Enable self-collision for Panda

[FirefoxMetzger]

I don't know if this issue should live here or in the gym_ignition_models repo.

Currently, Panda doesn't seem to have self-collisions enabled. Collision with other objects works fine. See for example this video (at around 0:08 - 0:09):

https://user-images.githubusercontent.com/4402489/113131592-43b49580-91d2-11eb-863c-84bcdb292fee.mp4

Would it be possible to enable it by default, or provide an option to enable it?

[diegoferigo]

Contacts and collisions are part of what I call the bottleneck features. When enabled, simulations could slow down considerably.

For this reason, contact detection and self collisions are disabled by default (contacts [1], collisions). You can enable self collisions model-wise with the following method:

https://github.com/robotology/gym-ignition/blob/bba62416e97fe5788019e32cae66355bcb9fe70a/cpp/scenario/gazebo/include/scenario/gazebo/Model.h#L174-L183

[1] I actually realized that contacts are enabled by default. We should understand what is the impact to the real time factor, and if it makes sense to disable them by default.

[FirefoxMetzger]

In python this will need to be cast to_gazebo() first:

panda.to_gazebo().enable_self_collisions(True)

I should first read the docs more thoroughly before opening new issues 🥇 I totally forgot to check the Gazebo API and just looked at the core API. Closing...

[diegoferigo]

No worries, we can consider issues as part of a project's documentation :wink: One nice thing with SWIG (much more difficult to get with pybind11) is that the C++ doxygen documentation is copied to the Python's docstring. I admit that, as you, I rarely rely on the online documentation. Nowadays autocompletion is much faster.