<?xml version="1.0" ?>
<sdf version="1.6">
  <world name="levels">
    <physics name="fast" type="ignored">
      <real_time_factor>0</real_time_factor>
    </physics>

    <plugin
      filename="ignition-gazebo-scene-broadcaster-system"
      name="ignition::gazebo::systems::SceneBroadcaster">
    </plugin>

    <light type="directional" name="sun">
      <cast_shadows>true</cast_shadows>
      <pose>0 0 10 0 0 0</pose>
      <diffuse>0.8 0.8 0.8 1</diffuse>
      <specular>0.2 0.2 0.2 1</specular>
      <attenuation>
        <range>1000</range>
        <constant>0.9</constant>
        <linear>0.01</linear>
        <quadratic>0.001</quadratic>
      </attenuation>
      <direction>-0.5 0.1 -0.9</direction>
    </light>

    <model name="sphere">
      <pose>0 0 0 0 0 0</pose>
      <static>true</static>
      <link name="sphere_link">
        <visual name="visual">
          <geometry>
            <sphere>1</sphere>
          </geometry>
        </visual>
        <collision name="collision">
          <geometry>
            <sphere>1</sphere>
          </geometry>
        </collision>
      </link>
    </model>

    <model name="box">
      <pose>0 0 0 0 0 0</pose>
      <static>true</static>
      <link name="box_link">
        <visual name="visual">
          <geometry>
            <box>1 1 1</box>
          </geometry>
        </visual>
        <collision name="collision">
          <geometry>
            <box>1 1 1</box>
          </geometry>
        </collision>
      </link>
    </model>

    <!-- Grid tiles -->

    <model name="tile_0">
      <pose>40 -20 0 0 0 3.141592653589793</pose>
      <static>true</static>
      <link name="link">

        <collision name="collision_0">
          <pose>0 0 -0.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_0">
          <pose>0 0 -0.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_1">
          <pose>0 0 4.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_1">
          <pose>0 0 4.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_2">
          <pose>0 0 -0.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_2">
          <pose>0 0 -0.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_3">
          <pose>0 0 4.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_3">
          <pose>0 0 4.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_4">
          <pose>-2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_4">
          <pose>-2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_5">
          <pose>2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_5">
          <pose>2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_6">
          <pose>-2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_6">
          <pose>-2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_7">
          <pose>2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_7">
          <pose>2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_8">
          <pose>6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_8">
          <pose>6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_9">
          <pose>-6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_9">
          <pose>-6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_10">
          <pose>6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_10">
          <pose>6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_11">
          <pose>-6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_11">
          <pose>-6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

      </link>
    </model>

    <model name="tile_1">
      <pose>40 0 0 0 0 0</pose>
      <static>true</static>
      <link name="link">

        <collision name="collision_0">
          <pose>0 0 -0.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_0">
          <pose>0 0 -0.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_1">
          <pose>0 0 4.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_1">
          <pose>0 0 4.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_2">
          <pose>0 0 -0.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_2">
          <pose>0 0 -0.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_3">
          <pose>0 0 4.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_3">
          <pose>0 0 4.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_4">
          <pose>-2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_4">
          <pose>-2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_5">
          <pose>2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_5">
          <pose>2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_6">
          <pose>-2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_6">
          <pose>-2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_7">
          <pose>2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_7">
          <pose>2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_8">
          <pose>6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_8">
          <pose>6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_9">
          <pose>-6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_9">
          <pose>-6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_10">
          <pose>6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_10">
          <pose>6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_11">
          <pose>-6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_11">
          <pose>-6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

      </link>
    </model>

    <model name="tile_2">
      <pose>40 20 0 0 0 -1.5707963267948966</pose>
      <static>true</static>
      <link name="link">

        <collision name="collision_0">
          <pose>0 0 -0.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_0">
          <pose>0 0 -0.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_1">
          <pose>0 0 4.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_1">
          <pose>0 0 4.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_2">
          <pose>0 0 -0.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_2">
          <pose>0 0 -0.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_3">
          <pose>0 0 4.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_3">
          <pose>0 0 4.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_4">
          <pose>-2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_4">
          <pose>-2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_5">
          <pose>2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_5">
          <pose>2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_6">
          <pose>-2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_6">
          <pose>-2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_7">
          <pose>2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_7">
          <pose>2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_8">
          <pose>6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_8">
          <pose>6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_9">
          <pose>-6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_9">
          <pose>-6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_10">
          <pose>6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_10">
          <pose>6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_11">
          <pose>-6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_11">
          <pose>-6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

      </link>
    </model>

    <model name="tile_3">
      <pose>60 -20 0 0 0 0</pose>
      <static>true</static>
      <link name="link">

        <collision name="collision_0">
          <pose>0 0 -0.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_0">
          <pose>0 0 -0.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_1">
          <pose>0 0 4.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_1">
          <pose>0 0 4.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_2">
          <pose>0 0 -0.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_2">
          <pose>0 0 -0.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_3">
          <pose>0 0 4.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_3">
          <pose>0 0 4.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_4">
          <pose>-2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_4">
          <pose>-2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_5">
          <pose>2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_5">
          <pose>2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_6">
          <pose>-2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_6">
          <pose>-2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_7">
          <pose>2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_7">
          <pose>2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_8">
          <pose>6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_8">
          <pose>6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_9">
          <pose>-6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_9">
          <pose>-6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_10">
          <pose>6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_10">
          <pose>6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_11">
          <pose>-6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_11">
          <pose>-6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

      </link>
    </model>

    <model name="tile_4">
      <pose>60 0 0 0 0 3.141592653589793</pose>
      <static>true</static>
      <link name="link">

        <collision name="collision_0">
          <pose>0 0 -0.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_0">
          <pose>0 0 -0.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_1">
          <pose>0 0 4.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_1">
          <pose>0 0 4.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_2">
          <pose>0 0 -0.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_2">
          <pose>0 0 -0.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_3">
          <pose>0 0 4.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_3">
          <pose>0 0 4.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_4">
          <pose>-2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_4">
          <pose>-2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_5">
          <pose>2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_5">
          <pose>2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_6">
          <pose>-2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_6">
          <pose>-2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_7">
          <pose>2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_7">
          <pose>2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_8">
          <pose>6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_8">
          <pose>6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_9">
          <pose>-6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_9">
          <pose>-6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_10">
          <pose>6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_10">
          <pose>6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_11">
          <pose>-6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_11">
          <pose>-6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

      </link>
    </model>

    <model name="tile_5">
      <pose>60 20 0 0 0 3.141592653589793</pose>
      <static>true</static>
      <link name="link">

        <collision name="collision_0">
          <pose>0 0 -0.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_0">
          <pose>0 0 -0.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_1">
          <pose>0 0 4.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_1">
          <pose>0 0 4.25 0 0 0</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_2">
          <pose>0 0 -0.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_2">
          <pose>0 0 -0.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_3">
          <pose>0 0 4.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_3">
          <pose>0 0 4.25 0 0 1.57</pose>
          <geometry>
            <box><size>5 20 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_4">
          <pose>-2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_4">
          <pose>-2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_5">
          <pose>2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_5">
          <pose>2.5 6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_6">
          <pose>-2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_6">
          <pose>-2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_7">
          <pose>2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_7">
          <pose>2.5 -6.25 2 3.14 -1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_8">
          <pose>6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_8">
          <pose>6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_9">
          <pose>-6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_9">
          <pose>-6.25 2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_10">
          <pose>6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_10">
          <pose>6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

        <collision name="collision_11">
          <pose>-6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
        </collision>
        <visual name="visual_11">
          <pose>-6.25 -2.5 2 1.57 1.57 0</pose>
          <geometry>
            <box><size>5 7.5 0.5</size></box>
          </geometry>
          <material>
            <ambient>0 0 1 0.8</ambient>
            <diffuse>0 0 1 0.8</diffuse>
            <specular>1 1 1 0.8</specular>
          </material>
        </visual>

      </link>
    </model>

  <plugin name="ignition::gazebo" filename="dummy">
    <level name="level1">
      <pose>40 0 2.5 0 0 0</pose>
      <geometry>
        <box>
          <size>30 30 10</size>
        </box>
      </geometry>
      <buffer>5</buffer>
      <ref>tile_1</ref>
    </level>

    <level name="level2">
      <pose>40 20 2.5 0 0 0</pose>
      <geometry>
        <box>
          <size>30 30 10</size>
        </box>
      </geometry>
      <buffer>5</buffer>
      <ref>tile_2</ref>
    </level>

    <level name="level3">
      <pose>60 -20 2.5 0 0 0</pose>
      <geometry>
        <box>
          <size>30 30 10</size>
        </box>
      </geometry>
      <buffer>5</buffer>
      <ref>tile_3</ref>
    </level>

    <level name="level4">
      <pose>60 0 2.5 0 0 0</pose>
      <geometry>
        <box>
          <size>30 30 10</size>
        </box>
      </geometry>
      <buffer>5</buffer>
      <ref>tile_4</ref>
    </level>

    <level name="level5">
      <pose>60 20 2.5 0 0 0</pose>
      <geometry>
        <box>
          <size>30 30 10</size>
        </box>
      </geometry>
      <buffer>5</buffer>
      <ref>tile_5</ref>
    </level>

  </plugin>

  </world>
</sdf>
