<?xml version='1.0'?>
<sdf version="1.4">
  <model name="frc_2014_ball_blue">
    <pose>0 0 0.5 0 0 0</pose>
    <link name="ball">
      <inertial>
        <!-- rough estimate: 1.5 kg spherical shell, radius 30 cm -->
        <mass>1.3671</mass>
        <inertia>
          <!-- xx = yy = zz = 2/5 * mass * radius^2 -->
          <ixx>0.00508</ixx>
          <ixy>0.00</ixy>
          <ixz>0.00</ixz>
          <iyy>0.00508</iyy>
          <iyz>0.00</iyz>
          <izz>0.00508</izz>
        </inertia>
      </inertial>
      <collision name="collision">
        <geometry>
          <sphere>
            <radius>0.3048</radius>
          </sphere>
        </geometry>
        <surface>
          <bounce>
            <restitution_coefficient>0.8</restitution_coefficient>
            <threshold>0</threshold>
          </bounce>
          <contact>
            <ode>
              <max_vel>1000</max_vel>
              <min_depth>0</min_depth>
            </ode>
          </contact>
        </surface>
      </collision>
      <visual name="visual">
        <geometry>
          <sphere>
            <radius>0.3048</radius>
          </sphere>
        </geometry>
        <material>
          <script>
            <uri>file://media/materials/scripts/gazebo.material</uri>
            <name>Gazebo/Blue</name>
          </script>
        </material>
      </visual>
      <!-- this is a minimalist way to model the ball's rolling friction -->
      <velocity_decay>
        <linear>0.0</linear>
        <angular>0.01</angular>
      </velocity_decay>
    </link>
  </model>
</sdf>
