 }
  to { 
    background-position-x: -200px;
  }
}
            </code></pre>
          </section>
          <section>
            <iframe width="100%" height="600" data-src="/ch8.html">
            </iframe>
          </section>


          <!-- Lighting -->
          <section>
            <h1>Lighting</h1>
          </section>
          <section>
            <img src="/images/slides/lighting.png" style="float:right; max-width:25%" />
            <h2 style="display: block;">Lightmapping</h2>
            <u