DrawMeshNow GUI Ortho

How do I draw ie a GUI/Texture in ortho (screen) mode
I must say the documentation on this subject/object is very poor/none.

Matrix4x4.Ortho
static function Ortho (left : float, right : float, bottom : float, top : float, zNear : float, zFar : float) : Matrix4x4
Description

Creates an orthogonal projection matrix.

The returned matrix is such that views left to right, bottom to top area, with zNear and zFar depth clipping planes.

  • What values do I use for left, right, top, bottom?
  • In what event/method do I actual call drawmeshnow?

In all my attempts I got either nothing or the object drawn in 3d
I tried

float left = 0f;
float right = Screen.width;
float bottom = 0f;
float top = Screen.height;

Matrix4x4 matrix = Matrix4x4.Ortho(left, right, bottom, top, Camera.current.near, Camera.current.far);

Graphics.DrawMeshNow(mesh, matrix);

GL.PushMatrix();
GL.LoadIdentity(); // With and without LoadIdentity
GL.LoadPixelMatrix();

// I tried using gui matrix
Graphics.DrawMeshNow(mesh, GUI.matrix);

// I tried using identity matrix
Graphics.DrawMeshNow(mesh, Matrix4x4.identity);

GL.PopMatrix();

GL.PushMatrix();
GL.LoadIdentity(); // With and without LoadIdentity
GL.LoadPixelMatrix(0, Screen.width, 0, Screen.height);

// I tried using gui matrix
Graphics.DrawMeshNow(mesh, GUI.matrix);

// I tried using identity matrix
Graphics.DrawMeshNow(mesh, Matrix4x4.identity);

GL.PopMatrix();

Camera.main.orthographic = true;

// I tried using gui matrix
Graphics.DrawMeshNow(mesh, GUI.matrix);

// I tried using identity matrix
Graphics.DrawMeshNow(mesh, Matrix4x4.identity);

Camera.main.orthographic = false;

Camera.current.orthographic = true;

// I tried using gui matrix
Graphics.DrawMeshNow(mesh, GUI.matrix);

// I tried using identity matrix
Graphics.DrawMeshNow(mesh, Matrix4x4.identity);

Camera.current.orthographic = false;

Anyone?

Not even any support from Unity?