You probably know most fantasy blockbusters are stuffed with computer-generated (CG) effects making spaceships fly and superheroes clash. But digital visual effects are everywhere in modern filmmaking. To find out how this cutting-edge movie magic is created, we visited the London studios of effects company MPC.
MPC's work on Disney's 2016 version of The Jungle Book earned an Oscar. The entire jungle and all the animals were created with CG -- the only "real" thing in the movie is the young actor playing Mowgli, which meant he had to be filmed in such a way as to be carefully matched with the animated elements added later. So this shot, for example, begins with Mowgli hugging a model of one of his animal chums, filmed in front of a blue screen. This unaltered shot is known as a "plate".
The CG animal and background are then added to the plate.
The finished shot.
After the film has been shot, 3D modellers, animators and other visual effects artists work on each shot using software such as Maya and Nuke.
The process of creating effects is as technical as it is creative, with software using complex algorithms and character creation requiring expertise in everything from anatomy to the physics of water. As a result, the office is piled high with as many textbooks as movie magazines.
Footage is continually presented to supervisors, heads of department, the movie's visual effects supervisor and the director in cosy screening rooms dotted around the office. Rough temporary versions of each shot are generally shown until everyone's happy, as rendering shots in full detail takes a huge amount of time and processing power.
The MPC office is covered in memorabilia of previous jobs and concept art for future projects.
One wall is dominated by concept art from Prometheus.
Signed posters celebrate past projects.
Also on the walls are custom-made crew T-shirts celebrating each film. This shirt commemorates the Oscar-winning Jungle Book.
Even when apparently on location, many modern films, like the Pirates of the Caribbean movies, are shot on soundstages in front of blue or green screens.
The live action elements from the plate are then composited together with the CG elements.
When combining live action and CG elements it's important to perfectly match the different elements.
Lighting, reflections, camera movement and even the distortions of a particular camera lens have to be matched by the digital artists when they're creating the CG backgrounds and characters.
Visual effects traditionally refers to the effects added after shooting, but with today's complex techniques visual effects supervisors have to be on the set for movies like Prometheus to ensure each shot will work with what comes later.
In order to match shots like this, the effects team must capture lots of reference information on set. They use techniques like photographing silver and chrome balls to record the lighting conditions and using Lidar 3D scanning to map the location.
Extensive reference photos were taken in India, but for the actual shooting none of the cast and crew of The Jungle Book went anywhere near a jungle.
The CG environment was built from 3D-modelled trees and fauna, united with simulated water.
Special software is used to create simulated natural effects like water, smoke, flames and large groups of people. For this crowd shot from World War Z, only the pilot in the foreground is real.
Crowd-simulating software is designed to replicate the movement of actual crowds, so the algorithms had to be adjusted for the creepily unnatural swarming of World War Z's zombie mob.
Visual effects also create virtual people in much more detail. CG is often used to create fantastic-looking creatures like the apes of the Planet of the Apes movies or Marvel characters like Rocket Raccoon and Groot, but in Terminator Genisys a "digital double" was created to take years off star Arnold Schwarzenegger.
Another digitally de-aged character appeared in Blade Runner 2049, when MPC spent a year making a CG model of the character Rachael looking exactly as she did in the original movie. This picture shows the incredibly lifelike CG model.
Rachael's scene in 2049 began with the actors playing alongside a stand-in. Dots on her face would be used to track her facial movements.
The stand-in's face was then overlaid with the digital model.
The final result made it appear as if Rachael hadn't aged a day.
Digital animals and humans are built from the inside out so they move realistically. Underneath it all the rigging team builds a 3D skeleton with joints and bones that move realistically. Another layer of musculature is then added on top.
The skin is then added over the top.
Finally, the lighting team matches the lighting conditions of the scene as it was shot on set, which is where all those scrupulously collected reference photos and information come in.