Changing MeshRenderer Materials at Runtime

I have changed MeshRenderer materials before, but never on an object with multiple material ID's, and I am having a little trouble achieving this.

I assumed it was as straight-forward as assigning to an array with an int, but that doesn't appear to be working.

The script is designed to toggle a light and an object's material on and off, simulating a bulb switching on and off in a flickering manner.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. [System.Serializable]
6. public class LightFlickerArray
7. {
8.     public MeshRenderer lightObject;
9.     public int material = 0;
10. }
11.  
12. public class LightFlicker : MonoBehaviour
13. {
14.     public GameObject light;
15.     public Material onMaterial;
16.     public Material offMaterial;
17.     [SerializeField]
18.     public LightFlickerArray[] lightObjects;
19.  
20.     void Update()
21.     {
22.         if (Random.value > 0.9)
23.         {
24.             if (light.activeSelf == true)
25.             {
26.                 light.SetActive(false);
27.                 foreach(LightFlickerArray lfr in lightObjects)
28.                 {
29.                     lfr.lightObject.materials[lfr.material] = offMaterial;
30.                 }
31.             }
32.             else
33.             {
34.                 light.SetActive(true);
35.                 foreach (LightFlickerArray lfr in lightObjects)
36.                 {
37.                     lfr.lightObject.materials[lfr.material] = onMaterial;
38.                 }
39.             }
40.         }
41.     }
42. }

 

From the docs:

 

Seems like a needlessly complicated system, but thanks, it's working now