Search found 4214 matches

by Erwin Coumans
Wed Jul 08, 2020 5:02 pm
Forum: PyBullet Support and Feedback
Topic: HopperMuJoCoEnv
Replies: 1
Views: 60

Re: HopperMuJoCoEnv

PyBullet ships with HopperBulletEnv-v0, and other environments as listed here:

https://github.com/bulletphysics/bullet ... _init__.py

This forum is for PyBullet, if you want MuJoCo or Benelot's environments, try visiting another forum.
by Erwin Coumans
Wed Jul 08, 2020 12:05 am
Forum: PyBullet Support and Feedback
Topic: setJointMotorControl2 won't assign correct force value to certain joints
Replies: 5
Views: 274

Re: setJointMotorControl2 won't assign correct force value to certain joints

Don't enable 'realtime' simulation, but stepSimulation instead, when applying forces like this. Also, best to keep using a small time step (1./240. is default), not 1 second. Watch the various examples/gym environments, for example https://github.com/bulletphysics/bullet3/tree/master/examples/pybull...
by Erwin Coumans
Mon Jun 29, 2020 11:08 pm
Forum: PyBullet Support and Feedback
Topic: error: Not connected to physics server
Replies: 2
Views: 168

Re: error: Not connected to physics server

We don't support those envs. Please try using the envs included with pybullet_envs (after pip install pybullet --upgrade --user) HalfCheetahBulletEnv-v0 etc. Here is a list: https://github.com/pat-coady/trpo HumanoidDeepMimicBulletEnv-v1 CartPoleBulletEnv-v1 MinitaurBulletEnv-v0 MinitaurBulletDuckEn...
by Erwin Coumans
Fri Jun 19, 2020 4:09 pm
Forum: PyBullet Support and Feedback
Topic: [SOLVED in pybullet 2.8.2] Simple two-link URDF applyExternalForce unexpected response
Replies: 4
Views: 473

Re: Simple two-link URDF applyExternalForce unexpected response

Ah, I disabled the velocity/position motors by setting the force to zero. You can certainly leave the motors enabled, with a force of your choice to model joint friction or other effects such as springyness. I was assuming metric units (meter, seconds etc). If you are using different units, you need...
by Erwin Coumans
Fri Jun 19, 2020 3:48 am
Forum: PyBullet Support and Feedback
Topic: [SOLVED in pybullet 2.8.2] Simple two-link URDF applyExternalForce unexpected response
Replies: 4
Views: 473

Re: Simple two-link URDF applyExternalForce unexpected response

Thanks Avik, I had a look and found a few issues. One of them is in the applyExternalForce imlpementation, I fixed this now. https://github.com/bulletphysics/bullet3/pull/2870/commits/ebef331bbffb4631259648f5858a3a396dd3718a (it was a copy/paste bug, we never used applyExternalForce, since we always...
by Erwin Coumans
Tue Jun 16, 2020 5:54 pm
Forum: PyBullet Support and Feedback
Topic: JointMotor for urdf robot franka_panda
Replies: 1
Views: 423

Re: JointMotor for urdf robot franka_panda

It appears as if you are driving a strong motor against a joint limit, this won't work properly so try to avoid doing that.
by Erwin Coumans
Tue Jun 16, 2020 5:52 pm
Forum: PyBullet Support and Feedback
Topic: mecanum wheels
Replies: 1
Views: 463

Re: mecanum wheels

It is a challenging simulation problem. Make sure to 'unlock' the joint motors first, as usual.
(for each joint, setJointMotorControl2(obUid, linkIndex, p.VELOCITY_CONTROL, force=0 or close to 0).
I haven't created such robot yet, it may require a lot of effort to set this up properly.
by Erwin Coumans
Tue Jun 16, 2020 5:50 pm
Forum: PyBullet Support and Feedback
Topic: kuka reverse kinematic issue
Replies: 1
Views: 322

Re: kuka reverse kinematic issue

There are some inverse kinematics examples with Kuka, see https://github.com/bulletphysics/bullet ... ematics.py
by Erwin Coumans
Tue Jun 16, 2020 5:49 pm
Forum: PyBullet Support and Feedback
Topic: Setting Hard Constraints?
Replies: 2
Views: 405

Re: Setting Hard Constraints?

Increasing the number of solver iterations, or using a smaller time step, or increase the number of substeps. You can also improve convergence by making the masses more similar, if possible (PGS solver converges slower when large mass differences are present, such as 100 kg and 0.1 kg etc) Another o...
by Erwin Coumans
Tue Jun 16, 2020 5:48 pm
Forum: PyBullet Support and Feedback
Topic: Issue with loading a URDF file
Replies: 1
Views: 164

Re: Issue with loading a URDF file

I would recommend looking at all the various URDF files that come with PyBullet and compare with yours.

https://github.com/bulletphysics/bullet ... aster/data

https://github.com/bulletphysics/bullet ... ullet_data
by Erwin Coumans
Sat Jun 06, 2020 6:35 am
Forum: PyBullet Support and Feedback
Topic: Not connected to physics server when trying to run environment
Replies: 4
Views: 2569

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

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 w...
by Erwin Coumans
Sat Jun 06, 2020 6:03 am
Forum: PyBullet Support and Feedback
Topic: Rewards function
Replies: 3
Views: 454

Re: Rewards function

I am using PyBullet 2.5.9 and Python 3.6.9 That is a very old pybullet version, can you update to the latest and check again? pip3 install pybullet --upgrade --user >> delay with env.close() as reported here No, that is not the issue and not a bug. The Gym env creates a connection during 'reset', n...
by Erwin Coumans
Wed Jun 03, 2020 10:50 pm
Forum: General Bullet Physics Support and Feedback
Topic: Combining two Rigid Bodies?
Replies: 10
Views: 772

Re: Combining two Rigid Bodies?

btCompoundShape::calculatePrincipalAxisTransform can compute the new masses and offsets: https://pybullet.org/Bullet/BulletFull/btCompoundShape_8cpp_source.html#l00216 Another option is using btMultiBody and fixed joints. In PyBullet there is an example 'combine_urdf' that can combine two bodies. Al...