Showing nonserialized objects in the editor during playback

Unity Engine
1

I have a runtime-only object which is marked [NonSerialized], but I want it to show up in the inspector during playback for debugging/tuning.

Is there a sane way to do this? The only way I’ve found so far is to create a temporary object in the CustomEditor:

[CustomEditor(typeof(MyClass))]
public class MyClassInspector: Editor
{
    [Serializable]
    class MyDataHolder: ScriptableObject
    {
        public MyData myData;
    };

    public override void OnInspectorGUI()
    {
        DrawDefaultInspector();

        if(Application.isPlaying && MyClass.myData != null)
        {
            var holder = ScriptableObject.CreateInstance<MyDataHolder>();
            holder.myData = MyClass.myData;

            SerializedObject tempObject = new SerializedObject(holder);
            SerializedProperty myData = tempObject.FindProperty("myData");

            Editor e = Editor.CreateEditor(myData.objectReferenceValue);
            e.DrawDefaultInspector();

            DestroyObject(holder);
            DestroyObject(e);
        }
    }
}

That works, but it’s a pretty nasty hack. It’s probably harmless in practice, but is there a less dumb way to do this?

2

I found this code somewhere that creates a ShowOnly attribute.

The class for the actual attribute. This can be placed anywhere

using UnityEngine;

/// <summary>
/// This will allow the use of a [ShowOnly] Attribute in scripts making a value read only in the Editor.
/// This script is complimented by one in the Editor folder that is for drawing the read only value.
/// </summary>
public class ShowOnlyAttribute : PropertyAttribute
{

}

This is the property drawer for the ShowOnly attribute. This must be placed in an Editor folder.

using UnityEditor;
using UnityEngine;

[CustomPropertyDrawer(typeof(ShowOnlyAttribute))]
public class ShowOnlyDrawer : PropertyDrawer
{
    public override void OnGUI(Rect position, SerializedProperty prop, GUIContent label)
    {
        string valueStr;

        switch (prop.propertyType)
        {
            case SerializedPropertyType.Integer:
                valueStr = prop.intValue.ToString();
                break;
            case SerializedPropertyType.Boolean:
                valueStr = prop.boolValue.ToString();
                break;
            case SerializedPropertyType.Float:
                valueStr = prop.floatValue.ToString("0.00000");
                break;
            case SerializedPropertyType.String:
                valueStr = prop.stringValue;
                break;
            default:
                if (prop.objectReferenceValue)
                    valueStr = prop.objectReferenceValue.name;
                else
                    valueStr = "Not Supported!";
                break;
        }

        EditorGUI.LabelField(position, label.text, valueStr);
    }
}

You still need to setup for each Type that you want it to show, as of right now it doesn’t have much but some value types.

3

This is a complex class and I need to display its full inspector, but PropertyDrawers only seem to work with non-layout GUI. I don’t know any way to use GUILayout-based code inside it, like DrawDefaultInspector and OnInspectorGUI…