Using Gazebo

1. Inserting a new model into Gazebo
    
  a) Making CAD in stl file 
  b) Turn file into .dae Using blender (Maybe only STL can be used, not sure)
  c) Inserting model file 
      directory : /home/.gazebo/models (ctrl+H)
      mkdir ?? 
      Put mesh, sdf, config file here
      Reference : (https://ola-page.tistory.com/2)
  d) Making SDF file
  
        <Basic Format for CAD import>

<?xml version="1.0"?>
<sdf version="1.5">
  <model name="box">
    <pose>0 0 0  0 0 0</pose>
    <static>true</static>
    <link name="body">
      <visual name="visual">
        <geometry>
          <mesh>
             <scale> 0.3 0.3 0.3 </scale>>
             <uri>model://box/box.dae</uri>
          </mesh>
        </geometry>
      </visual>
    </link>
  </model>
</sdf>

  e) Making config file
  
          <Basic format>

<?xml version="1.0"?>

<model>
  <name>box</name>
  <version>1.0</version>
  <sdf version="1.5">model.sdf</sdf>

  <author>
    <name>Optional: YOUR NAME</name>
    <email>Optional: YOUR EMAIL</email>
  </author>


</model>

2. killing gazebo with terminal : killall -9 gazebo & killall -9 gzserver  & killall -9 gzclient

    add : alias killgazebo="killall -9 gazebo & killall -9 gzserver  & killall -9 gzclient"
    
    
3. When running Gazebo, "  Can't open /home/??/catkin_ws/devel/share/gazebo/setup.sh "  error 
    Go to cd /opt/ros/noetic/lib/gazebo_ros/???(scripts on the terminal)
    and fix line(sudo gedit 'script name') " setup_path=$(pkg-config --variable=prefix gazebo)/share/gazebo/ " into " setup_path=/usr/share/gazebo "