Microsoft has allowed the public to get their hands on its new hands-free games controller for the first time.

微软发布新式游戏控制装置，可以使用户解放自己的双手。

The US firm showed off the "Natal¹" technology, designed for use with its Xbox 360 console（控制台，操控台）, at the European games convention gamescom in Germany.

The controller uses a microphone combined with visual and infrared² cameras（红外摄像机） to control the onscreen action.

It was first unveiled at the E3 Expo in Los Angeles in June this year, but had not been on public display until now.

Kudo Tsunoda, Xbox 360's general manager and creative director of Natal, said that as consoles evolved from being a dedicated³ games machine into "living room entertainment", it was important to develop a new control interface⁴.

"The current controller is a barrier to some people using our console," he said.

"To many users, the vast array of buttons and analogue⁵（类似物，模拟） sticks is plain confusing."

Mr Tsunoda said that Natal would allow casual users to use the console while at the same time delivering "extra fidelity⁶ to core users".

Two demos were on show at gamescom for people to try out, including a playable version of Burnout Paradise in which users control cars using an imaginary steering⁷ wheel, moving their feet forwards or backwards⁸ to control the speed.

Heat maps

At the heart of the Natal system is an infrared sensor⁹ that detects a person, their movements and their distance from the sensor.

The device calibrates¹⁰（测定，校正） itself to the room's temperature and then looks for warm bodies around the room.

Once detected, it scans the person's shape and tries to match it against profiles it stores in its memory. If the person is new, it asks them to create a new profile.

If it finds a match, it loads the person's profile and begins to work out their position. If a person moves towards the sensor they become "hotter"; as they step back they get "colder".

Natal plots 48 different points on a person's body, such as hands, feet and elbows, to create a wire-frame virtual manikin（侏儒，时装模特儿） that mimics¹¹（模仿） a person's movements.

Mr Tsunoda said that this means that even if someone - or something - were to move in front of a player, the sensor would not get confused, providing some of the player was still visible.

The system will allow players to automatically log on to the Xbox Live network, which allows players to compete with other gamers across the internet.

It would also monitor and adapt as people change shape, he added.

"If you take a young child, they grow at quite a fast rate," he said.

"However, these changes over days or weeks are slight. So if there are small day-to-day changes, Natal will recognise that and update your profile."

Mr Tsunoda said that because everything was done in infrared, it negated¹²（否定，否认） any problems they could have encountered with normal light.

"Clothes, people, size, lighting¹³ - we're making Natal so it will work in all conditions.

"And, yes, you can even log in and play Natal in the dark."