Project Tango is one of those Google projects that's simultaneously futuristic and a bit clunky. It's "augmented reality" from before that term referred to head-mounted displays like HoloLens and Magic Leap: a series of sensors that let a smartphone or tablet map 3D space, then overlay it with virtual objects that appear on the screen. There are some eminently practical uses of this, like helping people navigate a building the way Google Maps lets them navigate a city, and we've heard reports that Tango might be expanding to pursue them. At Google I/O, we're still waiting on any news about that, but we've gotten a look at some of Google's more interesting experiments.

Lots of people probably remember smartphone augmented reality apps that slapped images on top of a camera feed. But Tango is more sophisticated than that. Using an infrared projector and a couple of extra cameras, it can detect things like walls and floors with reasonable accuracy, or capture a detailed 3D scan of a space. In the simplest cases, that just means that digital objects can look like they're sitting on the real floor. A partnership with the American Museum of Natural History, for example, lets users place a dinosaur in front of them, changing its size or taking a picture with it.

A more sophisticated version of this is a game called Woorld, co-created by Katamari Damacy designer Keita Takahashi. Woorld is a little sandbox overlaid on a real-world environment, where players can place cartoon houses, clouds, plants, spaceships, or other props and discover interactions between them. Creatures can move around real obstacles, and some effects can modify the environment, like a spigot that slowly fills the room with water. We didn't have time to do a lot with it in our demo, but it's built on the same pleasant whimsy that defines a lot of Takahashi's work.

The problem with using Tango for fun is that so far, it's just not quite smooth or accurate enough to let you get lost in the experience. But as a tool, it makes a lot of sense. One of the experiments calculates real space measurements using lines drawn on top of it — if you want to measure the square footage of your apartment, for example, you'd trace the edges and let the app do the rest. Building on this, home improvement chain Lowe's has created something similar to its augmented and virtual reality "Holorooms," where customers can virtually remodel a home. Here, the app lets you place stoves, refrigerators, or other appliances on any blank section of floor, rotating or moving them to see how they might look alongside the rest of the decor.

Even with this, Google hasn't proved that Project Tango is something people should want on their everyday smartphones, especially because it requires a bulked-up battery to handle the extra sensors. But the system will get a chance to prove itself this summer, when Lenovo releases the first phone with Tango built in. Beyond that, these sensors could end up being rolled into Google's growing virtual reality program. But as far as we know, Tango isn't playing a significant part in Google's newly announced Daydream platform. While VR is going somewhat mainstream, Tango is clearly in the "tech demo" stage — but considering how many augmented and virtual reality projects Google has on its plate, that may not be a bad thing.