Below is a new video that looks into the how some of the special effects were done for the Battle of the Five Armies sequence and Smaug the Dragon. Sadly the movie didn't get a Best Visual Effects Oscar nomination it deserved with the slot going to the less deserving Interstellar.

Behinds the Scenes of the Visual Effects for Five Armies Battle. There are any Behinds the Scenes of the Visual Effects for Five Armies Battle in here.