Getting Started

Pre-requisites

• ROS 2 (tested using ubuntu 20.04 and ROS2 Foxy or Galactic).

• Slicer built from source is required to build an extension, see Slicer build instructions. Remember the build directory for Slicer, it will be needed to compile the Slicer ROS 2 module.

Warning

Make sure we use the system/native OpenSSL libraries otherwise you’ll get some errors when compiling the Slicer ROS 2 module. After you ran CMake, in the Slicer build directory, set Slicer_USE_SYSTEM_OpenSLL ON using cmake . -DSlicer_USE_SYSTEM_OpenSSL=ON or ccmake.

Note

Older Slicer Make sure CMAKE_CXX_STANDARD is set to 14 (required to compile Slicer code along ROS 2).

Compilation

This code should be built with colcon as a ROS2 package. For now, we will assume the ROS workspace directory is ~/ros2_ws and the source code for this module has been cloned under ~/ros2_ws/src/slicer_ros2_module.

You will first need to source the ROS setup script for ROS 2 (foxy or galactic):

Then build the module using colcon while providing the path to your Slicer build directory:

Note

The -DSlicer_DIR... option is only needed for the first colcon build.

If you prefer to use CMake (ccmake) instead of passing the Slicer_DIR on the colcon command line, you can run colcon build once and then run ccmake on the slicer_ros2_module build directory.

Warning

You should see the following error messages if the Slicer_DIR is not set properly (or if Slicer has not been built from scratch):

Could not find a package configuration file provided by "Slicer" with any
of the following names:

SlicerConfig.cmake
slicer-config.cmake

If you see this message, run CMake on the build directory for slicer_ros2_module using ccmake ~/ros2_ws/build/slicer_ros2_module. In CMake, set Slicer_DIR to point to your Slicer build directory then hit c to configure until you can hit g to generate the makefiles. Then try to colcon build again (after cd ~/ros2_ws).