missed lightPositionZ update

Author: erictheise

lesson13/index.html

@@ -685,7 +685,7 @@ <h2>Point light:</h2>
             <td><b>Location:</b>
             <td>X: <input type="text" id="lightPositionX" value="0.0" />
             <td>Y: <input type="text" id="lightPositionY" value="0.0" />
-            <td>Z: <input type="text" id="lightPositionZ" value="-5.0" />
+            <td>Z: <input type="text" id="lightPositionZ" value="-3.9" />
         </tr>
         <tr>
             <td><b>Colour:</b>