How to make a blazingly fast VR racing game (that won't make you sick)
It can be done
Since we started demoing our first virtual reality sci-fi arcade racing game, Radial-G : Racing Revolved, at events in early 2014, we have seen nothing but genuine surprise at how comfortable 99 percent of players find the game experience.
We are now fully launched on the Oculus and Steam stores, and the former has a "comfort rating" applied to titles determined by the Oculus Store team. We are rated "Intense," and frankly, if we weren’t, we’d have failed in our goal of making the fastest yet most comfortable arcade racing game for VR. Now we're busy preparing to launch on the Sony PlayStation VR system this month.
Places where we’ve shown the game have included both small-scale efforts like VR meetups with 100 attendees and large-scale efforts like EGX Rezzed with hundreds of thousnads of attendees. We reckon over the years we’ve demoed the game to over 6,000 people and, keeping a check of our log book, under one percent of players have had to stop and remove the VR HMD before 20 seconds of gameplay is up.
How have we achieved this?
I have highlighted some key areas of VR design in the screenshot below. These were prototyped and tested extensively by the team to determine what did and didn’t work well in VR and what was comfortable for us and, when ready, for test users.
Note that, back then, we were early adopter developers working with the first Oculus development kit that had no positional tracking. There weren’t many experiences available to compare against. We had no "VR legs" and felt ill regularly throughout development and testing.
These days, with the improvements in the technology like higher screen resolutions, lower latencies, higher refresh rates and 1:1 tracking, it’s hard to make us sick through the technology; we only fall ill due to badly designed and developed VR experiences.
Screenshot showing cockpit from Radial-G : Racing Evolved with The Hound ship
- Lack of horizon : Without knowing what is up from what is down, it’s harder to get disorientated. No horizon means no sensation of looking out of a ship window on a rough sea. Furthermore, the sci-fi space setting lets the user’s brain know it’s not real and just a bit of fun, so they can relax more.
- Put the player in a cockpit : Placing the user in a cockpit puts them in a safe space that is logical, expected and helps ground them to the experience. It also matches where they are in the real world, i.e. sitting down, with where we have placed them in the virtual world. There is a natural connection between the two realms that further grounds the user.
- Magic side bars of awesome : As soon as we added these, we realized that these greatly but subconsciously distracted a user’s brain, keeping focus in the foreground rather than on what we were, or they were when steering, doing around them with the environment.
- Magic central bar of awesome : See above. It’s a bit hard to see in a still image, but these are aspects built into the cockpits of these ships. It’s just a matter of making visual elements wrap around the cockpit to be seen above and around the player. And please don’t steal our very technical terms for these graphical elements.
- Central track : While fairly critical to the game, it also provides a central unchanging element that the user can focus on. As the track twists and turns, the better a user gets at the game and understands how a true sci-fi race master drives, the more comfortable it is for them. Most first-time users or those who have only played traditional flat-track racers think that straight line speed matters most, so they don’t steer very often. This often lets the inertia carry them to the outside, the slow side, of the track. A master understands that when the track is rising up in front of them it means that they are on the inside of the tube, therefore on the shortest and fastest section. A novice races constantly on the outside of the tube, as if they are cresting over the brow of a hill, which also makes it uncomfortable since they cannot see what is coming up. They don’t have the track in front to ground them and typically get frustrated. It only takes a couple of races for them to realize their mistake, however, and soon their comfort level and enjoyment increases.
- Cockpit visor effects : Every time the user comes into contact with something, or something happens to the ship, we apply a red or green effect to the cockpit visor to mask changes to the environment around them. This can mean acceleration or deceleration when they hit a speed boost or slowdown gate or flip upside down in the tunnels. Since a change in velocity is one of the primary causes of nausea within VR, but hard for us to avoid being a racing game, this allows us to again distract the user from such visual side-effects of their behavior.
You can watch this trailer for our latest update to see all these tricks in action.
Other nausea factors
Nausea can be caused by a variety of uncontrollable factors, however, such as age and health of a user, the ambient temperature of the real world environment they are playing in or surrounding noise levels.
Nausea can also be reduced by a variety of factors that aren’t our doing, such as the stability of the commercial hardware from Oculus and HTC compared to earlier hardware and the power available from the latest ranges of GFX cards from AMD and Nvidia, ensuring that the game is rock solid at 90Hz always every time.
The first Oculus Development Kit, or DK1 Sebastian Stabinger
We know some of our peers were unable to play Radial-G : Racing Revolved without feeling nauseous all the way through development on the first two development kits, and it wasn’t until the commercial launch of the Oculus Rift that they were able to play comfortably. With our early demo on Oculus DK1 though, some others of our VR peers often asked if we’d hacked the HMD because they couldn’t believe the performance and visuals we had achieved.
Ahh, sweet memories.
A/B Testing and the "nocebo" effect
After a couple of events of finding ourselves explaining VR and how Radial-G could be extreme as a first-time virtual reality experience for would-be players in the queue, patiently awaiting their turn, we noticed that we were subconsciously planting a negative seed in the minds of players about how they were going to feel playing the game.
Therefore we started doing some A/B tests on the queueing event attendees, purposefully not mentioning or warning about potential side-effects of VR, and specifically something as hardcore and high-speed as our game, as a first-time experience.
What we saw was a reduced number of people who went into the demo expecting to feel nauseous and having that sensation as a result.
While not 100 percent scientific, and it’s arguable whether you should warn people about the (potential) side-effects of VR, we felt it best not to mention nausea unless specifically asked. In that case, we would inquire as to whether they generally get motion sick in moving vehicles and can correlate those who do to those who are more likely to feel "funny" in VR.
Our biggest challenge of late was with a pregnant woman who was one day away from her due date. After much warning and agreement that we wouldn’t be held accountable for any mishaps, she happily played the game without any ill effects.
If the game does make you feel nauseous, make sure your PC is fully VR-ready. Make sure you are playing properly; race on the inside with the track coming up in front of you rather than cresting the brow of the hill. If that doesn’t help, then at least you can call yourself the one percent of something.
Our award-winning high-speed, arcade sci-fi racer "Radial-G : Racing Revolved" is available now on the Oculus Store for Oculus Rift and also on the Steam which supports Oculus Rift, HTC Vive and OSVR. The Sony PlayStation VR version launches in October.