Added time offset to the sensor_msgs/Pointcloud2 message.

[samkys]

Now it can be directly used and converted to PCL type, manipulated etc. We needed the timeoffset readily exposed to ROS and also be able to use PCL and ROS conversion tools for compatibility purposes.

Timeoffset is the same as the custom point message type, nanoseconds past the timestamp of the message.

[YangSiri]

Hi, @samkys

Could you please explain more about the timestamp? The stamp in /livox/lidar msg is relative time from the start of the lidar. Now i need the ros timestamp, how to calculate it?

Looking forward to your help :)