Review of 3D Cameras for AR Glasses

Daqri smart glasses rely on an array of cameras, including 3D Intel RealSense:

The company's Chief Scientist Daniel Wagner publishes a nice overview of 3D camera technologies together with AR glasses requirements for a depth camera:

"First, sensors need to be very small in order to integrate into headsets of comparably restricted size. For AR headsets, small can be defined as “mobile phone class sensors” in size,e.g., a camera module no more than 5mm thick.

Second, the depth camera should use as little power as possible, ideally something noticeably lower than 500 mW, since the overall heat dissipation capability of the average headset is just a few watts.

Third, in order to further save power, the depth camera should not require intensive processing of the sensor output since that would result in further power consumption.

For environmental scanning, the depth camera needs to see as far as possible — in practice roughly a range of around 60 cm to 5 meters.

In contrast, user input needs to work at only arm’s length, hence a range of around 20 to 100 cm.

Lastly, there is the matter of calibration. As automatic built-in self-calibration is not yet available, they rely on the factory calibration to remain valid over their lifetime, which can be a problem."