NodeletMUX represent a mux nodelet for PointCloud topics: it takes N (up to 8) input topics, and publishes all of them on one output topic. NodeletDEMUX represent a demux nodelet for PointCloud topics: it publishes 1 input topic to N output topics. PCDReader reads in a PCD (Point Cloud Data) v.5 file from disk and converts it to a PointCloud message. BAGReader reads in sensor_msgs/PointCloud2 messages from BAG files. PCDWriter writes a PointCloud message to disk in a PCD (Point Cloud Data) v.5 file format. PointCloudConcatenateFieldsSynchronizer is a special form of data synchronizer: it listens for a set of input PointCloud messages on the same topic, checks their timestamps, and concatenates their fields together into a single PointCloud output message. PointCloudConcatenateDataSynchronizer is a special form of data synchronizer: it listens for a set of input PointCloud messages on different topics, and concatenates them together into a single PointCloud output message.