Some questions about KinectCalib

Hi, Robert.
I have some questions about KinectCalib.cpp

**Q1.** In function void reconstruct(...) {}. At line:256
https://github.com/robbeofficial/KinectCalib/blob/master/KinectCalib.cpp#L256

```
float Z = depth[i] / 1000.0f; // TODO pythagoras
```

Why here the _depth[i]_ divided by 1000.0f?

Is it means unit from millimeter to meter?

Dos it relative to chess board square size unit?
