#### Having trouble generating a mesh in unity

I have been trying to generate a mesh using the code below, and have been successful generating a mesh with width and length of one, but any more and I get an error in the console that says "Failed setting triangles. Some indices are referencing out of bounds vertices. IndexCount: 24, VertexCount: 9
UnityEngine.Mesh:set_triangles (int[])"
I have done all the math of calculating the triangles on paper, and all of the values are within the length of the vertices array, going from 0 to 8. I don’t have any clue what I am doing wrong, or why this error message is getting thrown, so any help would be greatly appreciated.

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

public class MeshGenerator : MonoBehaviour
{
Mesh mesh;
Vector3[] vertices;
int[] triangles;

public Mesh GenerateMesh(int mapWidth, int mapHeight)
{
mesh = new Mesh();
vertices = new Vector3[(mapHeight + 1) * (mapWidth + 1)];
triangles = new int[6 * (mapHeight * mapWidth)];
int index = 0;
for (int x = 0; x <= mapHeight; x++)
{
for (int y = 0; y <= mapWidth; y++)
{
vertices[index] = new Vector3(x, 0, y);
index += 1;
}
}
int z = 0;
for (int i = 0; i <= triangles.Length - 1; i += 6)
{
Debug.Log(i);
if (z == mapWidth)
{
triangles[i] = i + 1;
triangles[i + 1] = i + 2;
triangles[i + 2] = i + mapWidth + 3;
triangles[i + 3] = i + 1;
triangles[i + 4] = i + mapWidth + 3;
triangles[i + 5] = i + mapWidth + 2;
z = 0;
}
else
{
triangles[i] = i;
triangles[i + 1] = i + 1;
triangles[i + 2] = i + mapWidth + 2;
triangles[i + 3] = i;
triangles[i + 4] = i + mapWidth + 2;
triangles[i + 5] = i + mapWidth + 1;
z++;
}
}
mesh.vertices = vertices;
mesh.triangles = triangles;
mesh.RecalculateNormals();
return mesh;
}
}

``````

Source: Visual Studio Questions