializable]
public class WNNetworkData : ScriptableObject {

    // Data of waypoints network
    public List<WNWaypoint>     waypoints = new List<WNWaypoint> ();
    public WNKDTree             tree      = null;

}

WNNetworkObject is MonoBehaviour scripts that is attached to GameObject and it is use to update, re-generate or delete the waypoints network.

public class WNNetworkObject : MonoBehaviour {

    #region Public Variables

    // Properties of waypoints
    public float size                   = 1f;
    public Color color                  = Color.cyan;
    public Color colorSelected          = Color.white;
    public Color colorLine              = Color.white;
    public float lineWidth              = 0.5f;
    public WNWaypoint.GizmosType type   = WNWaypoint.GizmosType.CUBE;

    // Parameters for network generation
    public float maxClusterRadius           = 2;
    public float neighborsThreshold         = 10f;
    public bool  doNeighborsSimplification  = true;

    // Others
    //  public GameObject queryTarget;

    #endregion

    #region Life-cycle

    void Awake () {
        DontDestroyOnLoad (this.gameObject);
    }

    void Start () {
        Debug.Log (WNNetwork.data);
    }

    #endregion
...
}

This is how it's look in inspector editor:

WNNetwork Inspector editor

The last script is WNNetwork, which is basically a wrapper class holding static reference to WNNetworkData and WNNetworkObject, so I can easily access both.

public class WNNetwork {

    public static WNNetworkObject root;
    public static WNNetworkData data;

...
}

I also created an EditorScript, so I can create all objects from Menu, here is the creation part.

public class CreateWaypointsNetwork {

    [MenuItem("GameObject/Create Other/Waypoints Network")]
    public static void Create ()
    {
        WNNetworkData   data = ScriptableObject.CreateInstance <WNNetworkData> ();
        GameObject      go   = new GameObject ("WaypointsNetwork", new System.Type[]{typeof(WNNetworkObject)});
        WNNetworkObject root = (WNNetworkObject) go.GetComponent<WNNetworkObject> ();

        WNNetwork.data = data;
        WNNetwork.root = root;

        AssetDatabase.CreateAsset (data, "Assets/WaypointsNetworkData");
        AssetDatabase.SaveAssets  ();

        EditorUtility.FocusProjectWindow ();
        Selection.activeObject = go;
    }

}

The thing is, when I create the Waypoints Network everything works in editor, every object seems to be successfully created and I can edit the waypoints. But as soon as I hit the play button, the WNNetwork is reset and all static variables are equal to null. The Network itself seems to be preserved, because every waypoint still have reference to all its neighbours, but I cannot access the data.

I know I am doing something terrible wrong, but I'm unable to determine what, I'm still not so familiar with Unity.

Thanks for any help.

Answer 1

Simply unity doesn't serialize static fields (even if they are of a serializable type).

When you switch from editor to play mode you are deserializing/serializing data, so you will end up losing everything stored into static fields.