Try to lable my own point cloud

### Checklist

- [X] I have searched for [similar issues](https://github.com/isl-org/Open3D-ML/issues).
- [X] I have tested with the [latest development wheel](http://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [X] I have checked the [release documentation](http://www.open3d.org/docs/release/) and the [latest documentation](http://www.open3d.org/docs/latest/) (for `master` branch).

### My Question

Hi

I am new in this field
i still have a problem to predaict a correct lable to my own data by using opene3 ml toronto3d
i try to test by using one file from the data set (L001.ply) and convert it to my dataset (L001.xyz). after run the predict lable is not equal to the well known lable for the L001.ply

https://colab.research.google.com/drive/1IwGr8hR6pUcl7b91KSsF61gb4-0fuiK6#scrollTo=As7OdBvJEdYw