Help with making changes to scene with editor

Unity Engine
1

Hi everyone,

I’ve run into problems where changes to the scene performed by my custom inspectors are not preserved when I close Unity.

The first place where I have this issue is in a custom inspector for a script named “Constellation,” attached to objects with children with “Line” components. I tell the children to find a transform elsewhere in the scene (specifically, find a GameObject representing a star, based on its world position).

using UnityEngine;
using UnityEditor;
[CustomEditor(typeof(Constellation))]

public class ConstellationEditor : Editor
{
    public override void OnInspectorGUI()
    {
        Constellation constellation = target as Constellation;
        if (GUILayout.Button(“Set References”))
        {
            for (Line line in constellation.GetComponentsInChildren<Line>())
            {
                //  line will find a transform somewhere in the scene and reference it in a Serialized private field.
                line.FindReference();
            }
        }
    }
}

I also have a script called “StarField” which contains many GameObjects representing stars. Sometimes, I need to delete and load the stars, and I’ve attempted to implement those functions like so:

// setting up the custom inspector (sorry I got lazy this time)
public void LoadStars()
{
    if (File.Exists(Application.dataPath + "/starsData.csv"))
    {
        string dataString = File.ReadAllText(Application.dataPath + "/Resources/Stars - GameData.csv");
        foreach (string line in dataString.Split('\n'))
        {
            GameObject starObject = Instantiate(starPrefab, transform);
            // Do some other things to the star based on csv data.
        }
    }
}

public void DeleteAllStars()
{
    int childCount = transform.childCount;
    for (int i = 0; i < childCount; i++)
    {
        DestroyImmediate(transform.GetChild(childCount - i - 1).gameObject);
    }
}

As stated earlier, I’m unable to make lasting changes with these functions. Any help would be appreciated.

2

This is your magic sauce, right here:

3

@Kurt-Dekker The magic sauce doesn’t work for one of my problems. I’m trying to set a transform reference in another gameobject which is a prefab instance.

// This does not work.
Undo.RecordObject(player, "Set Reference");

// Nor does this.
PrefabUtility.RecordPrefabInstancePropertyModifications(player)

// Set a private Transform field of player to the transform of a Ball somewhere.
// player is a Prefab instance.
player.FindClosestBallReference();

“Doesn’t work” means that these changes don’t even persist through entering play mode, much less closing Unity.

In other news, I’ve solved my other problem with Undo.RegisterFullObjectHierarchyUndo. That was when I needed to delete all of my object’s children. So thanks for that.

4

Reading your response, I’m still slightly unclear if you’re telling me that Undo.RegisterFullObjectHierarchyUndo worked for the above or not? I thought that was the right one for anything transform-related… in any case, glad it’s working for you.

5

No, I had two problems to solve. Just ignore my last paragraph. Undo.RegisterFullObjectHierarchyUndo does not work to save changes made with player.FindClosestBallReference();, and neither does Undo.RecordObject nor RecordPrefabInstancePropertyModifications.

Undo.RegisterFullObjectHierarchyUndo takes the state of all a gameobject’s children, right? Even children of children?

6

I would defer to whatever the documentation says. I haven’t used it. If the documentation is unclear, you should indicate so at the bottom of the documentation page, because Unity does actually improve their documentation based on constructive feedback.