Runtime Mesh Generation - Messed up!

I have tried diffrent solutions for the past 3 days.
Any ideas ?

Code (CSharp):

1. for (int j = 0, k = 0; j < verticesArray.Length; k++)
2.                 {
3.                   ;
4.                     GeoWithCords data = EntityManager.GetComponentData<GeoWithCords>(iterator[k]);
5.  
6.                     Vector2 v2a = new Vector2(data.cords0.x, data.cords0.y);
7.                     Vector2 v2b = new Vector2(data.cords1.x, data.cords0.y);
8.                     Vector2 v2c = new Vector2(data.cords2.x, data.cords0.y);
9.                     Vector2 v2d = new Vector2(data.cords3.x, data.cords0.y);
10.  
11.                     verticesArray[j] = p.transform.InverseTransformPoint(new Vector3(layerDepth, v2a.y, v2a.x));
12.                     verticesArray[j + 1] = p.transform.InverseTransformPoint(new Vector3(layerDepth, v2b.y, v2b.x));
13.                     verticesArray[j + 2] = p.transform.InverseTransformPoint(new Vector3(layerDepth, v2c.y, v2c.x));
14.                     verticesArray[j + 3] = p.transform.InverseTransformPoint(new Vector3(layerDepth, v2d.y, v2d.x));
15.                     j += 4;
16.                  
17.  
18.                 }
19.            
20.                 for (int v = 0; v < iteratorLength; v++)
21.                 {
22.                                      
23.                     triangles[t] = v;
24.                     triangles[t + 1] = 2 + v;
25.                     triangles[t + 2] = 1 + v;
26.  
27.                     triangles[t + 3] = 3 + v;
28.                     triangles[t + 4] = 1 + v;  
29.                     triangles[t + 5] = 2 + v;
30.  
31.                    
32.                     t += 6;
33.  
34.                 }
35.  
36.                 mesh.vertices = verticesArray;
37.                 mesh.triangles = triangles;
38.                 mesh.RecalculateNormals();

 

It is unclear what you are trying to do. Can you simplify it down to a single triangle (three vertices and three integer offsets) and get that to go through correctly?

 

Iam trying to combine all the vertices and triangels into one mesh.

If i draw every triangle as a seperate mesh it works. But it is slow :/

 

Why not this?

https://docs.unity3d.com/ScriptReference/Mesh.CombineMeshes.html