Dynamically Generate Plane Mesh in App from Vertices

Hi,

I am trying to generate a plane mesh in the app from 4 user defined vertices. This is for a hololens application, and I am getting the vertices from the cursor position. I have the following script attached to an empty game object with a material, a mesh filter, and a mesh renderer component. currently my application recognizes the 4 vertices inputted by the user, but no visual mesh seems to be created. Can anyone please tell me what I need to do differently? Thanks.

using UnityEngine; using System.Collections; using System.Collections.Generic;

public class EditPlane : MonoBehaviour {

 public TempStateManager stateManager;
 public TextMesh debug;
 private List<Vector3> vertexHolder;
 private Vector3 firstVertex;
 public GameObject cursor;
 private int input;
 // Use this for initialization
 void Start() {
     vertexHolder = new List<Vector3>();
     input = 0;
 }


 void OnSelect()
 {
     if (stateManager.state == "setVertices")
     {

         if (input < 4)
         {
             if (input == 0)//first time
             {
                 firstVertex = cursor.transform.position;//save first y position
                 //add first vertex (vertex 0)
                 vertexHolder.Add(firstVertex);
                 Debug.Log("added first vertex");
                 debug.text = "added first vertex";
             }
             else 
             {
                 Vector3 newVertex = new Vector3(cursor.transform.position.x, firstVertex.y, cursor.transform.position.z);
                 //add vertices 1, 2, and 3
                 vertexHolder.Add(newVertex);
                 Debug.Log("added subsequent vertex");
                 debug.text = "added subsequent vertex";
                 if(input ==3)//last input
                 {
                     debug.text = "last vertex";

                     //triangles
                     int[] tri = new int[6];
                     tri[0] = 0;
                     tri[1] = 2;
                     tri[2] = 1;

                     tri[3] = 2;
                     tri[4] = 3;
                     tri[5] = 1;

                     //normals
                     Vector3[] normals = new Vector3[4];
                     normals[0] = Vector3.up;
                     normals[1] = Vector3.up;
                     normals[2] = Vector3.up;
                     normals[3] = Vector3.up;

                     Mesh mesh = new Mesh();
                     GetComponent<MeshFilter>().mesh = mesh;
                     mesh.SetVertices(vertexHolder);
                     mesh.triangles = tri;
                     mesh.normals = normals;
                     debug.text = "set mesh";
                 }
             }
             input++;
         }
     }

 }

}