According to this picture:
the iPhone X has an infrared camera. It is primarily used for face detection but there are other uses for infrared. Can it be accessed directly?
not via the approved iOS API library calls. But undocumented API should be possible if you guess how to do it.
Still not sure about infrared but to read the depth information from the iPhone X TrueDepth camera, we can use the AVDepthData class and related APIs. Here's a tutorial.
The company, reallusion.com makes a 3D animation product called 'iclone 7' which interfaces with the iPhone infrared camera. Try contacting them about how they do it. if not proprietary, they might at least give you a clue.
来源：https://stackoverflow.com/questions/47190065/is-it-possible-to-access-the-infrared-camera-on-iphone-x