title: In 3d graphics, what is camera or eye space?
body: <p>I'm trying to learn 3d graphics programming through "Learning Modern 3D Graphics Programming" by Jason L. McKesson.</p>
  
  <p>I have not really looked at other guides, but this guide seems to emphasize the theory and mathematics behind 3d graphics. Right now, I am stuck on this page:</p>
  
  <p><a href="http://www.arcsynthesis.org/gltut/Positioning/Tut04%20Perspective%20Projection.html">http://www.arcsynthesis.org/gltut/Positioning/Tut04%20Perspective%20Projection.html</a></p>
  
  <p>I am not exactly sure what he means by camera space, and why it is necessary to project a 3d world onto a 2d surface. This question is kind of vague, so instead of a full explanation, links that might give me a different way of explaining these concepts would be appreciated as well.</p>