dynamic_mesh

A ROS package that creates a filtered moving mesh from an incoming pointcloud topic.

• Quickstart
• Build
• Run
• Node

Author, Maintainer: Nikhil Sethi

Quickstart

To run with docker compose:

cd $DEV_WORKSPACE/src/dynamic_mesh
docker compose up -d

This will launch a container, in which it will automatically perform the build and launch options described below.

Build

# clone repo
mkdir -p ros2_ws/src
cd ros2_ws/src
git clone https://github.com/sam-xl/dynamic_mesh.git

# install dependencies
rosdep update
rosdep install --from-paths src --ignore-src -r -y

# build
colcon build --symlink-install --merge-install

Run

source install/setup.bash
ros2 run dynamic_mesh pcl_buffer_node --ros-args -r input_cloud:=/scancontrol_pointcloud -r output_mesh:=/cloud_mesh -p decay_time:=1 -p do_transform:=true -p frame_id:=base_link

Node

Subscribed topics:

• input_cloud (sensor_msgs/PointCloud2): The pointcloud from which the mesh will be made

Published topics:

• output_mesh (sensor_msgs/PointCloud2): The output mesh constructed from the pointcloud

Parameters:

• pcl_frequency (int, 400): The expected frequency in Hz at which the input_cloud topic is coming
• decay_time (int, 1): The number of seconds to keep buffering the pointcloud
• frame_id (string, "world"): The frame in which the mesh topic will be published and transformed if do_transform is true
• do_transform (bool, false): Transform the pointcloud into frame_id before creating the mesh. This is often needed because pointclouds need to be in a fixed frame to create a mesh

Details: The node works by accepting pointclouds on a topic, filtering them using voxel grids, and buffering them up into a FIFO buffer. The buffer length is determined by incoming frequncy and the decay time.

The process is memory efficient because, each pointcloud is filtered before being pushed into the buffer, so the overall global buffer size remains small.