**Function: creating a mesh data for god's sake

DumbMesh.cs

using UnityEngine;

[RequireComponent(typeof(MeshFilter))]
[ExecuteInEditMode]
public class DumbMesh : MonoBehaviour
{
void Start()
    {
        GenerateMesh();
    }

    void GenerateMesh()
    {
        Mesh mesh = GetComponent<MeshFilter>().sharedMesh;
        if (mesh == null)
        {
            mesh = new Mesh();
            GetComponent<MeshFilter>().sharedMesh = mesh;
        }
        mesh.Clear();
        mesh.vertices = new Vector3[]
        {
            new Vector3(-1,-1,0),
            new Vector3(1,-1,0),
            new Vector3(1,1,0),
            new Vector3(-1,1,0),
        };

        mesh.triangles = new int[]
        {
            2,1,0,
            3,2,0
        };

        mesh.uv = new Vector2[]
        {
            new Vector3(0,0,0),
            new Vector3(1,0,0),
            new Vector3(1,1,0),
            new Vector3(0,1,0),
        };
    }
}