title: Efficient 3D block rendering with Libgdx
body: <p>To start with,I am pretty new to 3D programming and libgdx.
  I looked at a few tutorials and I already render the scene I want. I have some 1x1x1 blocks, created with <code>ModelBuilder.createRect()</code> for every visible face, so if another block covers a face of this block, there is no rect created for this block. Also the top and bottom rect is not needed, as I can never see them (except for the floor). So I thought, that this is pretty efficient. I also have <code>Backface culling</code> enabled and I do <code>Viewfrustum culling</code>. However, if I look in a direction, where many blocks are in my viewfrustum the FPS go down to 15-20. This is still okay for me, as my laptop is over  5 years old and its performance is not the best, but <a href="https://stackoverflow.com/a/22106958/3182091">this answer</a> made me think.</p>
  
  <p>"ModelBuilder is used for debug only". Okay, but how should i then create my boxes? Why should i create a <code>Model</code> in a Modeling app (like Blender), for simple squares? By doing this i couldn't even cull the faces, which are occupied by other blocks.
  So my question is:
  How can i create and render those boxes the most efficient way?</p>