How to make my character move endless?

o I'm working an endless runner game and i have created a script thats suppose to make the terrain move backwards but it doesnt work even i add the script to the terrain. The guys just runs with no movement. I must all note that im using a thirdperson controller as well as using this site as a guide: http://www.thegamecontriver.com/2014/06/subway-surfers-temple-run-like-game-set-ground-moving.htmlSo this is the script:

public class RunIllusion : MonoBehaviour {

 //Material texture offset rate
 
 float speed = .5f;
 
 //Offset the material texture at a constant rate
 void Update () {
     float offset = Time.time * speed;                             
     renderer.material.mainTextureOffset = new Vector2(0, -offset); 
 }

}