Access a material on object with more than one material within scene view

I'm trying to create a simple script for applying materials on models in the scene view. If I click on a prefab instance in the scene view I want to override the material with a new material.

The script below works fine on objects with only one material applied but on objects and prefabs with more than one material it only assigns to the first one.

How do you obtain the right material?

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEditor;
5.  
6. public class PaintMaterial : EditorWindow
7. {
8.     [SerializeField] private Material material;
9.     [SerializeField] public bool canPaint = false;
10.  
11.     [MenuItem("Tools/Paint Material")]
12.     static void CreateReplaceWithPrefab()
13.     {
14.         EditorWindow.GetWindow<PaintMaterial>();
15.     }
16.  
17.     private void OnEnable()
18.     {
19.         if (!Application.isEditor)
20.         {
21.             Destroy(this);
22.         }
23.         SceneView.onSceneGUIDelegate += OnScene;
24.     }
25.  
26.     void OnScene(SceneView scene)
27.     {
28.         Event e = Event.current;
29.  
30.         if (e.type == EventType.MouseDown && canPaint )
31.         {  
32.             //Debug.Log("Left Mouse was pressed");
33.             Vector3 mousePos = e.mousePosition;
34.             float ppp = EditorGUIUtility.pixelsPerPoint;
35.             mousePos.y = scene.camera.pixelHeight - mousePos.y * ppp;
36.             mousePos.x *= ppp;
37.  
38.             Ray ray = scene.camera.ScreenPointToRay(mousePos);
39.             RaycastHit hit;
40.  
41.             if (Physics.Raycast(ray, out hit))
42.             {
43.                 Debug.Log("Clicked point " + hit.point);
44.                 //Debug.Log("Trianngle " + hit.triangleIndex.ToString());
45.                 //Debug.Log("gameobject= " + hit.transform.gameObject.name.ToString());
46.                 //Transform go = hit.collider.transform;
47.                 //Debug.Log("gameobject="+go.name.ToString());
48.  
49.                 Renderer renderer = hit.collider.GetComponent<Renderer>();
50.                 if ( renderer != null ) {
51.                     Material mat = renderer.sharedMaterial;
52.                     Debug.Log ("material = " + mat.name.ToString());
53.                    
54.                     //left
55.                     if ( e.button == 0  ) {
56.                         if ( material != null ) {
57.                             renderer.sharedMaterial = material; //this needs to change to locate the right material
58.                             Repaint(); //refresh UI
59.                         }
60.                     }
61.                     //right
62.                     if ( e.button == 1 ) {
63.                         material = renderer.sharedMaterial;
64.                         Repaint(); //refresh UI
65.                     }
66.                 }
67.             }
68.         }
69.     }
70.  
71.     private void OnGUI()
72.     {
73.         material = (Material)EditorGUILayout.ObjectField("Material", material, typeof(Material), false);
74.         canPaint = EditorGUILayout.Toggle("Can Paint ", canPaint);
75.     }
76. }

 

To access multiple,

Material[] mats = renderer.sharedMaterials;

, to set the 2nd material of 2,

renderer.sharedMaterials[1] = material;

 

Thanks for this, although the main problem I think I'm having is that the hit.collider method isn't always identifying the right material under the mouse click. Sometimes it returns a material that is hidden from view.