Giving roller coasters a digital twist with virtual reality
For more than a century, roller coasters have been a popular attraction in theme and amusement parks around the world.
Whether at SeaWorld in Florida or Alton Towers in the UK, these behemoths always draw the crowds.
Recent research found steel roller coasters are still the favourite attraction at most entertainment and theme parks around the globe. However, the digital age has ushered in a fresh spin on the rides: integrating virtual reality (VR) into the experience. While guests are attached to their seats and riding the real roller coaster, they’re supplied with a VR headset that presents an alternative world, ranging from the Wild West to flying through a galaxy.
From arcades to roller coasters
The world's first VR-enhanced roller coaster was launched at Europa-Park in Germany back in 2015. Since then, more than 30% of European producers have added VR enhancements to one or more of their operational roller coasters. If this trend continues, enjoying VR on coasters could soon become the norm.
These new rides can be thought of as an evolution of the old-school simulators that were popular in the 80s, which were effectively small movie theatres attached to hydraulics. These rides would show film shots from a roller coaster car, while the machine mimicked the action seen on screen.
The market leading purveyor of today’s VR roller coasters is virtual reality experience company VR Coaster, who use a unique graphics system that combines 4K stereoscopic video at full 60 frames per second with interactive real-time components.
The very first iteration they tested involved attaching an Oculus Rift and a laptop onto the roller coaster with cables ties and duct tape.
This initial experimentation worked reasonably well, but at that point, nobody thought it would be feasible to deploy within a public operation where real people would be sitting in the cars.
VR roller coasters would be impossible if you had to have a laptop tethered to every seat, with the hardware breaking constantly and issues with energy supply.
What made the experience possible was mobile VR. The birth of mobile headsets allowed the VR Coaster team to attach compact, mobile hardware onto the heads of the people and remove the bulky computers from the rollercoaster.
Even with the breakthrough of mobile VR, there remained challenges to overcome before VR roller coasters could become commercially viable. It’s not easy to create media for a rollercoaster ride, because it’s a very different beast to a classic simulator.
Keep your eyes forward
On a classic simulator, you always know that the guest is sitting in a chair, and that they’re looking at the screen—they won’t look anywhere else. If you want to simulate a curve, you just rotate the curve of the animation.
But on VR roller coaster, you can't distinguish between the guest turning their heads to the right and the entire car turning to the right (and therefore everybody turning to the right), so absolute tracking must be used. You don't have this if you play an Oculus game on your couch at home—there you just have relative tracking.
On VR coaster, you always have to have a parallax: you need to be able to look anywhere at any time. The only way to do this is to keep the virtual vehicle, that you see in the virtual world in your virtual seat, exactly aligned with the rotation of the real view. The key is accurate synchronization, and that is solved with the ‘black box’—a small, very robust computer that gets attached to VR coaster trains, which transmits the location of the train, 30 times a second. All the headsets that receive that signal can decode it and provide accurate, synchronized visuals to the wearer.
Another challenge to overcome was put to the VR Coaster team by one of their first theme park clients, who wanted to move away from real-time graphic constraints and use fully pre-rendered footage. It was a conundrum, because the team didn’t want to end up with a 30 fps monoscopic video that ran at too low a frame rate and was too blurry.
The answer was hardware coding, using files that can be decoded very quickly by the GPU of the mobile hardware devices.
With this in place, the team could stream a huge amount of image data—namely stereoscopic panorama in 4Kx4K—and have 30GB of data for two minutes of ride animation. The end result is the feeling of being in a large IMAX theatre but on a moving ride.
The team even went a step further, realising they could actually have real-time graphics in the foreground. They created a sphere with a pre-rendered stereoscopic panorama, and inside of that sphere, everything close to the guest is rendered in real-time 3D. Because only very few objects need to be real-time 3D, they can be highly detailed—something like Superman would have over 80,000 polygons, which is enough to make it look good even on a mobile device. The team even coined a name for this mix of pre-rendered and real time visualization: Hybrid VR.
Another innovative development the team worked on was adding a free-roaming aspect to some of their rides.
On these, guests put on their headsets long before they actually sit in the coaster. They can explore a virtual environment, take a look around, and then eventually be directed by visual cues to sit down. However, the seat is not just any seat. It’s the seat of a roller coaster or drop tower, and seamlessly, without taking off the headset, they experience the ride.
The future is VR
VR Coaster has evolved a long way from the humble beginnings of laptops duct-taped to roller coaster carriages, bringing their VR roller coasters to 60 theme parks worldwide.
They’ve even started looking beyond traditional coasters, recently launching their first VR bumper cars attraction and the very first underwater VR experience. Make sure you keep an eye out—there could soon be one coming to a theme park near you.
