A world away from holding your smartphone up to your face, Google's upcoming standalone VR headsets will go head-to-head with the Oculus Rift and HTC Vive.

Google Cardboard democratised virtual reality — putting it within reach of anyone who owns a cheap cardboard viewer for holding their smartphone up to their face — but it's far from a truly immersive experience.

Cardboard doesn't let you walk around or use your hands, unlike more expensive VR rivals like the HTC Vive, Oculus Rift and PlayStation VR. They all use external cameras to track your real-world movements, but the headsets are attached to a computer or games console, which limits how far you can roam.

Google started to close the gap with last year's Daydream View headset for Daydream-certified Android phones, with a headstrap that leaves your hands free to use the Daydream controller. The controller lets you grab and use objects, but you can't see your hands and manipulate objects with the same dexterity offered by the high-end VR headsets.

Daydream View took longer than Cardboard to find its feet, overshadowed by the similar Samsung Gear VR, and always felt like a stepping stone to greater things. Like the new standalone Daydream VR headsets announced at last week's Google I/O developer conference.

The headsets will have built-in screens and optimised mobile-style hardware, rather than relying on a smartphone or attached PC/console. They will also take advantage of WorldSense "inside out" tracking courtesy of Google's Tango augmented reality platform, letting the headset track your surroundings so you don't walk into walls.

Rather than building the headsets itself, Google is handing a Qualcomm-based reference design to hardware partners, with the first two headsets to come from VR veteran HTC and AR veteran Lenovo.

While Google's new free-roaming Daydream headset promises the best of both worlds, virtual reality is still in its infancy, says Clay Bavor, head of Google's VR division.

"We're a long way from reaching the 'iPhone' moment of VR," Bavor says.

"Meanwhile I'm not concerned about the rate at which people are adopting the technology because I still see us at the very beginning of VR. It's not a question of 'if' but 'when', so I'm comfortable with 'when' being a few years away."

The real game-changer with Google's latest VR announcements is the Seurat graphic overhaul, which lets VR content makers import high-end games and cinema-quality video from professional VR editing suites like Unity, Unreal and Maya. Rather than simply scaling down PC-based VR, Seurat scans original content and builds entirely new 3D models, reducing textures and polygon counts supposedly without a noticeable impact on image quality.

Designed to work on the new standalone Daydream VR headsets as well as Daydream-certified phones, Seurat will put them on par with high-end VR headsets reliant on a PC or games console. Put to the test on Rogue One: A Star Wars Story video clips from Industrial Light and Magic, the new platform renders 3D scenes in 13 milliseconds rather than the 1 hour required in an ILM server farm.

"In terms of the user experience I'd certainly compare these new standalone Daydream headsets more to PC-based headsets than to viewers which rely on a smartphone", Bavor says.

While combining WorldSense tracking with a completely wireless headset will offer a new level of free-roaming VR, efforts to import high-end VR experiences will still be hampered by the fact that users are reliant on the basic Daydream handheld controller rather than the more advanced handsets offered by rivals.

Google isn't planning to overhaul Daydream's WorldSense tracking and handheld controller for now, but Bavor acknowledges that Daydream and Tango always seemed destined to intertwine.

"We're starting to put the pieces together across both VR and AR and see them as not two separate concepts but rather two different flavours of what what we call immersive computing," he says.

"They're both tied into the idea of blending the physical and digital worlds into a new level of spatial computing, it's still early days but you can already see how it's going to open up a whole new world."

Adam Turner travelled to the Google I/O conference in California as a guest of Google.