GitLab

Summary:
The following snippet should work in more cases.
     point_cloud = Pointclouds(
         [pcl.points_packed() for pcl in point_clouds],
         features=[pcl.features_packed() for pcl in point_clouds],
     )

We therefore allow features and normals inputs to be lists which contain some (but not all) Nones.

The initialization of a Pointclouds from empty data is also made a bit better now at working out how many feature channels there are.

Reviewed By: davnov134

Differential Revision: D31795089

fbshipit-source-id: 54bf941ba80672d699ffd5ac28927740e830f8ab