EditorWindow multiselect material setting fail

Graphics Shaders & Materials
1

I’ve run into a problem setting the sharedMaterial on renderers and I’m stumped. I’d really appreciate a sanity check. A simplified version of what’s happening is presented below.

First, I have an EditorWindow script that iterates over some renderers for the selected game objects and replaces their sharedMaterial array:

using UnityEngine;
using UnityEditor;
using System;
using System.Collections.Generic;
using System.IO;

public class DuplicateMaterials : EditorWindow
{
    [MenuItem("Window/DuplicateMaterials")]
   
    public static void ShowWindow()
    {
        EditorWindow.GetWindow(typeof(DuplicateMaterials));
    }
   
    public void OnGUI()
    {
        if (GUILayout.Button("Duplicate materials"))
            Execute();
    }
   
    private void Execute()
    {
        Transform[] transforms = Selection.GetTransforms(SelectionMode.TopLevel|SelectionMode.Editable|SelectionMode.ExcludePrefab);
       
        if (transforms == null || transforms.Length == 0)
            return;
       
        Shader defaultShader = Shader.Find("Sprites/Default");
       
        foreach (Transform transform in transforms)
        {
            GameObject gameObject = transform.gameObject;
            SpriteRenderer[] renderers = gameObject.GetComponentsInChildren<SpriteRenderer>();
            for (int i=0; i<renderers.Length; ++i)
            {
                SpriteRenderer renderer = renderers[i];
               
                string assetPath = "Assets/stub " + gameObject.name + ".mat";
               
                Material material = new Material(defaultShader);
               
                AssetDatabase.CreateAsset(material, assetPath);
                AssetDatabase.Refresh();
                AssetDatabase.SaveAssets();
               
                Material[] stub = renderer.sharedMaterials;
                stub[0] = AssetDatabase.LoadAssetAtPath<Material>(assetPath);
                renderer.sharedMaterials = stub;
               
                EditorUtility.SetDirty(renderer);
            }
           
            EditorUtility.SetDirty(gameObject);
        }
    }
}

The code works when selecting single game objects. When selecting multiple objects, however, the materials set in this fashion are not sticky - unselecting and doing a multiselect of the game objects in the Hierarchy will end up replacing all the materials with one of the generated materials:

2279585--153043--materialReassign.png

I’d appreciate any insight any reader can offer, I’m out of ideas for the moment.

2

Looks like I got bitten by Unity Issue Tracker - Selecting multiple objects with sprite renderer overwrites all of their materials with first selected object one . Did not occur to me to try this out first :/.