James Martin/CNET

SAN BRUNO, California -- In a cable car high above Japan, the country's distinctive architecture unfurls beneath me. I see clay kawara tiles covering rooftops, shimmering as the cable car gently swings.

Suddenly everything stops, then goes dim.

YouTube is buffering.

The experience, which took place in YouTube's unassuming headquarters here, underscores the promise and challenge of the video-streaming service's efforts to develop virtual reality. Wearing VR goggles puts you in a digital world that feels real. I almost knocked my water bottle off a table as I whipped around to see more of the stunning vista.

YouTube's VR vehicle of choice is Google's no-frills Cardboard headset that turns your smartphone into a VR viewer when you pop it into the contraption. The VR videos are dubbed 360 because they let you step into a scene you're watching and look up, down, around and behind you.

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"YouTube is about democratizing," said Kurt Wilms, senior product manager for YouTube VR. "It's about bringing this kind of video to everyone."

"It's about bringing this kind of video to everyone." Kurt Wilms, senior product manager for YouTube VR

Few outfits could democratize VR as quickly and fully as YouTube, the planet's most popular video site. Every month, a billion people -- keep in mind that's one out of every seven on the planet -- visit YouTube. They watch hundreds of millions of hours of video.

On Thursday, YouTube, which is part of Alphabet-owned Google, revealed the next phase in its plan for VR. You can now view the 360 videos in 3D. The site is also making every single video in YouTube's massive library viewable on Cardboard. Just open up YouTube's Android smartphone app, play a video and tap the Cardboard icon. For videos that weren't originally meant to be viewed through VR goggles, it will reformat them to look like you're watching in an Imax theater. (The feature will come to the YouTube app for Apple's iPhones soon, but YouTube didn't say when.)

James Martin/CNET

The implications are real. By making its entire video library workable with Cardboard, YouTube is creating the biggest collection of VR-ready videos in the world. That might not mean much now, but it could get YouTube's massive audience familiar with the idea of VR. That's especially crucial as the biggest tech giants in the world, including Facebook and Samsung, try to bring VR into the mainstream.

VR was once mostly the dream of video game makers, but Silicon Valley has expanded its vision for the technology. One promise is that it can make the world's wonders more accessible to everyone. That's one of the reasons Facebook bought VR goggle maker Oculus for $2 billion last year. It's also why Oculus teamed up with Samsung to create the Gear VR, a $99 headset that uses Samsung phones as screens.

Google's Cardboard is far cheaper. The company doesn't sell the headset itself but provides plans to other manufacturers. You can get a unit for around $25, far cheaper than the competition.

Enlarge Image YouTube

Google has made efforts to get Cardboard, which is named after the corrugated paper product, into classrooms around the world. It's starting in the US, UK, Australia, New Zealand and Brazil.

Like Cardboard, YouTube's virtual reality lab is spartan -- at least on the day I visit. It's a small room, maybe 240 square feet. In it are a table and couch, padding on the wall to muffle sound and some neon green tape on the floor. YouTube staff had removed the fun stuff it wasn't ready to talk about.

"They totally scrubbed it," a YouTube public relations person warned me as we rode the elevator up.

Jumping In

By making 360 videos in 3D as well, the aim is an even more lifelike look. To create that 3D effect, YouTube shows you a different stream for each eye. It's the same picture, but from a slightly shifted angle. Viewed at the same time, it mimics depth. That helps create a sense of transportation.

"The real world is incredibly fascinating," said Husain Bengali, a product manager for Jump, Google's initiative to allow people to create virtual reality experiences. But when you can't visit places in person, VR is the next best thing, he said. "We want to do that for more places than you could experience in a human lifetime."

Enlarge Image YouTube

Of course, for VR to really take off, people will need videos to watch. That's where Jump comes in. It's a camera-and-software system that lets people capture VR footage. Google has partnered with the camera maker GoPro to develop its first specialized VR rig, a 16-camera device called the Odyssey that sells for $15,000. You must apply to be able to buy it.

YouTube will make the cameras available to some creators later this year at YouTube Spaces, studios in cities including Los Angeles, Paris and London that are owned by the video site. If you have a large enough YouTube channel, you can go there for free to make videos and use resources like editing equipment and green screens.

While the camera rig is complex, YouTube's approach is not. The idea for now is to just see what happens.

Wilms admits that people don't need to see PewDiePie, the UK-based Swedish gamer sensation, or get makeup tips, in an Imax-style setting on Cardboard. But if you push the boundary, creators will start making videos knowing that people will be watching them in different ways.

"We are thinking through how video is evolving," said Sanjeev Verma, another YouTube product manager. "VR is a new platform. We want to see what people start asking for, start experimenting with."

YouTube still has kinks to work out, but the effort is promising. Even when my virtual trip was interrupted by buffering, the experience didn't stop. The scene was frozen, but I could still crane my head and take in the amazing view.