title: Draw points in Metal
body: <p>I use drawIndexedPrimitives function to draw points in Metal, but I don't know where should I adjust the point size. In OpenGL ES, I can adjust the point size in the shader: gl_PointSize = 10.0f; How does this work in Metal? </p>
  
  <p>By the way, for draw points from a file, I have a las file(3d point cloud data: a sequential binary format used to store data from sensors and as intermediate processing storage by some applications), and I want to import it to Xcode and render those points using Metal for iOS, anyone knows how to implement with the las file using Metal? Should I transform it to OBJ or PLY before importing it?</p>
  
  <p>Draw points function(swift):</p>
  
  <pre><code>commandEncoder.drawIndexedPrimitives(.Point,
                                       indexCount:indexCount,
                                       indexType:.UInt16,
                                       indexBuffer:indexBuffer,
                                       indexBufferOffset: 0)
  </code></pre>