VR gamers can experience ‘ludicrous speed’ without motion sickness

A team of human-computer interaction specialists from the UK and Canada are said to have developed the first system to manage motion sickness in VR which also allows users to feel like they’re moving much faster or much slower than the vehicle they are travelling in. 

Their results suggest that controlling travellers’ perceptions of speed in virtual reality can provide experiences that could make games more exciting, or make it easier to focus on tasks like reading or working, while mitigating the potential for motion sickness.

Motion sickness is caused by a mismatch between the physical motion sensed by a person’s vestibular system and what is in front of their eyes. If the feeling of movement doesn’t match up to the perception of movement, it can make some people feel unwell very quickly. 

Some VR systems promise to reduce or eliminate motion sickness during travel by matching the physical movements of the vehicle to the perceived movement inside the headset.

The team set out to establish whether further manipulating VR users’ impressions of movement could provide enjoyable virtual experiences without making them feel unwell.

The outcome of their research is claimed to be the first travel-focused system to be built on the VR principles of translational gain and attenuation, where real-world movements are turned into virtual perceptions in ways that don’t have a one-to-one equivalence. 

In translational gain, a half-metre step in a user’s living room can be translated into a five-metre movement in a virtual space, generally without causing motion sickness. In translational attenuation, the process shrinks large real-world movements into smaller virtual ones.

In a statement, Dr Graham Wilson, of Glasgow University’s School of Computing Science, said: “VR technology is becoming more widely accepted and adopted for use in entertainment and productivity applications, but it can still make some people feel unwell, particularly in vehicles. 

“Exactly mapping real-world movements to virtual ones does a good job of reducing that feeling of sickness, but it limits the available types of experiences users can have, and reduces the range of feelings those experiences can create. It’s more difficult to make a movement-based game seem exciting if it’s constantly stopping and starting at traffic lights. Similarly, it’s hard to focus on writing an email if you’re feeling distracted by moving at motorway speeds.

“Translational gain and attenuation hold a lot of potential for more expanding the scope of VR experiences during travel. In this study, we set out to explore how that potential might be realised in real-world situations.”

Phase one

In the study’s first phase, 17 study participants wearing VR headsets were driven on a 2km stretch of road at a speed of around 50km/h. Inside their headset, they were presented with a virtual city street overlaid with some text they were asked to read as they moved through real city streets, followed by multiple choice questions based on the content.

Their perceived speed was set to match the movement of their vehicle, and then to move faster and slower, over the course of three hour-long sessions. In the faster-than-real-life study, their virtual speed was accelerated over four sections from 72km/h to 338km/h. In the slower-than-real-life study, they moved through the virtual city at reduced velocities, from 32km/h to 7km/h, or 14 per cent of their actual speed.

Dr Katharina Pöhlmann, of Canada’s KITE Research Institute, said: “Our participants reported that the accelerated sections of the study didn’t make them feel any more discomfort than the speed-matched sections, and that they didn’t feel the task was more challenging when they perceived they were going faster. They did report feeling more aware of motion sickness during the slower-than-real-life sections, but that they felt safer, more relaxed and more able to focus than they did during either the matched or accelerated velocity experiments.”

Phase two

In the second phase, they were presented with a game in which they flew through a trench on a spacecraft shooting at enemy ships flying towards them. Their in-game velocity was set to match the real-world speed for a short while. It then shifted every 300m between a range of faster and slower perceived movements from 14 per cent of real-world velocity to 950 per cent, which the team dubbed ‘ludicrous speed’.

Dr Pöhlmann said: “Here, the participants told us that they most enjoyed the ‘ludicrous speed’ sections of the study, which they felt helped increase the excitement and intensity of the action without making them feel sick. Switching between perceived speeds, however, reduced their enjoyment of the game.

“In both sections of the study, the participants said that their perception of how far they’d travelled in real life was affected by how fast or slow they were moving in VR.”

The team’s paper, titled ‘From Slow-Mo to Ludicrous Speed: Comfortably Manipulating the Perception of Linear In-Car VR Motion Through Vehicular Translational Gain and Attenuation’, will be presented at the Association of Computing Machinery CHI conference on Human Factors in Computing Systems in May, 2024.