In-camera VFX for blockbuster action film, RRR
Filmmaking is challenging at the best of times, but add hundreds of extras, intricate sets, and iconic locations into the mix, and those challenges can become daunting. Which was precisely the case for Indian blockbuster, RRR, directed by S. S. Rajamouli.
Set in early 20th century India, RRR follows two legendary revolutionaries and their fight to free India from the British Raj. It’s the age old rebellion story we all know and love, based on historical happenings with some fictitious hyperbole thrown in for solid entertainment value. And it’s ambitious, featuring intricate, large-scale action sequences with a multitude of moving parts, including cars, horses, elaborate sets… and some pretty heavy visual effects that include a menagerie of CG creatures.
What’s more, RRR is the biggest budget Indian movie to date, clocking in at $69 million and going on to gross over $160million worldwide.
Animatrik was brought on to help with camera tracking for some of the film’s largest set pieces. “There was a need for camera operators and the director to be able to see any CG elements while they were filming,” explains Ben Murray, motion capture supervisor at Animatrik. “With sequences as large as the ones we were involved with, it really helps to understand where a computer generated element is in the scene. But at the time, that kind of expertise just didn't exist locally.”
“So they had to import it from somewhere else.”
Increasingly, game engine technology is being used in previsualisation pipelines. The ability to model a whole scene and play through an animation in real time is an incredibly valuable one, while there’s an added bonus of fast iteration.
The film’s climactic scenes involved burning buildings and a plethora of CG animals, and the primary VFX vendor, MPC, had been working on previz assets and animations to demonstrate movements in the final shots. “They were using Unity to render out animated preview sequences,” says Ben.
Animatrik has built a global reputation for our work in motion capture, performance capture, and, importantly, camera tracking. We’re also, conveniently, a stone’s throw away from Unity’s specialist virtual production team, which is based in Vancouver.
Blending CG and reality
“It always ends up looking better when you combine real action with CGI, rather than relying entirely on the computer generated side,” Ben elaborates.
The filmmakers knew that animals, in particular, in key scenes would need to be CGI. It’s just not safe to have your lead actor chased round a burning set by a real tiger. But filming without a reference can complicate matters in post production. “MPC had already built previz animations,” says Ben, “so we were brought on to track the cameras so that the team on site could amalgamate the shots.”
Real-time camera tracking
“The biggest challenge was the heat,” jokes Ben. “But really, technically speaking, the process was very familiar, just at scale. We knew that we would be tracking cameras with hundreds of extras on location along with sweeping crane moves.”
Something that makes that process much smoother for filmmakers is to be able to see CG elements with live action footage simultaneously — to have previz displayed on camera monitors for operators and directors to see.
Adding any kind of CG element to a live plate requires some technical artistry. Previz models are prepared and tracked into, in this case, a Unity scene which is then combined live with the camera feed. The resulting composite is only but only displayed on monitors, leaving clean plates for post production teams to work with.
“For RRR, we used NCAM to track cameras in real time,” Ben adds. “There are other solutions, of course, but at the time we chose to go with this one because we knew the system would work for what we needed. NCAM data couldn’t be imported directly into Unity, though, so we built custom plugins for that. Which is part of what we were working on with the Unity team here in Vancouver.”
All told, the Animatrik team was on location in Hyderabad for just over a week. With some careful planning and collaboration with both Unity and MPC we were able to provide accurate camera tracking data to composite previz elements onto camera feeds in real time. "It just goes to show what can be achieved when teams from different companies work together and support each other," concludes Ben. “Without each piece of the puzzle playing its part, films as ambitious as RRR wouldn’t be possible. It’s a real credit to everyone involved.”