SAN FRANCISCO, CA—This year’s Game Developer’s Conference in San Francisco was full of buzz about head-mounted virtual reality displays. Valve unveiled the HTC Vive headset running Steam VR, Sony gave us a closer look at its Project Morpheus, and John Carmack confirmed that Samsung and Oculus will turn the "Innovator Edition" of its Samsung Gear VR unit into a full consumer-grade HMD later this year. Everywhere you turned, you saw attendees strapping on the future-goggles to check out VR game demos. (I was particularly taken with Minority Media’s Time Machine.) But in a fascinating panel presentation, Disney’s Bei Yang encouraged game developers to think outside of the headset.

"When people talk about virtual reality these days, they’re generally talking about head-mounted displays," Yang told me before his presentation. "But we need to think in a broader context. VR is really about the human body as an input/output mechanism. It’s about spoofing inputs into the human perceptual system to create desired effects."

Yang is a creative technology executive with Disney Imagineering, the team that designs immersive experiences for rides, hotels, and cruise lines. Imagineers have always been adept at spoofing human perceptual inputs—like the stretching room and the ghosts in the 1969 attraction Haunted Mansion–and they’ve been implementing VR into rides for over 15 years. There’s Disney World’s Toy Story Midway Mania, which lets riders fire virtual darts at Disney characters. There’s Disneyland’s flight simulator Soarin’ Over California, which dispenses blasts of wind as well as citrus and pine smells as riders zoom through orange fields and forests. And there’s Tokyo Disney’s Goofy’s Paint 'n Play House, which lets kids launch blobs of color onto the walls of a room, thanks to an elaborate projection system.

"Practical Virtual Reality in Disney Theme Parks," Yang's talk last week, broke down exactly how VR can spoof our perceptions, and pointed out some ways in which HMDs will never be able to match the immersiveness of a ride. Visual input is important for a VR experience, but so is proprioception, the sense of where our bodies are positioned in relation to other things. And three-dimensional audio that shifts around you as your head turns can create an enveloping experience, but Yang reminded attendees that the tiny hairs on the cochleas in your ears don’t just perceive sound—they are also internal accelerometers that let you know your pitch and yaw and the direction of your movement.

Some of Yang’s advice was counterintuitive. VR headset makers have been killing themselves trying to cut down on latency—the lag between when your head turns and when the display registers that your head is turning—but Yang insisted that amount of latency is less important that the consistency of the latency. "Your brain is really good at adapting things, and it can handle a fair amount of latency," he said. "It’s variability of latency that causes motion sickness. Motion sickness feels a lot like being drunk because it is like being drunk. In both cases, you’re experiencing an input mismatch, and we’ve evolved to think that this input mismatch means that we have been poisoned. The nausea is just your body saying, 'Oh no, I’ve been poisoned, please eject everything.'"

According to Yang, VR was as integral to the building of Disney attractions as it is in the attractions themselves. Imagineers use tools like Digital Immersive Showroom to wander around a prototype version of an attraction before they begin any actual construction. "Building a theme park attraction is really expensive," Yang told me me. "If you’re going to mess up, it’s better to do it with bits instead of concrete." He discussed a VR system Disney uses to build life-sized environments on the fly with a pair of Wiimote-like mobile devices in each hand, and showed video of Imagineers walking around and inspect their handiwork as they build. He also pointed out that Minority Report-style interfaces are not a good idea—it may look cool, but no one would actually want to go to work and wave their arms in the air for eight hours.

Yang did have some advice for game designers working with HMDs. He believes that they’ll be particularly good for horror experiences. "When you see a scary movie in the theater, your friends are sitting right there next to you," he said. "But that headset is so isolating that it really makes you feel cut off and alone." He’s also keen to see VR real-time strategy games, where players can survey a virtual battlefield like a god looking down from on high. He talks about the surprising immersiveness of the decidedly old-school Disneyland experience Storybook Land Canal, even though it's just a slow boat ride past miniature versions of classic Disney settings. "When you make something very small, it makes people feel powerful," he says. "You don’t have to use pixels to make immersive environments."