Problem with generating a mesh behind an Object

Hello,
I have a problem with generating a wall behind a moving object by scripting it.
The Errors are here:

The Code is as following in C#

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3. using System.Collections.Generic;
4.  
5. [RequireComponent(typeof(MeshFilter), typeof(MeshRenderer))]
6.  
7. public class WallScript : MonoBehaviour {
8.  
9.  
10.     public GameObject Wall;
11.     public float height = 1;
12.     private int z = 1;
13.     private int i = 0;
14.     private bool newcalc = false;
15.     private Mesh mesh;
16.  
17.  
18.     List <Vector3> vList = new List<Vector3>();
19.     List <int>  triList = new List <int>();
20.     List <Vector3> normalsList = new List<Vector3>();
21.     List <Vector2> uvList = new List <Vector2>();
22.  
23.  
24.  
25. // Use this for initialization
26. void Start () {
27.  
28. GetComponent<MeshFilter>().mesh = mesh = new Mesh();
29.  
30.     vList.Add(new Vector3(0,0,0));
31.     vList.Add(new Vector3(0,height,0));
32.     vList.Add(new Vector3(0,0,0));
33.     vList.Add(new Vector3(0,height,0));
34.  
35. Debug.Log("Started");
36.  
37.  
38.     mesh.vertices = vList.ToArray();
39.  
40.  
41. }
42.  
43. // Update is called once per frame
44. void FixedUpdate () {
45.  
46. if(vList[z-1] != Wall.transform.position + new Vector3(0,0,0)
47.     || vList[z] != Wall.transform.position + new Vector3(0,height,0))
48. {
49.     vList.Add(Wall.transform.position + new Vector3(0,0,0));
50.     vList.Add(Wall.transform.position + new Vector3(0,height,0));
51.     vList.Add(Wall.transform.position + new Vector3(0,0,0));
52.     vList.Add(Wall.transform.position + new Vector3(0,height,0));
53.  
54.     mesh.vertices = vList.ToArray();
55.     z += 4;
56.     newcalc = true;
57.  
58.     Debug.Log("Noticed Vertices are not the same");
59.  
60. }
61.  
62. if(newcalc == true)
63. {
64.     triList.Add(i+0);
65.     triList.Add(i+1);
66.     triList.Add(i+4);
67.  
68.     triList.Add(i+1);
69.     triList.Add(i+5);
70.     triList.Add(i+4);
71.  
72.     triList.Add(i+6);
73.     triList.Add(i+3);
74.     triList.Add(i+2);
75.  
76.     triList.Add(i+6);
77.     triList.Add(i+7);
78.     triList.Add(i+3);
79.  
80.     mesh.triangles = triList.ToArray();
81.     i = i+8;
82.     newcalc = false;
83.  
84.  
85.     normalsList.Add(new Vector3(0,0,1));
86.     normalsList.Add(new Vector3(0,0,1));
87.     normalsList.Add(new Vector3(0,0,1));
88.     normalsList.Add(new Vector3(0,0,1));
89.  
90.     normalsList.Add(new Vector3(0,0,1));
91.     normalsList.Add(new Vector3(0,0,1));
92.     normalsList.Add(new Vector3(0,0,1));
93.     normalsList.Add(new Vector3(0,0,1));
94.  
95.     mesh.normals = normalsList.ToArray();
96. }
97. }
98. }

I hope somebody can help me figure this out.
Thanks in advance.

 

Code (csharp):

1.  
2. vList.Add(Wall.transform.position + new Vector3(0,0,0));
3. vList.Add(Wall.transform.position + new Vector3(0,height,0));
4. vList.Add(Wall.transform.position + new Vector3(0,0,0));
5. vList.Add(Wall.transform.position + new Vector3(0,height,0));
6.  

so vertex indexes 0, 1, 2, 3

Code (csharp):

1.  
2. triList.Add(i+0);
3. triList.Add(i+1);
4. triList.Add(i+4);
5.  

build a triangle from 0, 1, 4 ... err, where did 4 come from?

 

In the Start function I generate my first 4 Vertices at line 30.

Code (CSharp):

1. void Start () {
2. GetComponent<MeshFilter>().mesh = mesh = new Mesh();
3.     vList.Add(new Vector3(0,0,0));
4.     vList.Add(new Vector3(0,height,0));
5.     vList.Add(new Vector3(0,0,0));
6.     vList.Add(new Vector3(0,height,0));
7. Debug.Log("Started");
8.     mesh.vertices = vList.ToArray();
9. }

Then in the FixedUpdate I generate 4 more at line 49.

Code (CSharp):

1. if(vList[z-1] != Wall.transform.position + new Vector3(0,0,0)
2.     || vList[z] != Wall.transform.position + new Vector3(0,height,0))
3. {
4.     vList.Add(Wall.transform.position + new Vector3(0,0,0));
5.     vList.Add(Wall.transform.position + new Vector3(0,height,0));
6.     vList.Add(Wall.transform.position + new Vector3(0,0,0));
7.     vList.Add(Wall.transform.position + new Vector3(0,height,0));
8.     mesh.vertices = vList.ToArray();
9.     z += 4;
10.     newcalc = true;
11.     Debug.Log("Noticed Vertices are not the same");
12. }

So there I have 8 Vertices.
Does that explain your question or am I missing something?

 

start only gets called once, so in the first instance of i you have 8 vertices, next iteration of i you have 8+4 vertices, and try to access 8+8

 

Thanks! That solved the problem!