3D on phone

Nokia had allegedly been working on gestural navigation before Microsoft bought it up. Via WP Central

The 3D Touch program could certainly simplify some interactions with your phone, or streamline it by stripping off buttons, like the volume rocker. Likewise, gestures can be tricky if they require users to learn a new navigational system without any button backups, two lessons from the and even lesser-known .

Since a gesture-navigated device has to make sure you're really intending to complete a task and not just randomly moving around, some motions could also wind up taking longer to complete than if you just mashed your fingers on the screen. To really give Windows Phone an edge over Android and iOS, Microsoft would have to get 3D Touch just right.

3D interface moves with you

Off-screen navigation may be one direction that 3D smartphones are headed in, but as Amazon demonstrated with its Fire Phone, 3D can also refer to the way that an interface looks and responds to you.

3D wallpapers, mapping, gaming, and shopping through Amazon's gargantuan shopping portal are the major ways Amazon is integrating a more immersive look and feel on its phone, thanks to the four tracking cameras on the phone's front.

A number of home-screen replacement apps on Android impart a 3D look and feel to a phone's interface, and some of you may even remember Hitachi's Wooo H001 from 2009, with it's world's-first 3D interface (video). Amazon's skin, however, is much richer and more advanced than the efforts of five years ago, and several added motion controls go beyond passive viewing.

Real-time 3D modeling

The reference tablet that includes a 120-degree wide-angle camera, a motion tracking camera, and a depth sensor, which together will lead to all sorts of applications for 3D mapping, indoor modeling, and augmented reality. The sensors make a quarter million 3D measurements every second, Google says.

"Our goal is to give mobile devices a human scale understanding of space and motion, " Tango's project lead Johnny Lee said in Tango's introductory video (below).

Google has made some prototypes to illustrate what developers can do with Tango, like create a gaming environment mapped to a user's living room, so that the game character walks when you do. Likewise, visually impaired people could benefit from auditory cues as a device running Project Tango could help circumvent obstacles in real time.

Preparing for a 3D world

It's clear with these strong rumors and big initiatives that "3D" phones are making a comeback, this time with far greater sensors, much more sophisticated software tools, and processors powerful enough to resolve graphics on the fly.

At this point, all three avenues have their promise and potential, but, like Samsung's ballyhooed eyeball tracking feature in the and wireless charging in any device, all that potential could still fall short of truly useful things we use every day.

For Amazon, Microsoft, and Google, translating their "3D" work into the most import space there is - the 3D phone or tablet in your hands - is a step toward turning mobile devices into even more potent and indispensable tools.