described the system as a "form of pure creation where if you want to move a tree or a mountain or the sky or change the time of day, you have complete control over the elements". Cameron gave fellow directors Steven Spielberg and Peter Jackson a chance to test the new technology. Spielberg said, "I like to think of it as digital makeup, not augmented animation ... Motion capture brings the director back to a kind of intimacy that actors and directors only know when they're working in live theater." Spielberg and George Lucas were also able to visit the set to watch Cameron direct with the equipment. To film the shots where CGI interacts with live action, a unique camera referred to as a "simulcam" was used, a merger of the 3-D fusion camera and the virtual camera systems. While filming live action in real time with the simulcam, the CGI images captured with the virtual camera or designed from scratch, are superimposed over the live action images as in augmented reality and shown on a small monitor, making it possible for the director to instruct the actors how to relate to the virtual material in the scene. Due to Cameron's personal convictions about climate change, he allowed only plant-based (vegan) food to be served on set. Visual effects A number of innovative visual effects techniques were used during production. According to Cameron, work on the film had been delayed since the 1990s to allow the techniques to reach the necessary degree of advancement to adequately portray his vision of the film. The director planned to make use of photorealistic computer-generated characters, created using new motion capture animation technologies he had been developing in the 14 months leading up to . Innovations include a new system for lighting massive areas like Pandora's jungle, a motion-capture stage or "volume" six times larger than any previously used, and an improved method of capturing facial expressions, enabling full performance capture. To achieve the face capturing, actors wore individually made skull caps fitted with a tiny camera positioned in front of the actors' faces; the information collected about their facial expressions and eyes is then transmitted to computers. According to Cameron, the method allows the filmmakers to transfer 100% of the actors' physical performances to their digital counterparts. Besides the performance capture data which were transferred directly to the computers, numerous reference cameras