Enhancement request: 3D tracking capability

[AravindaDP]

@tysik,

While searching for ROS packages that could track noisy object detections I came across your package. I really like well organized modular architecture of this package where each node/nodelet fulfils a well defined task.

I have a suggestion to extend the obstacle_tracker node to track on full 3D space. While it is not required for this package I believe defined in/out topics makes a good case to use this particular node itself with other detection nodes (That operates on RADAR/Point Cloud). I think that enhancement would not effect the current intended functionality where we can think of 2D tracking as a special case of 3D tracking where z is always 0.

Please let me know your thoughts. If you think it's worthwhile but would welcome a PR rather than spending your valuable time let me know. I would be happy to chip in.

Looking forward to positive response.