Real-Time Physics Simulation Forum

Re: Not connected to physics server when trying to run environment

2022-03-15T02:44:50+00:00

Please check out those examples, they show how to implement multiprocessing with PyBullet, you need to be careful:

https://github.com/bulletphysics/bullet ... bots/panda

Statistics: Posted by Erwin Coumans — Tue Mar 15, 2022 2:44 am

Re: Not connected to physics server when trying to run environment

2022-03-14T17:52:02+00:00

Forgot to mention, the other script from the same github repo work fine.
E.g.
spot_ars_eval.py
env_tester.py

The problem seems to be when spot_ars.py is using multiprocessing workers for the training.

Statistics: Posted by dogbuilder23 — Mon Mar 14, 2022 5:52 pm

Re: Not connected to physics server when trying to run environment

2022-03-14T17:49:37+00:00

I'm getting this error when trying to run
https://github.com/OpenQuadruped/spot_m ... pot_ars.py

regardless of the flag values I choose.

I'm running
Python 3.8.9
pybullet build time: Dec 27 2021 18:13:03
MacOS 12.0.1, on a MacBook Pro (16-inch, 2021) M1 Max.

I'm a PyBullet noob. Any advice would be appreciated.

Statistics: Posted by dogbuilder23 — Mon Mar 14, 2022 5:49 pm

Re: Not connected to physics server when trying to run environment

2020-06-06T06:35:20+00:00

Comment this code and replace them with a pass, everything will be fine.

The pybullet connection for those envs are created in the env.reset() method.
You are making a call to global pybullet.getNumBodies before calling the reset, which is wrong.
Also, it is unsafe to use global pybullet together with a bullet_client.

Code:

env = gym.make("AntBulletEnv-v0")print(p.getNumBodies())print(env.reset())

Change the code to this:

Code:

env = gym.make("AntBulletEnv-v0")print(env.reset())print(p.getNumBodies())

The delayed __del__ is not an issue at all, since the env.close() calls the disconnect.

Statistics: Posted by Erwin Coumans — Sat Jun 06, 2020 6:35 am

Re: Not connected to physics server when trying to run environment

2019-11-14T05:30:59+00:00

Sorry, this just can fix my issue.

Statistics: Posted by caffett — Thu Nov 14, 2019 5:30 am

Re: Not connected to physics server when trying to run environment

2019-11-14T05:24:13+00:00

https://github.com/bulletphysics/bullet ... y#L18-#L22

Comment this code and replace them with a pass, everything will be fine.

The python garbage collection mechanism will not delete the variable immediately. Thus, there will be a delay to call the __del__. When the __del__ is called, it will close the current connection, however, due to the delay, the connection might not be the connection we want to close at begin.

Statistics: Posted by caffett — Thu Nov 14, 2019 5:24 am

Re: Not connected to physics server when trying to run environment

2019-11-13T21:40:55+00:00

Similar bug.

Code:

# -*- coding: utf-8 -*-import pybullet as pimport pybullet_envsimport gymdef show_bug():env = gym.make("AntBulletEnv-v0")print(env.reset())print(p.getNumBodies())env.step(env.action_space.sample())env.close()env = gym.make("AntBulletEnv-v0")print(env.reset())print(p.getNumBodies())env.step(env.action_space.sample())env.close()env = gym.make("AntBulletEnv-v0")print(p.getNumBodies())print(env.reset())env.step(env.action_space.sample())env.close()print("end!")if __name__ == "__main__":show_bug()

Statistics: Posted by caffett — Wed Nov 13, 2019 9:40 pm

Not connected to physics server when trying to run environment

2019-07-22T20:52:44+00:00

Hi,

I'm trying to use PyBullet for reinforcement learning and can't get started with a simple example. The code below fails with the following error:

Traceback (most recent call last):
File "test.py", line 10, in
observation, reward, done, info = env.step(action)
File "/home/john/anaconda3/lib/python3.6/site-packages/gym/wrappers/time_limit.py", line 15, in step
observation, reward, done, info = self.env.step(action)
File "/home/john/anaconda3/lib/python3.6/site-packages/pybullet_envs/gym_pendulum_envs.py", line 31, in step
self.robot.apply_action(a)
File "/home/john/anaconda3/lib/python3.6/site-packages/pybullet_envs/robot_pendula.py", line 25, in apply_action
self.slider.set_motor_torque(100 * float(np.clip(a[0], -1, +1)))
File "/home/john/anaconda3/lib/python3.6/site-packages/pybullet_envs/robot_bases.py", line 381, in set_motor_torque
self.set_torque(torque)
File "/home/john/anaconda3/lib/python3.6/site-packages/pybullet_envs/robot_bases.py", line 387, in set_torque
force=torque)#, positionGain=0.1, velocityGain=0.1)
pybullet.error: Not connected to physics server.

Code:

import gymimport pybullet, pybullet_envsenv = gym.make('InvertedPendulumBulletEnv-v0')observation = env.reset()for _ in range(1000):    env.render()    action = env.action_space.sample()    observation, reward, done, info = env.step(action)    if done:        observation = env.reset()    env.close()

I'm using Python 3.6.7 and PyBullet 2.5.2 installed using pip on Ubuntu. Any ideas?

Statistics: Posted by jboyml — Mon Jul 22, 2019 8:52 pm