If you’re interested in virtual production or in-camera VFX, you know that accurate camera tracking is an essential element of both. Tracking in a static studio is fairly straightforward. But what happens when you need real-time camera tracking on location, where there are no walls or boundaries to observe? What if you’re filming a soccer pitch, a busy city street, or even a vast national park? Let’s break it down.
How does camera tracking work?
For any type of virtual production involving in-camera visualization or in-camera effects — whether on green/blue screen, using LED walls, indoors, or outdoors — the ability to accurately and robustly track the camera is a prerequisite. That means the ability to obtain the position and rotation of the camera in real time, known as 6DOF (degrees of freedom).
It is also important to understand the lens characteristics, meaning the optics and distortion parameters on any given frame, along with the focus, iris, and zoom (FIZ) readings. And this all needs to happen in real time, meaning at the same speed as the camera, whether 24fps or 60fps.
Most tracking systems rely on optical devices using markers, either inside-out (with the sensor mounted on the camera, viewing markers on the set) or outside-in (with sensors mounted on the set, viewing markers on the camera).
Using Ncam camera tracking outdoors
Many options on the market today use mechanical encoders to track pan and tilt only. But this type of tech cannot track a camera that is moving around; it only works for stationary cameras. By contrast, Ncam Reality lets users track any camera, lens, or rig, regardless of whether they are inside or outside.
The solution is made up of a small, lightweight sensor called the Camera Bar, a server device that runs the Ncam Reality software, and the software itself. The server device can be placed directly on the camera along with the sensor or, for a more lightweight setup, teams can use our Connection Box to connect to a generic server that is located elsewhere.
Using computer vision techniques to define a 3D point cloud representation of the surrounding environment, the software automatically determines the optimum tracking algorithm at any given point in time.
Ncam is the only system available that can track indoors and outdoors with 6DOF and, unlike other systems, it isn’t limited to a specific tracking method thanks to its ‘hybrid’ tracking capabilities; it can handle natural markers, fiducial markers, and reflective markers with high degrees of accuracy, giving users more flexibility. Since there is no need to prep your space, Ncam Reality works wherever you’re shooting, making it the go-to choice for live events, sports, and virtual production.
NetVenture: Outdoor camera tracking in difficult weather
Since 2017, NetVenture has been using Ncam on the ZDF Biathlon, a winter sports competition in Germany, enhancing their pre-and post- shows with augmented reality graphics.
“Since the majority of productions we support are outdoors, we need a camera tracking solution that works anywhere,” says Philip Wergin of NetVenture. “Working outdoors is especially challenging, because every set is totally different and, particularly in winter sports, weather and lighting can change at a moment’s notice.”
To keep the setup on the camera as sleek and simple as possible, the team uses the Ncam Mk2 Camera Bar and Connection Box, plus an additional box built to power the camera bar and convert the signal to fiber, to reduce the number of cables on the camera and ensure weather-proofing. All signals are transported to a remote workspace, while the Ncam server processes tracking and delivers it to the team’s rendering engine.
For the NetVenture team, the fact that the Ncam system can be used easily both in-studio and outside is a major plus. With the Ncam Mk2, the team can also track markers in addition to natural features, allowing for even more flexibility — for example, in studio situations with large LED walls or complex lighting situations that make tracking natural features challenging. And, thanks to Ncam’s small form factor, it is simple to mount it to cranes, Steadicam systems, or any other kind of camera rig.
“This kind of flexibility makes Ncam the system of choice for almost any kind of virtual production,” says Wergin. “Our customers need a system that is very fast to set up and has reliable tracking, without the use of any markers. Ncam delivers on both.”
To learn more about outdoor camera tracking and see a demo, get in touch.