Added package dependencies for rosdep (#36)

* added package depend

* added gz_sim depend

* updated readme(rosdep)

* added bash commands for percep_ws

* added python path note

README.md

@@ -126,19 +126,31 @@ Refer to the official [ROS 2 installation guide](https://docs.ros.org/en/humble/
     Now go ahead and clone this repository inside the "src" folder of the workspace you just created.
 
       ```bash
-      cd percep_ws/src    
-      git clone [email protected]:atom-robotics-lab/ros-perception-pipeline.git
+      cd percep_ws && git clone [email protected]:atom-robotics-lab/ros-perception-pipeline.git src/
       ```
+3. Install dependencies using rosdep
 
-3. Compile the package
+    Update Your rosdep before installation.
+
+    ```bash
+    rosdep update
+    ```
+
+    This command installs all the packages that the packages in your catkin workspace depend upon but are missing on your computer.
+    ```bash
+    rosdep install --from-paths src --ignore-src -r -y
+    ```
+
+4. Compile the package
 
     Follow this execution to compile your ROS 2 package
 
       ```bash
       colcon build --symlink-install
       ```
 
-4. Source your workspace
+5. Source your workspace
+
       ```bash
       source install/local_setup.bash
       ```
@@ -181,8 +193,25 @@ file according to your present working directory
 ros2 run object_detection ObjectDetection --ros-args --params-file src/ros-perception-pipeline/object_detection/config/object_detection.yaml
 ```
 
+**Note :** If your imports are not working while using a virtual environment, you'll need to manually set your `PYTHONPATH` environment variable.
+Follow these steps to do this :
+
+1. Activate your virtual environment
+
+2. Find out the path of your virtual environment's Python installation
+    ```bash
+    which Python
+    ```
+
+3. Set your `PYTHONPATH`
+    ```bash
+    export PYTHONPATH = {insert_your_python_path_here}
+    ```
+
+
 ### 3. Changing the Detector
 
+
 To change the object detector being used, you can change the parameters inside the object_detection.yaml file location inside 
 the **config** folder. 
 

object_detection/package.xml

@@ -11,7 +11,9 @@
   <test_depend>ament_flake8</test_depend>
   <test_depend>ament_pep257</test_depend>
   <test_depend>python3-pytest</test_depend>
-
+  <exec_depend>vision_msgs</exec_depend>
+  <exec_depend>cv_bridge</exec_depend>
+
   <export>
     <build_type>ament_python</build_type>
   </export>

perception_bringup/package.xml

@@ -11,7 +11,8 @@
 
   <test_depend>ament_lint_auto</test_depend>
   <test_depend>ament_lint_common</test_depend>
-
+  <exec_depend>ros_gz</exec_depend>
+  <exec_depend>ros_gz_bridge</exec_depend>
   <export>
     <build_type>ament_cmake</build_type>
   </export>