How have the explosions and light sabers been realized?
A long work with compositing techniques is needed to realize all the lightsabers with After Effects. The method used is a frame-by-frame positioning of the light beams because an efficient tracking is made impossible by the speed of the movements, by the image flickering and by other problems that limit its precision.
This kind of work is called Rotoscoping and consists in creating mobile masks that delimit the area of the blade’s core to which a glow of the desired color is applied.
It’s a work that requires much precision, but it is also very boring. Fabrizio Fenner has been entrusted with this tough job for many years.
The Explosions are realized almost completely with compositing techniques, but often it is possible to use video material specifically realized by shooting fire and explosions on a black or blue background. Some flying fragments and scraps, smoke and dust are a mix between 2d and 3d techniques.