Hi,

I am interested in having a North-East-Down inertial frame in Gazebo. AFAIK this is not possible by just setting an option, and this question remains unanswered.

As a workaround I was trying to flip the camera 180 deg around its X axis and spawn objects in negative Z, but whenever they are below the ground plane they are switched to the positive Z in the next iteration. I tried flipping 180 deg also the ground plane but still the same behavior. Also, the camera gets moved to a "normal"position whenever I try to move it (zoom works OK though, and FPS camera kind of work as well).

Can anybody give me some advice on how to achieve this? Thank you!

EDIT: I added the world I am using to test, contains a cylinder, a inverted gravity and cameras, and a ground plane also rotated (in case it makes any difference, because the same behavior is noticed without flipping the ground plane.

<?xml version="1.0" ?>
<sdf version="1.5">
<world name="test_world">
    <physics type="ode">
        <gravity>0.0 0.0 9.81</gravity>
        <ode>
            <solver>
                <type>quick</type>
                <iters>50</iters>
                <sor>0.8</sor>
            </solver>
        </ode>
        <real_time_update_rate>1000</real_time_update_rate>
        <max_step_size>0.001</max_step_size>
    </physics>

        <gui>
  <camera name="user_camera">
    <pose>1 0 -1 3.141592 0 0</pose>
  </camera>
</gui>

<model name='unit_cylinder_1'>
      <pose>0 0 -1.5 0 0 0</pose>
      <link name='link'>
        <inertial>
          <mass>1</mass>
          <inertia>
            <ixx>1</ixx>
            <ixy>0</ixy>
            <ixz>0</ixz>
            <iyy>1</iyy>
            <iyz>0</iyz>
            <izz>1</izz>
          </inertia>
        </inertial>
        <collision name='collision'>
          <geometry>
            <cylinder>
              <radius>0.5</radius>
              <length>1</length>
            </cylinder>
          </geometry>
          <max_contacts>10</max_contacts>
        </collision>
        <visual name='visual'>
          <geometry>
            <cylinder>
              <radius>0.5</radius>
              <length>1</length>
            </cylinder>
          </geometry>
          <material>
            <script>
              <uri>file://media/materials/scripts/gazebo.material</uri>
              <name>Gazebo/Grey</name>
            </script>
          </material>
        </visual>
        <self_collide>0</self_collide>
        <kinematic>0</kinematic>
      </link>
    </model>

    <include>
         <pose>0 0 0 3.141592 0 0</pose>
        <uri>model://ground_plane</uri>
    </include>
</world>

<?xml version="1.0" ?>
<sdf version="1.5">
<world name="test_world">
  <physics type="ode">
      <gravity>0.0 0.0 9.81</gravity>
  </physics>

  <gui>
    <camera name="user_camera">
      <pose>-4.7 0 -1.6 3.141592 0 0</pose>
    </camera>
  </gui>

  <light type="directional" name="sun">
    <cast_shadows>true</cast_shadows>
    <pose>0 0 10 3.14 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='unit_cylinder_1'>
    <pose>0 0 -1.5 0 0 0</pose>
    <link name='link'>
      <collision name='collision'>
        <geometry>
          <cylinder>
            <radius>0.5</radius>
            <length>1</length>
          </cylinder>
        </geometry>
      </collision>
      <visual name='visual'>
        <geometry>
          <cylinder>
            <radius>0.5</radius>
            <length>1</length>
          </cylinder>
        </geometry>
      </visual>
    </link>
  </model>

  <model name='ground_box'>
   <static>1</static>
    <link name='link'>
      <collision name='collision'>
        <geometry>
          <box>
            <size>100 100 1</size>
          </box>
        </geometry>
      </collision>
      <visual name='visual'>
        <geometry>
          <box>
            <size>100 100 1</size>
          </box>
        </geometry>
      </visual>
    </link>
  </model>
</world>
</sdf>