// Draws a line from the bottom right
// to the top left of the Screen
// Using GL.Vertex
var mat : Material;

function OnPostRender() {
if (!mat) {
Debug.LogError("Please Assign a material on the inspector");
return;
}
GL.PushMatrix();
mat.SetPass(0);
GL.LoadOrtho();
GL.Begin(GL.LINES);
GL.Vertex(Vector3(1,0,0));
GL.Vertex(Vector3(0,1,0));
GL.End();
GL.PopMatrix();
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
public Material mat;
void OnPostRender() {
if (!mat) {
Debug.LogError("Please Assign a material on the inspector");
return;
}
GL.PushMatrix();
mat.SetPass(0);
GL.LoadOrtho();
GL.Begin(GL.LINES);
GL.Vertex(new Vector3(1, 0, 0));
GL.Vertex(new Vector3(0, 1, 0));
GL.End();
GL.PopMatrix();
}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

public mat as Material

def OnPostRender():
if not mat:
Debug.LogError('Please Assign a material on the inspector')
return
GL.PushMatrix()
mat.SetPass(0)
GL.LoadOrtho()
GL.Begin(GL.LINES)
GL.Vertex(Vector3(1, 0, 0))
GL.Vertex(Vector3(0, 1, 0))
GL.End()
GL.PopMatrix()