Example added for Lighter-than-air envelope

Signed-off-by: henrykotze <henry@flycloudline.com>

Author: henrykotze

examples/worlds/lighter_than_air_blimp.sdf

@@ -0,0 +1,78 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <world name="blimp">
+
+   <physics name="1ms" type="ode">
+      <max_step_size>0.001</max_step_size>
+      <!-- Zero to run as fast as possible -->
+      <real_time_factor>1</real_time_factor>
+    </physics>
+
+    <gravity>0 0 -9.81</gravity>
+
+    <plugin
+      filename="ignition-gazebo-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-buoyancy-system"
+      name="gz::sim::systems::Buoyancy">
+      <uniform_fluid_density>1.097</uniform_fluid_density>
+    </plugin>
+
+    <light type="directional" name="sun">
+      <cast_shadows>true</cast_shadows>
+      <pose>0 0 10 0 0 0</pose>
+      <diffuse>1 1 1 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 0.1 -0.9</direction>
+    </light>
+
+    <model name="ground_plane">
+      <static>true</static>
+      <link name="link">
+        <collision name="collision">
+          <geometry>
+            <plane>
+              <normal>0 0 1</normal>
+              <size>100 100</size>
+            </plane>
+          </geometry>
+        </collision>
+        <visual name="visual">
+          <geometry>
+            <plane>
+              <normal>0 0 1</normal>
+              <size>100 100</size>
+            </plane>
+          </geometry>
+          <material>
+            <ambient>0.8 0.8 0.8 1</ambient>
+            <diffuse>0.8 0.8 0.8 1</diffuse>
+            <specular>0.8 0.8 0.8 1</specular>
+          </material>
+        </visual>
+      </link>
+    </model>
+    <include>
+      <uri>
+        https://fuel.gazebosim.org/1.0/hkotze/models/airship
+      </uri>
+    </include>
+  </world>
+</sdf>

test/worlds/CMakeLists.txt

@@ -6,4 +6,3 @@ configure_file (environmental_data.sdf.in ${PROJECT_BINARY_DIR}/test/worlds/envi
 
 configure_file (environmental_sensor.sdf.in ${PROJECT_BINARY_DIR}/test/worlds/environmental_sensor.sdf)
 configure_file (hydrodynamics.sdf.in ${PROJECT_BINARY_DIR}/test/worlds/hydrodynamics.sdf)
-configure_file (lighter_than_air_dynamics.sdf.in ${PROJECT_BINARY_DIR}/test/worlds/lighter_than_air_dynamics.sdf)