问题
Is it possible to calculate small distances with CoreMotion?
For example a user moves his iOS device up or down, left and right and facing the device in front of him (landscape).
回答1:
EDIT
Link as promised...
https://www.youtube.com/watch?v=C7JQ7Rpwn2k position stuff starts at about 23 minutes in.
His summary...
The best thing to do is to try and not use position in your app.
There is a video that I will find to show you. But short answer... No. The margin for error is too great and the integration that you have to do (twice) just amplifies this error.
At best you will end up with the device telling you it is slowly moving in one direction all the time.
At worst it could think it's hurtling around the planet.
2020 Update
So, iOS has added the measure app that does what the OP wanted. And uses a combination of accelerometer and gyroscope and magnetometer in the phone along with ARKit to get the external reference that I was talking about in this answer.
I’m not 100% certain but if you wanted to do something like the OP was asking you should be able to dig into ARKit and find some apis in there that do what you want.
👍🏻
来源：https://stackoverflow.com/questions/23602014/is-there-a-way-to-calculate-small-distances-with-coremotion