Relative path of meshes in SDF export not working

[dettmann]

Describe the bug
When you export a sdf model you cannot export relative mesh paths.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'Phobos's Export'
2. Check 'sdf' and 'dae' as export options and select 'relative' file path for meshes.
3. Clkick 'Export Model'
4. Hava a look at the exported sdf file.

Expected behavior
In visual section of a link, I would expect some relative link to the mesh like:

<geometry>
    <mesh>
          <uri>../meshes/dae/<mesh_name>.dae</uri>
          <scale>1.0 1.0 1.0</scale>
     </mesh>
</geometry>

. Instead a model path is referenced like:

<geometry>
    <mesh>
          <uri>model://<model_name>/meshes/<mesh_name>.dae</uri>
          <scale>1.0 1.0 1.0</scale>
     </mesh>
</geometry>

, which I would expect when you select "ros_package" as file path option.

Desktop

• OS: Ubuntu 22.04
• Blender 3.01
• Phobos git has id: 8731dcf

[Henning Wiedemann]

Hi Alex,
please try the branch pre_v2.0.0. I'd appreciate every tester there ;)

[dettmann]

Hi Henning,

thanks for the quick reply. I just tested and had following issues:

1. the update process was maybe not clear to me, but installing the new phobos.zip add-on in the blender preferences lead to the fact that the phobos gui elements were vanished. I could only solve it by re-installing blender again.

2. After a fresh blender install and installing the phobos add-on, during activation the following error occured:

   File "/home/dettmann/.config/blender/3.0/scripts/addons/phobos/blender/phobosgui.py", line 77, in PhobosPrefs default=os.getlogin(),
   FileNotFoundError: [Errno 2] No such file or directory

   Maybe this is related to my WSL usage? However, I solved this by manually setting my user name, for now.

3. Then, the installation worked, but following error was printed (and ignored by me):

   Python: Traceback (most recent call last):
   File "/home/dettmann/.config/blender/3.0/scripts/addons/phobos/blender/phobosgui.py", line 789, in draw
   errors = validation.validateObjectNames(obj)
   AttributeError: module 'phobos.blender.utils.validation' has no attribute 'validateObjectNames'. Did you mean: 'validateObjectPose'?

4. The export of an existing model was working after redefining the link as motor. But the export misses the xml and sdf version, the first only being important for syntax highlighting whereas the second missing prevents gazebo from parsing the file. Adding manually something like this works:

5. The export option "Force almost zero to zero" does not work.

6. The loaded model is black in gazebo, i.e. the mesh colors are not transorted. However, this might be another issue since it was completely grey before (which was also not correct).

I hope my test report helps you to improve this wonderful software ;)

[Henning Wiedemann]

Hi Alex,
thanks for the feedback.

1. I don't know how you did it, but updating should be safe and system independent as follows:
   1. Remove the old add-on
   2. Close blender
   3. In case of phobos 2.0.0 install the requirements by running ${BLENDER_EXECUTABLE} -b --python install_requirements.py
   4. Start blender again
   5. Install the new phobos.zip
2. I haven't yet tested blender under WSL. But can't you use directly in Windows instead of WSL?
3. Should be solved lately.
4. Sounds weird. For existing models I have not yet prepared an update script for models in blend files. Loading the old smurf to blender should work, in case you have not stored any additional data in the blend file. Regarding the export I guess this might be a follow up of the old version blend file. I'll let you know when there's the update script.
5. Should be solved. ;)
6. I guess this relates to the dae Meshes. They are a bit annoying as they have their own material that overrides the urdf material... I'm still working on a solution for this.

Best,
Henning

[dettmann]

Hi Henning,

thanks for the quick fixes :) The update process as described above worked as well.

Best, Alex