Clip Point clouds in the Ouster-CLI

Clip Command

The clip command clips the lidar scan by the given range and streams down the modified lidar scan to the subsequent commands (like slam, viz, save, etc.). The position of the clip command in the ouster-cli command chain makes a difference as it only affects the commands that follow it.

To explore the parameters you can use with the clip command, you can use the –help flag:

ouster-cli source <SENSOR_HOSTNAME> / <FILENAME> clip --help

Example Usage

To keep the points within the 20 m to 50 m range and save the modified lidar scan into a PCAP file with the visualizer on, run the following command:

ouster-cli source <SENSOR_HOSTNAME> / <FILENAME> clip --min-range 20 --max-range 50 viz save clipped.pcap

Remember, the clip command only affects the commands after it. In the following example, the viz command runs before the clip command, which means the point cloud modification won’t be reflected in the visualizer but will affect the subsequent save command and the saved PCAP file:

ouster-cli source <SENSOR_HOSTNAME> / <FILENAME> viz clip --min-range 20 --max-range 50 save clipped_2.pcap

In addition to the min-range and max-range parameters, the clip command also includes the percent-range parameter. This parameter discards points with ranges greater than a specified percentile in each lidar scan, helping to filter out noise points.

ouster-cli source <SENSOR_HOSTNAME> / <FILENAME> clip --percent-range 99 viz

Combined with SLAM Command

The slam command also has min-range and max-range parameters. When the clip command is used after the slam command, the clip command will, by default, use the range settings specified in the slam command. However, you can explicitly pass in the range settings to the clip command to apply different ranges to the clip operation.

Note that the range settings in the slam command only affect the point cloud within the SLAM algorithm. The slam range settings will not modify the lidar scan and will not affect the other following commands.

Example Usage

Experiment with the following commands using a pre-recorded PCAP or OSF file:

ouster-cli source <FILENAME> slam clip --min-range 20 --max-range 50 viz save clipped_3.ply
ouster-cli source <FILENAME> slam --min-range 10 --max-range 100 clip --min-range 20 --max-range 50 viz save clipped_4.ply

You can view the output PLY files using the open source software CloudCompare For more details about the slam command, refer to the SLAM Command