Merge pull request #37 from SPARK/feature/improve_readme

Improve Readme

Author: ToniRV

README.md

@@ -60,15 +60,29 @@ source ~/.bashrc
 Download a [Euroc](https://projects.asl.ethz.ch/datasets/doku.php?id=kmavvisualinertialdatasets) rosbag: for example [V1_01_easy](http://robotics.ethz.ch/~asl-datasets/ijrr_euroc_mav_dataset/vicon_room1/V1_01_easy/V1_01_easy.bag).
 
 ## Online
-  - In one terminal, launch the SparkVIO ROS wrapper:
+  1. As a general good practice, open a new terminal and run: `roscore`
+
+  2. In another terminal, launch SparkVIO ROS wrapper:
   ```bash
   roslaunch spark_vio_ros spark_vio_ros_euroc.launch
   ```
-  - In another terminal, launch the downloaded Euroc rosbag:
+
+  3. In another terminal, launch rviz for visualization:
+  ```bash
+  rviz -d $(rospack find spark_vio_ros)/rviz/spark_vio_euroc.rviz
+  ```
+
+  4. Finally, in another terminal, launch the downloaded Euroc rosbag:
   ```bash
   rosbag play --clock /PATH/TO/EUROC_ROSBAG 
   ```
 
+  > Note that you will need to both source ROS and your `catkin_ws` for each new terminal unless you added the following lines to your `~/.bashrc` file:
+  > ```bash
+  > source /opt/ros/melodic/setup.bash  # Change `melodic` for your ROS distribution.
+  > source ~/catkin_ws/devel/setup.bash # Change `bash` to the shell you use.
+  > ```
+
 ## Offline
   In this mode, the provided rosbag will be first parsed and then sent to the VIO for processing.
   This is particularly useful when debugging to avoid potential ROS networking issues.
@@ -87,6 +101,9 @@ roslaunch spark_vio_ros spark_vio_ros_kitti.launch
 rosbag play --clock /PATH/TO/KITTI_ROSBAG 
 ```
   - In rviz, you can use the provided config file provided at spark_vio_ros/rviz/sparkvio_kitti.rviz
+  ```bash
+  rviz -d $(rospack find spark_vio_ros)/rviz/spark_vio_kitti.rviz
+  ```
 
 # Hardware use
 ## RealSense D435i (Infrared)