To enable this, Valve brought along some prototype headsets with positional tracking using desktop IR cameras.

为了能实现大赛宗旨，Valve带来了可在桌面红外摄像机上使用的有定位跟踪功能的原型耳机。

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"IR cameras cannot 'see' objects or humans behind flames because of the need for a zoom lens that concentrates the rays on the sensor to form the image, " he said.

BBC: fire fighting

"IR cameras cannot 'see' objects or humans behind flames because of the need for a zoom lens that concentrates the rays on the sensor to form the image, " says Pietro Ferraro of the Consiglio Nazionale delle Ricerche (CNR) Istituto Nazionale di Ottica in Italy.

ENGADGET: Infrared holography lets rescuers see people through walls, fire, walls of fire (video)