quadcopter_demo.sdf

<?xml version="1.0" ?>
<!--
  Quadcopter sensor demo for gz-camera-stream.

  X3 UAV with velocity control, forward and downward cameras,
  ground objects from Gazebo Fuel, and a tower overview camera.
  All camera feeds are streamable via the CameraStream plugin.

  Launch headless:
    GZ_SIM_SYSTEM_PLUGIN_PATH=/opt/homebrew/lib \
      gz sim -s -r --headless-rendering quadcopter_demo.sdf -v 4

  Fly the quadcopter:
    gz topic -t "/X3/gazebo/command/twist" -m gz.msgs.Twist \
      -p "linear: {z: 0.5}"

  Hover:
    gz topic -t "/X3/gazebo/command/twist" -m gz.msgs.Twist -p " "

  Or run the patrol script:
    ./fly_patrol.sh
-->
<sdf version="1.9">
  <world name="quadcopter_demo">

    <physics name="4ms" type="ignored">
      <max_step_size>0.004</max_step_size>
      <real_time_factor>1.0</real_time_factor>
    </physics>

    <!-- Core system plugins -->
    <plugin
        filename="gz-sim-physics-system"
        name="gz::sim::systems::Physics">
    </plugin>
    <plugin
        filename="gz-sim-user-commands-system"
        name="gz::sim::systems::UserCommands">
    </plugin>
    <plugin
        filename="gz-sim-scene-broadcaster-system"
        name="gz::sim::systems::SceneBroadcaster">
    </plugin>
    <plugin
        filename="gz-sim-sensors-system"
        name="gz::sim::systems::Sensors">
      <render_engine>ogre2</render_engine>
    </plugin>

    <!-- WebSocket server for viewer.html -->
    <plugin
        filename="gz-sim-websocket-server-system"
        name="gz::sim::systems::WebsocketServer">
      <publication_hz>30</publication_hz>
      <port>9002</port>
      <max_connections>-1</max_connections>
    </plugin>

    <!-- CameraStream - H.264 encoding to MediaMTX -->
    <plugin
        filename="gz-sim-camera-stream-system"
        name="gz::sim::systems::CameraStream">
      <topic>/stream/control</topic>
      <default_bitrate>4000000</default_bitrate>
      <default_fps>30</default_fps>
    </plugin>

    <!-- Scene -->
    <scene>
      <ambient>0.5 0.5 0.5 1.0</ambient>
      <background>0.3 0.5 0.8 1.0</background>
      <grid>false</grid>
    </scene>

    <!-- Sun -->
    <light type="directional" name="sun">
      <cast_shadows>true</cast_shadows>
      <pose>0 0 50 0 0 0</pose>
      <diffuse>1.0 0.95 0.9 1</diffuse>
      <specular>0.5 0.5 0.5 1</specular>
      <attenuation>
        <range>1000</range>
        <constant>0.9</constant>
        <linear>0.01</linear>
        <quadratic>0.001</quadratic>
      </attenuation>
      <direction>-0.5 0.3 -0.9</direction>
    </light>

    <!-- Ground plane -->
    <model name="ground_plane">
      <static>true</static>
      <link name="link">
        <collision name="collision">
          <geometry>
            <plane>
              <normal>0 0 1</normal>
              <size>200 200</size>
            </plane>
          </geometry>
        </collision>
        <visual name="visual">
          <geometry>
            <plane>
              <normal>0 0 1</normal>
              <size>200 200</size>
            </plane>
          </geometry>
          <material>
            <ambient>0.45 0.55 0.35 1</ambient>
            <diffuse>0.45 0.55 0.35 1</diffuse>
            <specular>0.1 0.1 0.1 1</specular>
          </material>
        </visual>
      </link>
    </model>

    <!-- Landing pad -->
    <model name="landing_pad">
      <static>true</static>
      <pose>0 0 0.01 0 0 0</pose>
      <link name="link">
        <visual name="pad">
          <geometry>
            <cylinder>
              <radius>1.5</radius>
              <length>0.02</length>
            </cylinder>
          </geometry>
          <material>
            <ambient>0.3 0.3 0.3 1</ambient>
            <diffuse>0.3 0.3 0.3 1</diffuse>
          </material>
        </visual>
        <visual name="h_bar1">
          <pose>0 0 0.02 0 0 0</pose>
          <geometry>
            <box><size>0.15 1.0 0.01</size></box>
          </geometry>
          <material>
            <ambient>0.9 0.9 0.0 1</ambient>
            <diffuse>0.9 0.9 0.0 1</diffuse>
          </material>
        </visual>
        <visual name="h_bar2">
          <pose>0 0 0.02 0 0 1.5708</pose>
          <geometry>
            <box><size>0.15 0.6 0.01</size></box>
          </geometry>
          <material>
            <ambient>0.9 0.9 0.0 1</ambient>
            <diffuse>0.9 0.9 0.0 1</diffuse>
          </material>
        </visual>
      </link>
    </model>

    <!-- ============================================================ -->
    <!--  X3 UAV Quadcopter from Gazebo Fuel                          -->
    <!-- ============================================================ -->
    <include>
      <uri>https://fuel.gazebosim.org/1.0/OpenRobotics/models/X3 UAV/4</uri>
      <name>x3_uav</name>
      <pose>0 0 0.2 0 0 0</pose>

      <!-- Rotor 0 (CCW) -->
      <plugin
        filename="gz-sim-multicopter-motor-model-system"
        name="gz::sim::systems::MulticopterMotorModel">
        <robotNamespace>X3</robotNamespace>
        <jointName>X3/rotor_0_joint</jointName>
        <linkName>X3/rotor_0</linkName>
        <turningDirection>ccw</turningDirection>
        <timeConstantUp>0.0125</timeConstantUp>
        <timeConstantDown>0.025</timeConstantDown>
        <maxRotVelocity>800.0</maxRotVelocity>
        <motorConstant>8.54858e-06</motorConstant>
        <momentConstant>0.016</momentConstant>
        <commandSubTopic>gazebo/command/motor_speed</commandSubTopic>
        <actuator_number>0</actuator_number>
        <rotorDragCoefficient>8.06428e-05</rotorDragCoefficient>
        <rollingMomentCoefficient>1e-06</rollingMomentCoefficient>
        <motorSpeedPubTopic>motor_speed/0</motorSpeedPubTopic>
        <rotorVelocitySlowdownSim>10</rotorVelocitySlowdownSim>
        <motorType>velocity</motorType>
      </plugin>

      <!-- Rotor 1 (CCW) -->
      <plugin
        filename="gz-sim-multicopter-motor-model-system"
        name="gz::sim::systems::MulticopterMotorModel">
        <robotNamespace>X3</robotNamespace>
        <jointName>X3/rotor_1_joint</jointName>
        <linkName>X3/rotor_1</linkName>
        <turningDirection>ccw</turningDirection>
        <timeConstantUp>0.0125</timeConstantUp>
        <timeConstantDown>0.025</timeConstantDown>
        <maxRotVelocity>800.0</maxRotVelocity>
        <motorConstant>8.54858e-06</motorConstant>
        <momentConstant>0.016</momentConstant>
        <commandSubTopic>gazebo/command/motor_speed</commandSubTopic>
        <actuator_number>1</actuator_number>
        <rotorDragCoefficient>8.06428e-05</rotorDragCoefficient>
        <rollingMomentCoefficient>1e-06</rollingMomentCoefficient>
        <motorSpeedPubTopic>motor_speed/1</motorSpeedPubTopic>
        <rotorVelocitySlowdownSim>10</rotorVelocitySlowdownSim>
        <motorType>velocity</motorType>
      </plugin>

      <!-- Rotor 2 (CW) -->
      <plugin
        filename="gz-sim-multicopter-motor-model-system"
        name="gz::sim::systems::MulticopterMotorModel">
        <robotNamespace>X3</robotNamespace>
        <jointName>X3/rotor_2_joint</jointName>
        <linkName>X3/rotor_2</linkName>
        <turningDirection>cw</turningDirection>
        <timeConstantUp>0.0125</timeConstantUp>
        <timeConstantDown>0.025</timeConstantDown>
        <maxRotVelocity>800.0</maxRotVelocity>
        <motorConstant>8.54858e-06</motorConstant>
        <momentConstant>0.016</momentConstant>
        <commandSubTopic>gazebo/command/motor_speed</commandSubTopic>
        <actuator_number>2</actuator_number>
        <rotorDragCoefficient>8.06428e-05</rotorDragCoefficient>
        <rollingMomentCoefficient>1e-06</rollingMomentCoefficient>
        <motorSpeedPubTopic>motor_speed/2</motorSpeedPubTopic>
        <rotorVelocitySlowdownSim>10</rotorVelocitySlowdownSim>
        <motorType>velocity</motorType>
      </plugin>

      <!-- Rotor 3 (CW) -->
      <plugin
        filename="gz-sim-multicopter-motor-model-system"
        name="gz::sim::systems::MulticopterMotorModel">
        <robotNamespace>X3</robotNamespace>
        <jointName>X3/rotor_3_joint</jointName>
        <linkName>X3/rotor_3</linkName>
        <turningDirection>cw</turningDirection>
        <timeConstantUp>0.0125</timeConstantUp>
        <timeConstantDown>0.025</timeConstantDown>
        <maxRotVelocity>800.0</maxRotVelocity>
        <motorConstant>8.54858e-06</motorConstant>
        <momentConstant>0.016</momentConstant>
        <commandSubTopic>gazebo/command/motor_speed</commandSubTopic>
        <actuator_number>3</actuator_number>
        <rotorDragCoefficient>8.06428e-05</rotorDragCoefficient>
        <rollingMomentCoefficient>1e-06</rollingMomentCoefficient>
        <motorSpeedPubTopic>motor_speed/3</motorSpeedPubTopic>
        <rotorVelocitySlowdownSim>10</rotorVelocitySlowdownSim>
        <motorType>velocity</motorType>
      </plugin>

      <!-- Velocity controller - accepts Twist commands -->
      <plugin
        filename="gz-sim-multicopter-control-system"
        name="gz::sim::systems::MulticopterVelocityControl">
        <robotNamespace>X3</robotNamespace>
        <commandSubTopic>gazebo/command/twist</commandSubTopic>
        <enableSubTopic>enable</enableSubTopic>
        <comLinkName>X3/base_link</comLinkName>
        <velocityGain>2.7 2.7 2.7</velocityGain>
        <attitudeGain>2 3 0.15</attitudeGain>
        <angularRateGain>0.4 0.52 0.18</angularRateGain>
        <maximumLinearAcceleration>2 2 2</maximumLinearAcceleration>
        <rotorConfiguration>
          <rotor>
            <jointName>X3/rotor_0_joint</jointName>
            <forceConstant>8.54858e-06</forceConstant>
            <momentConstant>0.016</momentConstant>
            <direction>1</direction>
          </rotor>
          <rotor>
            <jointName>X3/rotor_1_joint</jointName>
            <forceConstant>8.54858e-06</forceConstant>
            <momentConstant>0.016</momentConstant>
            <direction>1</direction>
          </rotor>
          <rotor>
            <jointName>X3/rotor_2_joint</jointName>
            <forceConstant>8.54858e-06</forceConstant>
            <momentConstant>0.016</momentConstant>
            <direction>-1</direction>
          </rotor>
          <rotor>
            <jointName>X3/rotor_3_joint</jointName>
            <forceConstant>8.54858e-06</forceConstant>
            <momentConstant>0.016</momentConstant>
            <direction>-1</direction>
          </rotor>
        </rotorConfiguration>
      </plugin>

      <!-- Odometry publisher -->
      <plugin
        filename="gz-sim-odometry-publisher-system"
        name="gz::sim::systems::OdometryPublisher">
        <dimensions>3</dimensions>
      </plugin>
    </include>

    <!-- ============================================================ -->
    <!--  Sensor pod - attached to UAV via fixed joint                 -->
    <!-- ============================================================ -->
    <model name="sensor_pod">
      <pose>0 0 0.2 0 0 0</pose>
      <link name="pod_link">
        <inertial>
          <mass>0.05</mass>
          <inertia>
            <ixx>0.0001</ixx><iyy>0.0001</iyy><izz>0.0001</izz>
          </inertia>
        </inertial>

        <!-- Front-facing camera -->
        <sensor name="front_camera" type="camera">
          <pose>0.15 0 0 0 0 0</pose>
          <camera>
            <horizontal_fov>1.39626</horizontal_fov>
            <image>
              <width>1280</width>
              <height>720</height>
            </image>
            <clip>
              <near>0.1</near>
              <far>500</far>
            </clip>
          </camera>
          <always_on>1</always_on>
          <update_rate>30</update_rate>
          <visualize>false</visualize>
          <topic>X3/front_camera</topic>
        </sensor>

        <!-- Downward-facing camera -->
        <sensor name="down_camera" type="camera">
          <pose>0 0 -0.05 0 1.5708 0</pose>
          <camera>
            <horizontal_fov>1.39626</horizontal_fov>
            <image>
              <width>640</width>
              <height>480</height>
            </image>
            <clip>
              <near>0.1</near>
              <far>500</far>
            </clip>
          </camera>
          <always_on>1</always_on>
          <update_rate>15</update_rate>
          <visualize>false</visualize>
          <topic>X3/down_camera</topic>
        </sensor>
      </link>
    </model>

    <!-- Attach sensor pod to X3 UAV body -->
    <joint name="sensor_pod_joint" type="fixed">
      <parent>x3_uav::X3/base_link</parent>
      <child>sensor_pod::pod_link</child>
    </joint>

    <!-- ============================================================ -->
    <!--  Tower overview camera                                        -->
    <!-- ============================================================ -->
    <model name="tower_camera">
      <static>true</static>
      <pose>-15 -15 12 0 0.4 0.78</pose>
      <link name="link">
        <visual name="visual">
          <geometry><box><size>0.15 0.15 0.15</size></box></geometry>
          <material>
            <ambient>0.2 0.2 0.2 1</ambient>
            <diffuse>0.2 0.2 0.2 1</diffuse>
          </material>
        </visual>
        <sensor name="tower_camera" type="camera">
          <camera>
            <horizontal_fov>1.2</horizontal_fov>
            <image>
              <width>1280</width>
              <height>720</height>
            </image>
            <clip>
              <near>0.5</near>
              <far>1000</far>
            </clip>
          </camera>
          <always_on>1</always_on>
          <update_rate>30</update_rate>
          <visualize>false</visualize>
          <topic>tower_camera</topic>
        </sensor>
      </link>
    </model>

    <!-- Camera tower structure -->
    <model name="tower_structure">
      <static>true</static>
      <pose>-15 -15 0 0 0 0</pose>
      <link name="link">
        <visual name="pole">
          <pose>0 0 6 0 0 0</pose>
          <geometry>
            <cylinder><radius>0.08</radius><length>12</length></cylinder>
          </geometry>
          <material>
            <ambient>0.5 0.5 0.5 1</ambient>
            <diffuse>0.5 0.5 0.5 1</diffuse>
          </material>
        </visual>
      </link>
    </model>

    <!-- ============================================================ -->
    <!--  Ground objects from Gazebo Fuel                               -->
    <!-- ============================================================ -->

    <include>
      <uri>https://fuel.gazebosim.org/1.0/OpenRobotics/models/Gas Station</uri>
      <name>gas_station</name>
      <pose>20 10 0 0 0 0.5</pose>
    </include>

    <include>
      <uri>https://fuel.gazebosim.org/1.0/OpenRobotics/models/Hatchback blue</uri>
      <name>car_1</name>
      <pose>15 -5 0 0 0 1.2</pose>
    </include>

    <include>
      <uri>https://fuel.gazebosim.org/1.0/OpenRobotics/models/SUV</uri>
      <name>suv_1</name>
      <pose>22 8 0 0 0 -0.3</pose>
    </include>

    <include>
      <uri>https://fuel.gazebosim.org/1.0/OpenRobotics/models/Pickup</uri>
      <name>pickup_1</name>
      <pose>-10 15 0 0 0 2.0</pose>
    </include>

    <!-- Simple structures for visual interest -->
    <model name="warehouse">
      <static>true</static>
      <pose>-20 20 0 0 0 0.3</pose>
      <link name="link">
        <visual name="walls">
          <pose>0 0 3 0 0 0</pose>
          <geometry><box><size>12 8 6</size></box></geometry>
          <material>
            <ambient>0.6 0.6 0.55 1</ambient>
            <diffuse>0.6 0.6 0.55 1</diffuse>
          </material>
        </visual>
        <visual name="roof">
          <pose>0 0 6.1 0 0 0</pose>
          <geometry><box><size>12.5 8.5 0.2</size></box></geometry>
          <material>
            <ambient>0.4 0.3 0.25 1</ambient>
            <diffuse>0.4 0.3 0.25 1</diffuse>
          </material>
        </visual>
        <collision name="collision">
          <pose>0 0 3 0 0 0</pose>
          <geometry><box><size>12 8 6</size></box></geometry>
        </collision>
      </link>
    </model>

    <model name="water_tower">
      <static>true</static>
      <pose>25 -20 0 0 0 0</pose>
      <link name="link">
        <visual name="legs">
          <pose>0 0 5 0 0 0</pose>
          <geometry><cylinder><radius>0.15</radius><length>10</length></cylinder></geometry>
          <material>
            <ambient>0.5 0.5 0.5 1</ambient>
            <diffuse>0.5 0.5 0.5 1</diffuse>
          </material>
        </visual>
        <visual name="tank">
          <pose>0 0 11 0 0 0</pose>
          <geometry><cylinder><radius>2.0</radius><length>3</length></cylinder></geometry>
          <material>
            <ambient>0.3 0.4 0.6 1</ambient>
            <diffuse>0.3 0.4 0.6 1</diffuse>
          </material>
        </visual>
        <visual name="cap">
          <pose>0 0 12.6 0 0 0</pose>
          <geometry><sphere><radius>2.1</radius></sphere></geometry>
          <material>
            <ambient>0.3 0.4 0.6 1</ambient>
            <diffuse>0.3 0.4 0.6 1</diffuse>
          </material>
        </visual>
      </link>
    </model>

    <!-- Crates near landing pad -->
    <model name="crate_1">
      <static>true</static>
      <pose>3 2 0.4 0 0 0.2</pose>
      <link name="link">
        <visual name="visual">
          <geometry><box><size>0.8 0.8 0.8</size></box></geometry>
          <material>
            <ambient>0.6 0.45 0.25 1</ambient>
            <diffuse>0.6 0.45 0.25 1</diffuse>
          </material>
        </visual>
      </link>
    </model>

    <model name="crate_2">
      <static>true</static>
      <pose>3.5 2.8 0.3 0 0 -0.4</pose>
      <link name="link">
        <visual name="visual">
          <geometry><box><size>0.6 0.6 0.6</size></box></geometry>
          <material>
            <ambient>0.55 0.4 0.2 1</ambient>
            <diffuse>0.55 0.4 0.2 1</diffuse>
          </material>
        </visual>
      </link>
    </model>

    <model name="crate_3">
      <static>true</static>
      <pose>3.2 2.3 1.0 0 0 0.6</pose>
      <link name="link">
        <visual name="visual">
          <geometry><box><size>0.5 0.5 0.5</size></box></geometry>
          <material>
            <ambient>0.5 0.35 0.15 1</ambient>
            <diffuse>0.5 0.35 0.15 1</diffuse>
          </material>
        </visual>
      </link>
    </model>

  </world>
</sdf>