Justin Williams takes off a virtual-reality (VR) headset and wobbles away from a demo. The bottoms of his feet and calves are “on fire,” he says. Mr. Williams was playing “Sprint Vector”, a VR running game: players swing hand-held controllers to simulate motion. Though he has been standing in one place, his brain believes he has just run for several miles.

This sensation of complete immersion is called “presence”. Boosters of VR say it is what will drive the technology’s mass adoption, in time. When Facebook bought Oculus, a VR startup, for $2bn in 2014, and sent interest in the technology rocketing, it was this feeling of being present that Mark Zuckerberg, described as “incredible”.

Several obstacles still stand in the way of widespread use. The gear is expensive and clunky, and requires a powerful computer or gaming console to function. Consumers are hesitant to splash out on expensive kit when there isn’t a lot to do with it; developers are reluctant to spend resources making games for a tiny market. The way in which users must wave around hand-held controllers to input movements falls short of the promise of VR, which will eventually use sensors to convey bodily movement.

Some tech giants still see VR as integral to their future. Facebook is convinced that VR is “the next major computing platform”. It has a new offering, “Spaces”, which is a place to socialize with friends in VR that allows users to create avatars, to express some emotion through facial expressions, answer video calls, share photos and take selfies. As a first go, it is surprisingly compelling.

If VR is to take off at last, tech-industry executives agree that avid gamers will be crucial. Such people tend to be early adopters of expensive new equipment, so they subsidize innovation. Games developers know how to engage players and keep them interested, and how to tell stories in a non-linear fashion. And they have for years created content in three dimensions, a basic requirement for VR. Indeed, virtual reality is integrating games and the broader technology industry as never before. “It’s like two continents that were apart, and continental drift is bringing them together,” says Neil Trevett of the Khronos Group, a non-profit industry group.

Virtual reality also has new functions in business and beyond. VR producer says it receives many inquiries from carmakers, for example, which are using VR as a way quickly and cheaply to prototype and collaborate on new models of vehicles. Hospitals in America are experimenting with 3D models in VR as a way for doctors to get a closer look at tricky bits of bodies or to prep for surgery. The VR industry has not yet fulfilled the hype. But the believers have not lost their faith.

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