See https://github.com/erwincoumans/pybullet_robots ANYmal.py for an example.
PyBullet: Expose p.setPhysicsEngineParameter(solverResidualThreshold=1e-2) (b3PhysicsParamSetSolverResidualThreshold), increases solver performance a lot
PyBullet: Expose p.setPhysicsEngineParameter(contactSlop) Set it to zero, to avoid issues with restitution.
PyBullet: Expose isNumpyEnabled, return True is PyBullet was compiled with NUMPY support for 'getCameraImage'.
PyBullet: Expose p.ChangeDynamics(objectUid, linkIndex, contactProcessingThreshold), to avoid issues of speculative/predictive contacts with restitution.
See also http://twvideo01.ubm-us.net/o1/vault/gdc2012/slides/Programming%20Track/Vincent_ROBERT_Track_ADifferentApproach.pdf
use p.JOINT_FEEDBACK_IN_JOINT_FRAME if you want the joint feedback expressed in joint frame (instead of link inertial frame)
use p.JOINT_FEEDBACK_IN_WORLD_SPACE if you want the joint feedback in world space coordinates, instead of local link/joint coordinates.
Example: p.setPhysicsEngineParameter(jointFeedbackMode=p.JOINT_FEEDBACK_IN_WORLD_SPACE+p.JOINT_FEEDBACK_IN_JOINT_FRAME)
See also data\toys\concave_box.urdf and data\toys\concave_box.cdf
data\toys\concave_box.cdf was generated from concave_box.obj using
//GenerateSDF.exe -r "32 32 32" -d "-1.6 -1.6 -.6 1.6 1.6 .6" concave_box.obj
//SDF is based on code from DiscreGrid, https://github.com/InteractiveComputerGraphics/Discregrid
add them to pybullet_envs through __init__.py
id='MinitaurReactiveEnv-v0',
id='MinitaurTrottingEnv-v0',
id='MinitaurBallGymEnv-v0',
id='MinitaurStandGymEnv-v0',
id='MinitaurAlternatingLegsEnv-v0',
id='MinitaurFourLegStandEnv-v0',
disable reflection of minitaur_four_leg_stand_env, since the floor changes orientation (reflection is a fixed plane with [0,0,1] normal)
from pybullet_envs.minitaur.envs.minitaur_alternating_legs_env import MinitaurAlternatingLegsEnv
from pybullet_envs.minitaur.envs.minitaur_ball_gym_env import MinitaurBallGymEnv
from pybullet_envs.minitaur.envs.minitaur_randomize_terrain_gym_env import MinitaurRandomizeTerrainGymEnv
from pybullet_envs.minitaur.envs.minitaur_reactive_env import MinitaurReactiveEnv
from pybullet_envs.minitaur.envs.minitaur_stand_gym_env import MinitaurStandGymEnv
from pybullet_envs.minitaur.envs.minitaur_trotting_env import MinitaurTrottingEnv
from pybullet_envs.minitaur.envs.minitaur_four_leg_stand_env import MinitaurFourLegStandEnv
