After Paul Walker's tragic death in 2013 in a car accident during the production of Fast and Furious 7, Universal Pictures had to take a complicated decision: to leave the incomplete movie or to do everything for ending it by using the available technology.
To obtain the "resurrection" of Walker, the persons in charge of " Furious 7" they appealed the generation of images for computer, CGI (computer-generated imaginery).
To achieve it, they worked with the company:
Which devotes itself to the creation of visual digital effects, created in 1993 and co-founded by the director of cinema Peter Jacskon, person in charge of the trilogy of " The Lord of the Rings" and “The Hobbit “.
In addition, the producers of the movie used as doubles of body two brothers of the actor to realize the back planes in which one does not see Walker's face. Also there were in use scenes of the previous movies of the saga, in which Walker was appearing, but that were never used, for what the script of the movie was adapted in order that they were fitting.
The first thing that was done, was to use a double of body with a physical aspect similar to the actor, the majority of the scenes being filmed by this double. Then the face of the double was replaced with Paul Walker’s. Technologies of animation were in use for assuring him that the movements of this face should fit with those of the double in order that it had a natural aspect.
In case of Walker, it is very probable that a model was had in 3D of the face of the actor done with a scanner or a system of chambers before he died, since this is something habitual in the movies of action in which often the face of an actor is projected in of someone of his doubles for the dangerous scenes.
The delays in the filming caused by Walker's death, added to CGI's use, did that the budget of the movie was increasing 50 million dollars, up to finally reaching 250 million dollars.
Many of the spectators have tried to find the difference, but the certain thing is that the technology is so sophisticated, that is very difficult to distinguish between the real Paul Walker and the generated one in computer.