Kinect guide: a preview and explanation of Microsoft's new full body motion sensor

By Paul Miller

posted June 17th 2010 2:02PM

Feature

We've become so familiar with the "Project Natal" codename over the years that our tongues are still having a little trouble wrapping around Microsoft's new Kinect moniker for it. Still, what's in a name? Microsoft has finally shown us what matters with real games, real gameplay, and real hardware, and after spending some time with it using our very own human flesh to control the on-screen action, we feel like we're starting to get a pretty good grip on the experience. Follow after the break as we break down the complicated workings and emergent gameplay of Kinect.

Hardware

Kinect combines a few detection mechanisms to build up a rather accurate and comprehensive amount of 3D data on what's going on inside a room. There's a color camera for taking pictures, recognizing faces, and so forth, but the real magic happens with the monochrome CMOS camera sensor that's paired up with an IR blaster. Microsoft calls this its "depth sensor," and the light and shadow of that image (lit by the human eye-invisible IR spectrum) is analyzed to build a 3D map of the objects within Kinect's field of view. Finally, there's a multi-array microphone setup to detect location of voices and to cancel out ambient noise, allowing for video chats without a headset.

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All of this sits atop a motorized tilting base of sorts. Microsoft hasn't gone into detail about the range of the motor, but when used in conjunction with skeletal and facial tracking, Kinect can pan and tilt to keep its sensors trained on you as you move around the room. One down side of the motorized base, however, along with the rest of the fairly complicated electronics, is that the Kinect hardware isn't tiny: it's about a hand's width tall, about as deep, and around a foot wide. When you think about it, the entire Wii occupies less cubic real estate. It shouldn't have much trouble squeezing in up in front of your LCD TV, but good luck trying to balance it on top, and we have no idea how folks who hang their TVs on the wall should approach this situation.

That motorized base also draws a good bit of power, so unless you have one of the brand new Xbox 360s, which include a special powered USB port, you'll have to plug Kinect into your wall as well as your 360.

One thing that Microsoft has actually left out of Kinect is a dedicated processor. The original plan was purportedly to have the Kinect pull its own load, allowing the Xbox 360's processors to run free in rendering games. In the interest of cost, however, the processor got cut and now the Xbox is taking a 10-15% processor hit. Reports are conflicting as to whether or not that's going to impact the sort of games that make it onto the system, but either way it pretty much rules out retrofitting older games for a new Kinect control scheme.

We've heard divergent reports on lag, but 100-150ms seems to be around where Kinect is playing (Sony claims a 22ms lag for PlayStation Move). During that time the system is tracking and processing 48 skeleton points in 3D space, watching up to two people, and repeating the process at around 30 fps.

Xbox Dashboard

While the main point of all this wild hardware and millions of dollars of Microsoft R&D is to play games, there's also a whole new Xbox UI that's enabled by Kinect. You wave your hand to dive into it from the regular Dashboard, and you're presented with a simple grid interface. There your hand is virtualized by a white dot floating around on the screen, which acts as a simple, accurate cursor. Hovering over icons pops out a bit of visual flare, and if you hover for a few seconds a timer fills up and that item is opened.