object rotation to another vector not changing

Hi again everyone sorry to repeat a question but im still stuck and pulling my hair out over this one

this script works but it doesnt update when the object holding the script rotates.

basically i what i need is when the player is behind the object i want one part of the texture, to the left of the player show another part, in front of player another part etc etc

now as i said this script does work if the object stays facing one direction but the object will be moving and rotating so i need the back to always be at his back etc any help or more efficient way of doing this much appreciated

 function Update () 
 {
     var toTarget = (referenceCamera.transform.position - transform.position).normalized;

     if(toTarget.x > SpriteAnglesMin[0].x && toTarget.x < SpriteAnglesMax[0].x && toTarget.z  > 0){
         ObjectMesh.renderer.material.SetTextureOffset("_MainTex", Vector2(TextureCoordsX[0],0));
     }

     if(toTarget.x > SpriteAnglesMin[0].x && toTarget.x < SpriteAnglesMax[0].x && toTarget.z  < 0) {
         ObjectMesh.renderer.material.SetTextureOffset("_MainTex", Vector2(TextureCoordsX[2],0));
             }
     if(toTarget.z > SpriteAnglesMin[0].z && toTarget.z < SpriteAnglesMax[0].z && toTarget.x  < 0){
         ObjectMesh.renderer.material.SetTextureOffset("_MainTex", Vector2(TextureCoordsX[1],0));
     }
     if(toTarget.z > SpriteAnglesMin[0].z && toTarget.z < SpriteAnglesMax[0].z && toTarget.x  > 0) {
         ObjectMesh.renderer.material.SetTextureOffset("_MainTex", Vector2(TextureCoordsX[3],0));
     }
 }