Jiminy-py

Maintenance update fixing minor bugs. Some pre-compiled dependencies have been updated.

Improvements

* [core] Compute centroidal dynamics derivative systematically. (365)
* [gym/toolbox] Refactor Rllib PPO to always perform a single forward pass. (366)

Patches and bug fixes

* [core] Fix computation of external forces. (365)
* [core/python] Fix wrong output array shape for single row or single element eigen matrix.

Miscellaenous

* [core] Fix eigen stack memory alignment for support of AVX2 instructions.
* [misc] Add legacy build of jiminy wheel for python 3.8 (numpy<1.20).
* [misc] Update dependencies (eigenpy==2.6.4, hppfcl==1.7.4).
* [misc] Fix wheel manylinux seperated artefacts generation. (364)

Another minor release, focusing only on improving performance of constrained inverse dynamics implementation. A very significant speedup by a factor 5 or 10 can be expected.

Improvements

* [core] Increase efficiency of inverse dynamics in Python.

Patches and bug fixes

* [python/viewer] Fix edge case when default-initializing viewer for theoretical model.

Fix several bugs introduced in previous release.

Patches and bug fixes

* [core] Fix segfault and compilation bug on Windows.
* [python/dynamics] Fix wrong application point for spatial velocity and acceleration frames.
* [python/viewer] Fix viewer edge cases when displaying several robots at once.
* [python/viewer] Fix legend aspect ratio in Panda3d, and display it in line at bottom.
* [python/viewer] Fix clock widget for Panda3d.
* [gym/toolbox] Fix edge case in curriculum task scheduler.

This release introduces several experimental reinforcement learning features, along with a new inverse dynamics helper. A few bugs long-lasting bugs and inconsistencies in core have finally been addressed.

New features

* [python/dynamics] Add inverse dynamics helper.
* [gym/toolbox/rllib] Add policy symmetry regularization to PPO.
* [gym/toolbox/rllib] Add discrete hierarchical task space curriculum sampling.

Improvements

* [core] Expose 'Model.computeConstraint' in Python bindings.
* [core] Do not update forward kinematics (position) in 'Robot.computeConstraints'.
* [python/dynamics] Simplify helpers to take advantage of new pinocchio features.
* [gym/toolbox/rllib] Automatically connect to existing cluster if any.
* [gym/toolbox/rllib] Add helper to restore policy without trainer nor ray redis.
* [gym/toolbox/rllib] Add memory tracing for memory leaks in debug mode.

Patches and bug fixes

* [core] Fix memory leaks in Eigen->Numpy Python bindings.
* [core] Rename 'Model.hasConstraint' in 'Model.hasContraints' for consistency.
* [core] Fix motor armatures not properly propagated after setting motor options.
* [python/dynamics] Replace pinocchio methods by jiminy core overloads when appropriate.

Miscellaneous

* [python] Add some missing documentations.
* [misc] Fix python executable detection on manylinux sometimes finding pypy instead of cython.
* [misc] Updating gitignore to support use of virtual environment.

This release introduces a set of reinforcement learning tools based on [ray[rllib]](https://docs.ray.io/en/master/rllib.html). In addition, it is now easier to replay and compare trajectories in different formats (sequence of states, log files, log data, and current simulation).

New features

* [python/simulator] Replay extra logs/trajectories with current simulation.
* [gym/toolbox/rllib] Add dedicated rllib toolbox.
* [gym/toolbox/rllib] Provide [PPO CAPS](https://arxiv.org/pdf/2012.06644.pdf) implementation.

Improvements

* [python/viewer] Refactor Panda3d backend screen refresh and Qt widget to avoid edge cases.
* [gym/toolbox/rllib] Do not provide default log dir since it is error prone

Minor patch to fix viewer issues introduced in previous release.