Right now I'm exploring features of iOS Depth camera and now I want to obtain the distance in real-world metrics between two points (for example, between two eyes).
I have successfully connected iOS Depth camera functionality and I have AVDepthData in my hands but I'm not quite sure how I can get a real-world distance between two specific points.
I believe I could calculate it if I have depth and viewing angle, but I don't see that the latter is presented as parameter. Also I know that this task could be handled with ARKit, but I'm really curious how I can implement it myself. I mean ARKit uses Depth camera as well, so there must be an algorithm where Depth maps is all I need to calculate the real distance
Could you please give me an advice how to tackle this task? Thanks in advance!