Loading another model from an SDF ros2 humble

Question

I'm trying to include another sdf with , I can load it properly with an absolute path to the file but I want to make it a relative path. Structure is as follows:

• package
  • src
  • models
  • worlds
    • model_1.sdf
    • model_2.sdf

For example I want to load model 2 inside of model 1. I can only find examples which are outdated, if anybody can point me in the right direction, that would be appreciated.

Using ROS2 humble with gazebo fortress

Thanks.

Answer 1

as I am not able to comment, I am writing my suggestion in answer section.

I am assuming that you want to add the same model in the sdf. You can include the models using the merge tag in sdf. Just for an example:

<!-- <include>
  <uri>
    https://fuel.gazebosim.org/1.0/OpenRobotics/models/Coke Can
  </uri>
</include>

<include>
  <merge>true</merge>
  <name>my_can</name>
  <uri>
    https://fuel.gazebosim.org/1.0/OpenRobotics/models/Coke Can
  </uri>
  <pose>0 0 1 0 0 0 </pose>
</include> -->

You can refer the sdformat documentation and different tags information here: http://sdformat.org/spec?ver=1.10&elem=model

Answer 2

To include models in the SDF file, you need to write the models directory path to the environment variable IGN_GAZEBO_RESOURCE_PATH, which would allow it to be visible. After which, you can reference models in your SDF with the following syntax:

<include>
   <uri>model://aws_robomaker_warehouse_RoofB_01</uri>
</include>

Note: Your models have to be well-defined with a config file. For reference example you can check out this repository. It includes models defined in the repository in its world SDF.

Answer 3

you can post refer to this Post, if u need any help, let me know. I was able to do it.

Steps to Follow:

1.Create a Models Folder in your Directory(package file) and store the sdf file there. I have created a single Folder named Box inside the Models File

• Models
  • Box
    • model.config
    • model.sdf
    • meshes(folder)
      • mesh1.dae
      • mesh2.stl
      • mesh3.stl

below is the info inside present in the all the files.

a. Model.config file

  <?xml version="1.0"?>
  <model>
    <name>Box</name>
    <version>1.0</version>
    <sdf version='1.6'>model.sdf</sdf>
 <author>
<name>name</name>
<email>[email protected]</email>
</author>
<description>This is a box</description>

b. model.sdf

<?xml version="1.0" ?>
<sdf version="1.5">
<model name="Box">
<pose>0 0 0 0 0 0</pose>
<static>true</static>
<link name="link">
  <collision name="collision">
    <geometry>
      <mesh>
        <uri>model://box/meshes/mesh1.dae</uri>
        <scale>0.25 0.25 0.25</scale>
      </mesh>
    </geometry>
  </collision>
  <visual name="visual">
    <geometry>
      <mesh>
        <uri>model://box/meshes/mesh1.dae</uri>
        <scale>0.25 0.25 0.25</scale>
      </mesh>
    </geometry>
  </visual>
</link>

c. How to use the Launch File in python

spawn_entity = Node(package='gazebo_ros',
                    executable='spawn_entity.py',
                    name="spawn_sdf_entity",
                    arguments=[ '-entity','Box','-file', LaunchConfiguration('sdf_model'),
                                '-x','1.0',
                                '-y','1.0',
                                '-z', '0.0',
                                '-R','0.0',
                                '-P','0.0',
                                '-Y','0.0'
                                ], output='screen')


return LaunchDescription([
    sdf_model,
    spawn_entity,
])

I hope this will be useful for everyone!!