title: Unlit shader issue with fog in Unity's Univeral Render Pipeline
body: <p><strong>Edit</strong><br>
  I figured out a tempoary fix for my initial question &quot;<em>how to disable this weird fog</em>&quot;: Disable the fog in the <strong>lighting pannel</strong> (genius, right ?)</p>
  <p>However, since I might need fog later, and it does not behave as I would expect, I still need to fix this issue.</p>
  <p><strong>Note</strong>: This only happens with exponential fog modes, not with linear.</p>
  <hr />
  <p>I'm having issues with unity's universal render pipeline: A light grey fog, whose strength depends on the camera heading (see <a href="https://drive.google.com/file/d/1XB2HTGpLoE2RdlRVU61nOznYLqS5Cq_J/view?usp=sharing" rel="nofollow noreferrer">video</a>)</p>
  <p><a href="https://i.stack.imgur.com/QYrA9.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/QYrA9.png" alt="Unity rendering issue" /></a>
  (see how the plane geometry affects the fog)</p>
  <p>The steps to reproduce are very simple (or just download the project <a href="https://drive.google.com/file/d/1pzbjabeCNomT2YrWETjr4jR13wNx-2Io/view?usp=sharing" rel="nofollow noreferrer">here</a>):</p>
  <ul>
  <li>Create a universal render pipeline project</li>
  <li>Delete the &quot;example assets&quot; from the scene</li>
  <li>Create a floor with a quad (create quad, rotate, scale)</li>
  <li>Create a new material
  <ul>
  <li>Shader: URP / unlit</li>
  <li>Base map: black</li>
  </ul>
  </li>
  </ul>
  <p>That's it.
  Rotate around, see how the &quot;unlit&quot; plane is actually affected by a fog whose strength depends on the heading of the camera</p>
  <ul>
  <li>Rotating the quad has the same effect as rotating the camera.</li>
  <li>Rotating the directionnal light has no effect (except on the skybox)</li>
  <li>Removing the Directionnal light has no effect (except on the skybox)</li>
  <li>Removing the Post processing volume makes the &quot;fog&quot; stronger in all directions so the camera heading effect is less noticeable but still there</li>
  <li>This happens in game mode as well as in the editor</li>
  <li>Getting close to the ground makes the fog lighter</li>
  <li>the camera position has an impact as well (this is more visible when testing with a plane rather than a quad)</li>
  </ul>
  <p>system info:</p>
  <ul>
  <li>tested on unity versions: 2019.4.18f1, 2019.4.20f1 (LTS), 2020.2.1f1</li>
  <li>Windows 10 Home 19042.804</li>
  </ul>
  <p>Is it possible this is a bug in the URP/unlit shader ?</p>
  <p>Thanks for any help!</p>