Changing a material using Unity Editor Script

Questions & Answers
1

I have the following game object

MyGameObject
-MeshRenderer
----Materials:
----- Size: 1
----- Element 0: MyGameObjectMaterial

I want to change the gameobject material using a Unity Editor Script, my script looks similar to this

using UnityEngine;
using UnityEditor;
using System.Collections;

public class BuildingAutomator : EditorWindow
{
    public GameObject myGameObject;
	public Material myNewMaterial;
	
    // Add menu named "My Window" to the Window menu
    [MenuItem("Window/My Window")]
    static void Init()
    {
        // Get existing open window or if none, make a new one:
        BuildingAutomator window = (BuildingAutomator)EditorWindow.GetWindow(typeof(BuildingAutomator));
    }

    void OnGUI()
    {
        if(GUILayout.Button("Change material!"))
        {
            myGameObject.renderer.materials[0] = myNewMaterial; //<--- Error
        }
    }
}

But it throws the following error:

Instantiating material due to calling renderer.material during edit mode. This will leak materials into the scene. You most likely want to use renderer.sharedMaterial instead.
UnityEngine.Renderer:get_materials()

Any suggestions?

2

You most likely want to use renderer.sharedMaterial instead.

myGameObject.renderer.sharedMaterials[0] = myNewMaterial;