CombineMeshes() Not Working Properly?

Hello Everyone,

I'm trying to combine three cubes into one mesh and keep them as individual submeshes to preserve their individual material's. However, when I combine the three cubes under the parent object, they all use the parent's material, even though I've set mergeSubMeshes to false.

Thanks for the help!

 using UnityEngine;
 using System.Collections;
 
 [RequireComponent(typeof(MeshFilter))]
 [RequireComponent(typeof(MeshRenderer))]
 public class Test1 : MonoBehaviour {
     void Start() {
         MeshFilter[] meshFilters = GetComponentsInChildren<MeshFilter>() ;
         CombineInstance[] combine = new CombineInstance[meshFilters.Length];
         int i = 0;
         while (i < meshFilters.Length) {
             combine[i].mesh = meshFilters[i].sharedMesh;
             combine[i].transform = meshFilters[i].transform.localToWorldMatrix;
             meshFilters[i].gameObject.active = false;
             i++;
         }
         transform.GetComponent<MeshFilter>().mesh = new Mesh();
         transform.GetComponent<MeshFilter>().mesh.CombineMeshes(combine,false, false);
         transform.gameObject.active = true;
     }
 }