Weta created the Imperial City and populated it with digital citizens.
A key assignment for the visual effects team behind Niki Caro’s Mulan, which premiered last March just prior to the pandemic lockdown and was recently launched on Disney+, was creating its vast world and populating it with digital extras. As Hollywood restarts production, there’s increased interest in these techniques, as visual effects are recommended in order to limit the number of actors required on set.
The estimated 2,000 VFX shots in the production were shared by multiple VFX houses, including lead shop Weta Digital, whose work included the enormous Imperial City and its population that included real and digital inhabitants.
There are numerous techniques that could be used to create digital extras. In the case of Mulan, it started with scanning 70 extras in full costume. “We specifically built a new photogrammetry rig of like 124 cameras that was very flexible. That allowed us to capture actors and props and extras very quickly,” explained Weta VFX supervisor Anders Langsland. “We came up with a system whereby we could very quickly and inexpensively go straight from that 3D scan from the photogrammetry rig into a moving character in our crowd system.” This crowd system used to animate the “extras” was the Scientific and Technical Academy Award-winning Massive, which initially became known when an earlier iteration of the software was used to create the digital armies in Peter Jackson’s VFX-Oscar-winning The Lord of the Rings trilogy.