title: Getting nearest focused object in opengl
body: <p>I'm making a minecraft-inspired game through Java LWJGL, which is heavy into development already. However, I am not quite sure what method I would use to pick/highlight the nearest block in the exact center of the player's view frustum.</p>
  
  <p>I am already storing frustum and positional data, which I could use.</p>
  
  <p>I had a vague idea about using raycasting, but this seems to be unrelated based on what people have done with raycasting.</p>
  
  <p>So which function or test would I use to determine this?</p>