Z Fighting Problem

Make the camera's near clip plane as big as possible, and the far clip plane as small as possible, so the depth buffer's precision isn't wasted.

Here is a video about unity depth shader workarounds:

http://www.burgzergarcade.com/tutorials/game-engines/unity3d/unity-ios-shaderlab-tutorial-10-1-z-fighting

also his tutorial 6.2 and 6.3 are all about depth...

and this unity resource: http://unity3d.com/support/documentation/Components/SL-CullAndDepth.html

Here is a Ton of info about it with 3 solutions:

http://software.intel.com/en-us/articles/alternatives-to-using-z-bias-to-fix-z-fighting-issues/

I have ended with a custom-non-optimal-solution that at least works for me. I add a "ZFighter" component to any GameObject which I want to get a little bit distanced from a back object/wall. This separation is calculated according to Camera distance.

 using UnityEngine;
 using System.Collections;
 
 public class ZFighter : MonoBehaviour {
 
     // Use this for initialization
     private Vector3 lastLocalPosition;
     private Vector3 lastCamPos;
     private Vector3 lastPos;
 
        void Start () {
         lastLocalPosition = transform.localPosition;
         lastPos = transform.position;
         lastCamPos = Camera.main.transform.position - Vector3.up; // just to force update on first frame
     }
     
      void Update () {
         Vector3 camPos = Camera.main.transform.position;
         if (camPos != lastCamPos || transform.position != lastPos) {
             lastCamPos = camPos;
             transform.localPosition = lastLocalPosition + (camPos - transform.position) * 0.01f;
             lastPos = transform.position;
         }
     }
 }