Creating a Pentahedron (a 5 sided shape) Mesh procedurally

I try to create a 5 sided shape mesh procedurally in a JS script, then i dragged and dropped it in the Main Camera so i can see it, here's the code:

 function Start() {
 
     var tmpobj: GameObject = new GameObject();
     
     tmpobj.AddComponent(MeshFilter);
     tmpobj.AddComponent(MeshRenderer);
     
     var verts: Vector3[] = new Vector3[5];
     var normals: Vector3[] = new Vector3[5];
     var uv: Vector2[] = new Vector2[5];
     var tri: int[] = new int[12]; //3 vertices * 4 triangles =12
    
     var mf: MeshFilter = GetComponent(MeshFilter);
    
    //vertices positioning of the points P1,P2,P3,P4,P5
     verts[0] = new Vector3(0, 0, 0); //P5
     verts[1] = new Vector3(-5, 0, -5); //P1
     verts[2] = new Vector3(-5, 0, 5); //P2
     verts[3] = new Vector3(5, 0, 5); //P3
     verts[4] = new Vector3(5, 0, -5); //P4
    
     for (i = 0; i < normals.Length; i++) {
         normals[i] = Vector3.up;
     }
    
     uv[0] = new Vector2(0, 0);
     uv[1] = new Vector2(1, 0);
     uv[2] = new Vector2(0, 1);
     uv[3] = new Vector2(1, 1);
     uv[4] = new Vector2(0, 0);
     
     //triangles (clockwise)
     tri[0] = 0;
     tri[1] = 1;
     tri[2] = 2;
    
     tri[3] = 0;
     tri[4] = 2;
     tri[5] = 3;
     
     tri[6] = 0;
     tri[7] = 3;
     tri[8] = 4;
    
     tri[9] = 0;
     tri[10] = 4;
     tri[11] = 1;
     
     var mesh: Mesh = new Mesh();
     mesh.name = "Roof_01";
     mesh.vertices = verts;
     mesh.triangles = tri;
     mesh.uv = uv;
     mesh.normals = normals;
     mesh.RecalculateNormals();
     mf.mesh = mesh;
     
     
 }

I don't know what i'm doing wrong and i can't see the mesh. The thing is it's my first time using Meshes by code and i'm not familiar with them yet. I get that exception:

"MissingComponentException: There is no 'MeshFilter' attached to the "Main Camera" game object, but a script is trying to access it. You probably need to add a MeshFilter to the game object "Main Camera". Or your script needs to check if the component is attached before using it. Roof.Start () (at Assets/Roof.js:79)"

Any idea why i can't see the Mesh? Thanks in advance.