title: How to allow the user to zoom and rotate 3D objects in Opengl and Visual C++
body: <p>I am new to opengl and visual c++. I have done a sample application which rotates 3D shapes in opengl. I want to allow the user to rotate and zoom the object. Please give me an example of how to do this.</p>
  
  <p>I have tried NeHe tutorial: <a href="http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=48" rel="nofollow">http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=48</a></p>
  
  <p>I can't understand the class structure in the example. Is there anysimple way to achieve this?</p>
  
  <p>I have found a library as well: <a href="http://www.nigels.com/glt/gltzpr/" rel="nofollow">http://www.nigels.com/glt/gltzpr/</a></p>
  
  <p>But still can't figure out how to do this.
  Please help me.</p>