Setup instructions:

Clone this repository from github to your local Linux machine (Tested with Ubuntu 20.02 and ROS Noetic)
Run catkin build (or your normal catkin build procedure). You can also run build_ros.sh
Source your catkin files with source devel/setup.bash
Everything should build correctly or it will post a message about a missing package.
If you are missing a package, please apt install as normal with sudo apt install ros-noetic-PAKCAGE-NAME-HERE

Run instructions:

To launch the simulation environment of Gazebo and the drone, please run: start_world.sh
Once the Gazebo simulation window opens up, launch ORB-SLAM2
Remember to source your catkin files again (source devel/setup.bash)
Run ORB-SLAM2 using launch_orbslam2.sh

The drone can be controlled using ROS messages to the topic of /firefly/command/pose
For example: rostopic pub /firefly/command/pose geometry_msgs/PoseStamped "header: ... your message here (you can tab to complete the message)"
The message format is a standard PoseStamped message with xyz position and quaternion xyzw orientation
Camera feed from the drone is accessible at the topic /firefly/vi_sensor/left/image_raw
The Pose output from ORB-SLAM2 is available at the topic of /orb_slam2_rgbd/pose

The simulation environment is independently available at: https://github.com/ethz-asl/rotors_simulator
ORB-SLAM2 ROS package is available at: https://github.com/appliedAI-Initiative/orb_slam_2_ros