title: Xlib: extension "GLX" missing on display ":0"
body: <p>I'm trying to use Point Cloud Library with Ubuntu 12.04. However when I execute point cloud visualization program, I get the following error:</p>
  
  <p><code>
  Xlib:  extension "GLX" missing on display ":0".
  </code></p>
  
  <p>These are my system information:</p>
  
  <pre><code>$ glxinfo
  name of display: :0
  Xlib:  extension "GLX" missing on display ":0".
  Xlib:  extension "GLX" missing on display ":0".
  Xlib:  extension "GLX" missing on display ":0".
  Xlib:  extension "GLX" missing on display ":0".
  Xlib:  extension "GLX" missing on display ":0".
  Error: couldn't find RGB GLX visual or fbconfig
  
  Xlib:  extension "GLX" missing on display ":0".
  Xlib:  extension "GLX" missing on display ":0".
  Xlib:  extension "GLX" missing on display ":0".
  Xlib:  extension "GLX" missing on display ":0".
  Xlib:  extension "GLX" missing on display ":0".
  Xlib:  extension "GLX" missing on display ":0".
  Xlib:  extension "GLX" missing on display ":0".
  
  $ sudo lshw -C display
    *-display
         description: VGA compatible controller
         product: GF106M [GeForce GT 555M]
         vendor: NVIDIA Corporation
         physical id: 0
         bus info: pci@0000:01:00.0
         version: a1
         width: 64 bits
         clock: 33MHz
         capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
         configuration: driver=nvidia latency=0
         resources: irq:16 memory:f2000000-f3ffffff memory:d0000000-dfffffff memory:e0000000-e3ffffff ioport:d000(size=128) memory:f4000000-f407ffff
    *-display
         description: VGA compatible controller
         product: 2nd Generation Core Processor Family Integrated Graphics Controller
         vendor: Intel Corporation
         physical id: 2
         bus info: pci@0000:00:02.0
         version: 09
         width: 64 bits
         clock: 33MHz
         capabilities: msi pm vga_controller bus_master cap_list rom
         configuration: driver=i915 latency=0
         resources: irq:49 memory:f4400000-f47fffff memory:c0000000-cfffffff ioport:e000(size=64)
  </code></pre>
  
  <p>Because my laptop is with Nvidia Gt555m graphics card and optimus, I tried to install Bumblebee. But when I execute <code>apt-get install bumblebee</code>, my PC stops and turn into black screen.</p>
  
  <p>How can I solve this? Do I really have to install Bumblebee?</p>