How to override Model importer inspector.

I'm not sure if it is possible. But I really hope so.

Basically I want to add a checkbox to the inspector, that will determine whether or not to execute something on import.



I know I can write a script for OnPostprocessModel, but that would happen for every model I import. Which I don't want, just ones I specify.

...

My issue is, no matter how I try, I can't get a perfect import from blender to Unity where rotation and scale of parent/child objects or default. No matter the fact the I have corrected it in a blender. Maybe a blender/unity version issue. One option will have an ok scale, but bad rotation; the other will have an ok rotation but bad scale. Different models respond differently to export settings. I have used custom exporter addons. Blender is hell for this!

I wrote a custom script, but the problem is every time I change the asset's import settings, it gets reset.
Plus having my project on GitHub will also cause issues as the Library folder gets ignored.

Code (CSharp):

1. public class MeshScaleCorrector : MonoBehaviour
2. {
3.     [MenuItem("Mesh/Set Scale to 1")]
4.     static void SetScale()
5.     {
6.         Object selecteObject = Selection.activeObject;
7.         string objectPath = AssetDatabase.GetAssetPath(selecteObject);
8.  
9.         if (!File.Exists(objectPath)){
10.             Debug.Log($"Cannot find asset path for: {selecteObject.name}");
11.             return;
12.         }
13.  
14.         if (selecteObject.GetType() != typeof(GameObject)){
15.             Debug.Log($"{selecteObject.name} is not a type of GameObject");
16.             return;
17.         }
18.  
19.         ScaleObject(((GameObject)selecteObject).transform);
20.     }
21.  
22.     private static void ScaleObject(Transform obj)
23.     {
24.         obj.localScale = Vector3.one;
25.         foreach (Transform child in obj){
26.             ScaleObject(child);
27.         }
28.     }
29. }

I just want a way I can apply the above method, but only to objects of my choosing. Creating a scriptable object, then storing a reference seems like a possibility. But that is a bit hacky!

 

I realised I can add a custom editor to the window... But is it possible to keep unity's custom editor view, and just add something at the end?

Code (CSharp):

1. [CustomEditor(typeof(ModelImporter))]
2. public class ModelImporterEditor : Editor

 

Yeah, there's a "draw default inspector" call you can make... check the APIs for it.

 

Yea, there is. But that will remove any dynamic customizations setup by unity's custom editor. That's why I was wondering if it's possible to merge.

I don't think it is though, just thought it would be worth asking the questing. I think the only options is to have a reference to the ones I want in a scriptable object, then do a check when overriding the import function.

Or stop using Blender haha

 

I think it is... you either do your custom stuff, then call the draw default, or vice-versa... depending on how you want it to stack.

Perhaps I am not fully understanding what you are trying to do?

Perhaps I'm misunderstanding what you mean here:

"But that will remove any dynamic customizations setup by unity's custom editor."

 

For instance, in my Datasack project I have a custom inspector window that looks like:



This is the class that runs it:

https://github.com/kurtdekker/datas...cks/Assets/Datasack/Core/DatasackInspector.cs

.. just a few excerpted lines:

Code (csharp):

1.         public override void OnInspectorGUI()
2.         {
3.             Datasack ds = (Datasack)target;
4.  
5.             DrawDefaultInspector();
6.  
7.             EditorGUILayout.BeginVertical();
8.  
9.             if (GUILayout.Button( "CODEGEN"))
10.             {

 

Hey,


So I meant unity already has a CustomEditor for the ModelImporter class.


So making a new custom inspector, and drawing default would result in the below.
Losing everything unity has done, which is not really worth it in the long run.

If only Unity's ModelImporterEditor class was accessible, I could inherit and override on it, then call base drawings. Allowing me to put a checkbox at the very top before their editor work is drawn. I did extensive googling, looks like it was available at one point, but has long been removed.

 

Ah, I now understand... I hadn't tried it with an FBX importer importer override.

That is a bummer! Thank you for setting me straight.

 

I'm trying to isolate the AnimationClip Editor from the model importer but I can't manage to do so as well : /

It would be great if individual parts of the importer (Animation Events, Curves, Textures, etc) where available

 

I'm making an LOD tool at the moment and have had to do stuff like this a lot; it's totally doable and pretty easy. You just need to create and draw a separate editor, rather than extending a base class or drawing the default inspector.

Code (CSharp):

1. using UnityEngine;
2. using UnityEditor;
3. using System;
4.  
5. [CustomEditor(typeof(ModelImporter))]
6. public class ModelImporterEditor : Editor
7. {
8.     Editor defaultEditor;
9.  
10.     void OnEnable()
11.     {
12.         defaultEditor = Editor.CreateEditor(targets, Type.GetType("UnityEditor.ModelImporterEditor, UnityEditor"));
13.     }
14.  
15.     void OnDisable()
16.     {
17.         DestroyImmediate(defaultEditor);
18.     }
19.  
20.     public override void OnInspectorGUI()
21.     {
22.         serializedObject.Update();
23.  
24.         defaultEditor.OnInspectorGUI();
25.  
26.         if(GUILayout.Button("CREATE LODs"))
27.         {
28.             //Do the LOD creation
29.         }
30.  
31.         serializedObject.ApplyModifiedProperties();
32.     }
33. }

Unity's

DrawDefaultInspector

simply draws Unity's basic configuration for an editor and its serialized fields, and you can't extend your class from the original editor because it's not directly accessible in your codebase. It still exists, though, so you can access it by using

Type.GetType

.

Another useful application for this type of approach is if you're assigning a scriptable object to a public field. You can actually create and draw the inspector for that object inside the inspector you're working with, which offsets the main usability disadvantage that scriptable objects can introduce.

Most of the classes have a pretty intuitive naming convention that corresponds to "ClassNameEditor," but it can also be helpful to look up a few resources, like this Unity C# Reference project on GitHub.

 

There's also ways you can directly access certain internal classes by using Assemblies to place your class inside of an existing assembly; I've done this to directly access some of the internal material editor code in the URP/HDRP. I haven't tried it in this case, but there's definitely fancier options if you want to really dig into it.

 

I tried this, but when inheriting from Editor I don't get the Apply and Revert buttons with that method (defaultEditor.OnInspectorGUI() does not seem to draw them).

If I inherit from AssetImporterEditor instead, I can add the Apply Revert buttons using ApplyRevertGUI(); but I'm getting a lot of errors then about

Code (CSharp):

1. The previous instance of UnityEditor.ModelImporterEditor has not been disposed correctly. Make sure you are calling base.OnDisable() in your AssetImporterEditor implementation.
2. UnityEditor.Editor:CreateEditor (UnityEngine.Object[],System.Type)

Did you find a clean solution to this?

 

EDIT: Noted that this does produce the same errors about disposing of the editor that you mentioned, despite displaying correctly. I have been investigating to see if I can get this to work with both reflection and non-reflection methods, but I also think I need to read up on what would cause an editor to not be properly disposed when all signs point to it working as intended.

Hey, I actually noticed this after I posted but didn't find a solution for it and forgot to check back on this page. Your implementation of AssetImporterEditor actually allowed me to find the solution though, so thank you for that!

Here's what I did:

Code (CSharp):

1. using UnityEngine;
2. using UnityEditor;
3. using System;
4. using UnityEditor.Experimental.AssetImporters;
5.  
6.  
7. [CustomEditor(typeof(ModelImporter))]
8. public class ModelImporterEditor : AssetImporterEditor
9. {
10.     Editor defaultEditor;
11.  
12.     public override void OnEnable()
13.     {
14.         defaultEditor = Editor.CreateEditor(targets, Type.GetType("UnityEditor.ModelImporterEditor, UnityEditor"));
15.  
16.         base.OnEnable();
17.     }
18.  
19.     public override void OnDisable()
20.     {
21.         DestroyImmediate(defaultEditor);
22.         base.OnDisable();
23.     }
24.  
25.     public override void OnInspectorGUI()
26.     {
27.         serializedObject.Update();
28.  
29.         defaultEditor.OnInspectorGUI();
30.  
31.         ApplyRevertGUI();
32.  
33.         if (GUILayout.Button("CREATE LODs"))
34.         {
35.             //Do the LOD creation
36.         }
37.  
38.         serializedObject.ApplyModifiedProperties();
39.     }
40. }

I just implemented this, so I'm not sure if there are any unexpected issues with it that could crop up, but it does seem like it does what we were both intending.

 

This still works (not) but it looks like defaultEditor.OnInspectorGUI and ApplyRevertGUI both draw Asset PostProcessor Info lists.
Does anyone know how to draw this only once?

Apart from that:
The previous instance of ModelImporterEditor has not been disposed correctly. Make sure you are calling base.OnDisable() in your AssetImporterEditor implementation.
UnityEditor.AssetImporters.AssetImporterEditor:InternalSetTargets (UnityEngine.Object[])

And it no longer checks if properties have been changed when deselecting the asset :-/

 

+1 for @fleity
Is there a way to make it work again. Or maybe another approach would be better.

 

Just in case for future reference, here is another thread with a very similar approach, but slightly different, using reflection: https://forum.unity.com/threads/how-to-add-custom-editor-to-assetpostprocessor.1161476/