Visualize_PCL_CropBox_ROS_Rviz

Visualize_PCL_CropBox_ROS_Rviz presents an approach For Debugging Transformation (TF) issues when working with PCL CropBox in ROS.

PCL Cropbox only keeps the portion of the point cloud which lies inside its bounds. If the coordinates and transformation of the Cropbox are incorrect, it can be difficult to correct the issue, especially when working with initial drafts of URDF files from clients and third parties.

In these situations, we ideally want a way to visualize the cropbox itself and use this as the initial point for debugging. One Approach to solve this issue is presented below.

Approach

1. Create a Ros Node which publishes a Cubic Point cloud to fill a section of the 3D Space in Rviz. The script cubic_point_cloud_publisher.py.

2. Provide this point cloud message to your ROS node which is using PCL Cropbox.

3. If the section of Rviz contains your Cropbox it should become visible in Rviz. If not adjust the size, location and spacing of the Cube until the Cropbox becomes visible.

Cubic_point_cloud_publisher

The cubic_point_cloud_publisher.py. publishes Cubic point cloud on the topic /point_cloud, which covers a section of the 3D Space in Rviz. Please use the CUBE_SIZE and CUBE_SPACING variables to change the size and density of the point cloud, respectively. To change the coordinates of the cube please vary the upper and lower bound on np.arrage used for the calculation x,y and z coordinates, as required.

NOTE: Please be careful when changing CUBE_SIZE and CUBE_SPACING variables, as rendering a large point cloud requires alot of processing power.

Sample CropBox_Filter

The sample Cropbox Filter is just proivded here for testing purposes. To build the nodes please execute the following command in the base directory of this repo:

cd sample_cropbox_filter

catkin_make

NOTE: Please make sure to source your ROS distro before executing the above. For example,

source /opt/ros/noetic/setup.bash

To run the node execute the following commands:

source devel/setup.bash

rosrun sample_pcl_cropbox_filter_node cropbox_filter_node

Supported Platforms

    Linux

ROS Version

    ROS1

NOTE: These ROS nodes were tested on ROS NEOTIC but they should be valid for other version of ROS1 which support PointCloud2 msg.