During a high speed run on a rooftop, all background cityscapes, buildings, helicopters, bullet impacts on walls, broken and flying glass, debris and destruction of the glass pyramids were created in CG.

During a high speed run on a rooftop, as Violet is targeted by helicopters, all background cityscapes, buildings, helicopters, bullet impacts on walls, broken and flying glass, debris and destruction of the glass pyramids were created in CG. Only Violet, the bike and a few non-destroyed pyramids were shot practically. The helicopter destruction was created by combining the practical explosion of a 1/2-scale model hung from a 30-foot crane, with CG animation of the digital chopper.

CG Showdown
After surviving her high-speed confrontation with Daxus’ armed forces, Violet decides to meet her archenemy for a last showdown… only to bump into Daxus awaiting her with an army of hundreds! The plates were shot with a base of 100 extras only and without the benefit of motion control. “Given the extremely complex camera movement along all three axes while zooming out, the duplication of the soldiers turned out to be quite tricky,” Wong recalls. “We recorded all the location information and camera data for post camera 3D tracking using Maya Life. Then, we built digital stunt versions of the real soldiers, and mimicked their lighting and color-temperature using Maya. Finally, we used the 3D camera tracking data to render the digital stuntmen and composited the rendered images to the live action plates. One of the key aspects of the sequence was Violet’s sleek futuristic car. Kurt wanted a non-existing vehicle for this particular scene — something special since it would be a character. We realized it would be more cost-effective to realize it entirely in CG, and also to destroy it in the digital realm. By creating in CG the thousands of bullet hits and multiple debris, we could precisely control the timing of the destruction. We were also able to lay in quite a number of practical spark hits and metal destruction arranged for us by Darrell Pritchett.”

This CGI cityscape features the “Needle,” headquarters of Nerva. Note the aftermath of a major fight sequence in the orange circle/landing pad.

Although action sequences and environments represented the majority of the visual effects shots, they were not the most complex assignments of the movie. The most demanding shots actually involved a fictitious technology called “flatspace” that allows objects to be assembled and disassembled on the fly through flatspace receptors. “Those shots required a high number of iterations because the artists were building a new physics from the ground up,” Wong comments. “At one point, Violet discovers that she’s unwittingly ‘kidnapped’ a key character with this technology. In order to design the flatspace around that character, we had to determine its texture, viscosity, lighting source, turbulence, etc. The substance inside flat space was defined as a new kind of liquid with non-standard physical properties. Since the character was stored inside the flat space, we would see him immersed inside this fast flowing and high viscosity fluid. We used Maya’s particle effects to create the new substance and then rotoscoped a 3D model of the character onto the real footage to get the profile/landscape for the liquid to flow onto and around. Visualizing a brand new technology and developing the language to discuss it with Kurt turned out to be quite an exhilarating challenge. We felt extremely fortunate at the opportunity to not only build basic visual effects for Ultraviolet, but to help create a whole new world as well.”

Alain Bielik is the founder and editor of renowned effects magazine S.F.X, published in France since 1991. He also contributes to various French publications and occasionally to Cinéfex. Last year, he organized a major special effects exhibition at the Musée International de la Miniature in Lyon, France.