Pinocchio: [documentation] Tutorials not working

[mehdi-benallegue]

Hi all,

I tried to install and experience Pinocchio as a simple user and I can report on some difficulties I met during the process.

In the beginning, I was on the tutorial of the home page of the project http://projects.laas.fr/gepetto/doc/stack-of-tasks/pinocchio/master/index.html which does generally not work by following the displayed steps (I can provide details if needed) then @jcarpent sent me to this more recent tutorial http://projects.laas.fr/gepetto/index.php/Teach/Supaero2018 which maybe could replace the official one.

I'm on Ubuntu 16.04 and here are my remarks
-the installation procedure misses the essential package robotpkg-py27-pinocchio (and hence its dependency robotpkg-py27-eigenpy)
-If we try to install the UR5 gripper description through robotpkg-ur5-description, the URDF is installed by default in /opt/openrobots/share/ur5_description, and the model cannot be loaded unless one renames the directory into ur_description instead. However, the zip provided in the tutorial works well.
-Loading the urdf model from the zip file went well, but the display was buggy. Here is a screen capture.

https://drive.google.com/open?id=0B5Qp1o1Z6OarOHlDTmJrZ1Q2M2lsTjRteHJWREVOWVZpWXh3

-I stopped there. All these steps were performed on a raw virtual machine that you can download and load in VirtualBox from here
https://drive.google.com/file/d/1gRseDTwK5Nvhydla20Yq6yXLX6z7HAF4/view?usp=sharing
the user password is carpentier

For my personal use I do _not_ need the display, and I am actually using it successfully for some tests in C++. So there is no emergency for me, but I wanted to know if I did anything wrong.

[gabrielebndn]

Hi! As for the loading, it is not a bug. initDisplay just loads the meshes and puts them in the gui, but does not place them. If after initDisplay you do robot.display(<whathever>), it should be correct. Maybe it can be a good idea to have this first call done automatically so to show a correct robot

[gabrielebndn]

Why do you say the installation procedure misses robotpkg-py27-pinocchio ?
It seems to be correctly indicated in https://stack-of-tasks.github.io/pinocchio/download.html. The installation line is provided as

sudo apt install robotpkg-py27-pinocchio

[gabrielebndn]

Ok, you were referring to the tutorial at http://projects.laas.fr/gepetto/index.php/Teach/Supaero2018. Yes, it misses robotpkg-py27-pinocchio, thanks for reporting it.

[mehdi-benallegue]

OK for the display, it means that the error messages on the gepetto-gui terminal must be ignored. I should have gone further. I am actually having other troubles with another robot (Sawyer), but this is not relevant to this issue.

With regard to the official tutorial:
-The installation procedure here http://projects.laas.fr/gepetto/doc/stack-of-tasks/pinocchio/master/md_doc_d-labs_1-directgeom.html is not enough since it misses the environment variables update.
-There is a typo in the line 5 of http://projects.laas.fr/gepetto/doc/stack-of-tasks/pinocchio/master/md_doc_c-tutorials_direct-geometry.html
-And I still think the "supaero" lessons' tutorial should be the default instead.

Thank you for your replies.

[gabrielebndn]

We are in the process of re-making the whole documentation.
You can find more up-to-date tutorials in the topic/doc-v2 branch, which has just been updated to Pinocchio 2.0

[gabrielebndn]

Yes, gepetto-gui produces a lot of noisy warnings which can usually be ignored, but that's a matter with gepetto-gui.

[gabrielebndn]

As for the URDF, I do not understand why you changed the name of the ur5 directory, instead of simply changing, in the tutorial

urdf = pkg + '/ur_description/urdf/ur5_gripper.urdf'

to

urdf = pkg + '/ur5_description/urdf/ur5_gripper.urdf'

I think the robotpkg naming scheme is the correct one. Both the ZIP and the tutorial should be modified to reflect it.

[gabrielebndn]

Thanks for reporting these problems! I think we can close the issue

[mehdi-benallegue]

It seems not that simple!
https://drive.google.com/open?id=12x9XyFymDuznMF8QGsshChX36QgXHrDs

[jmirabel]

Install ros-kinetic-ur-description to get it work.

Having a package ur5_description in robotpkg is a bad idea. We should only rely on ur_description. However, as of now, it is not possible to generate the URDF string from xacro file and pass this to Pinocchio. It should not be hard to achieve as Pinocchio can parse URDF passed as string.

[gabrielebndn]

I am not having this problem.
I think I understood why.
From what you posted, it seems robotpkg-ur5-description contains a mistake, but mine doesn't.
I guess that's because I have robotpkg/wip in my apt list. The version there is correct and overrides the normal one. I'll check

[gabrielebndn]

@jmirabel his example is working fine for me. I explain above a possible cause, but I'll check

[mehdi-benallegue]

@jmirabel that is what I did. But it means ROS is necessary just to get URDF description. I don't know if the zip solution is good either.

@gabrielebndn you may want to try on the virtual machine

[gabrielebndn]

@mehdi-benallegue I will

[mehdi-benallegue]

P.S. I mean I installed the ros package on my desktop PC but I noticed this fix (renaming) on the virtual machine.

[gabrielebndn]

I confirm that the error is originating from the robotpkg-ur5-description folder being broken, but repaired in robotpkg/wip. The problem is solved by

> sudo tee /etc/apt/sources.list.d/robotpkg.list <<EOF
deb [arch=amd64] http://robotpkg.openrobots.org/wip/packages/debian/pub $codename robotpkg
deb [arch=amd64] http://robotpkg.openrobots.org/packages/debian/pub $codename robotpkg
EOF
> sudo apt-get update
> sudo apt-get install --only-upgrade robotpkg-ur5-description

I will push for the repo to be updated. Thanks a lot for your help!
I think all doubts are solved now, we can close the issue

[nim65s]

Yes, I fixed it in robotpkg-wip, but this is not a satisfactory solution… I still have to work on it.