title: What's the header file of gluLookAt in Qt?
body: <p>I got some code for using OpenGL in Qt. And when I run it I got error as below:</p>
  
  <pre><code>C:\Users\Administrator\Desktop\NeHe6\NeHe6-build-desktop-Qt_4_8_1_for_Desktop_-_MinGW__Qt_SDK__Debug\..\NeHe6\nehewidget.cpp:54: error: 'gluLookAt' was not declared in this scope
  </code></pre>
  
  <p>It seems the header is missing. And the current headers are:</p>
  
  <pre><code>#include "nehewidget.h"
  #include &lt;QtGui&gt;
  #include &lt;qtopengl\QtOpenGL&gt;
  </code></pre>
  
  <p>And "nehewidget.h" contains below headers:</p>
  
  <pre><code>#include &lt;qtopengl\QGLWidget&gt;
  #include &lt;QTimer&gt;
  </code></pre>
  
  <p>Could anyone tell me what is the missing header?</p>