Search found 4221 matches

by Erwin Coumans
Tue Jun 16, 2020 5:52 pm
Forum: PyBullet Support and Feedback
Topic: mecanum wheels
Replies: 2
Views: 31677

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: 6733

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: 7580

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: 6212

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: 7
Views: 62081

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: 7599

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: 17622

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...
by Erwin Coumans
Sat Apr 25, 2020 2:27 pm
Forum: PyBullet Support and Feedback
Topic: bot gets unstable and blows away after some time
Replies: 4
Views: 10650

Re: bot gets unstable and blows away after some time

The urdf file is missing, so we cannot reproduce it.
by Erwin Coumans
Tue Apr 21, 2020 7:30 pm
Forum: PyBullet Support and Feedback
Topic: Robot description not loaded - TCP server client connection
Replies: 1
Views: 5976

Re: Robot description not loaded - TCP server client connection

There could be some issues in the implementation, as discussed here:
https://github.com/bulletphysics/bullet ... -617133707

Please check it out again soon.
by Erwin Coumans
Mon Apr 20, 2020 11:04 pm
Forum: PyBullet Support and Feedback
Topic: MUJOCO loadMJCF actuator control
Replies: 1
Views: 6026

Re: MUJOCO loadMJCF actuator control

Please share a minimal script you use to move your robot. Note that by default, all joints have joint motors with a velocity target of 0.
You may need to disable them:

Code: Select all

for j in range (p.getNumJoints(robot)):
  p.setJointMotorControl2(robot,j, p.VELOCITY_CONTROL, force=0)
by Erwin Coumans
Mon Apr 20, 2020 9:34 pm
Forum: PyBullet Support and Feedback
Topic: remove UserDebugParameters
Replies: 2
Views: 7010

Re: remove UserDebugParameters

Use removeAllUserParameters, see the PyBullet Quickstart Guide.
by Erwin Coumans
Tue Apr 07, 2020 7:44 pm
Forum: PyBullet Support and Feedback
Topic: stepSimulation() not equivalent to setRealTimeSimulation(1)
Replies: 1
Views: 6536

Re: stepSimulation() not equivalent to setRealTimeSimulation(1)

Testing here there is no difference between stepSimulation and setRealTimeSimulation, both show instable motion due to a degenerate urdf file. Those are urdf files with degenerate values. Avoid too small mass (keep it either 0 or in range 0.01 to 100 or so) avoid large rpy angles, don't use collisio...
by Erwin Coumans
Tue Mar 17, 2020 5:44 pm
Forum: General Bullet Physics Support and Feedback
Topic: Pip install 2.6.6 - issues - Windows 10
Replies: 4
Views: 10115

Re: Pip install 2.6.6 - issues - Windows 10

I had a closer look and fixed the issue(s).

Try again using pybullet-2.6.9
pip install pybullet --upgrade
by Erwin Coumans
Tue Mar 17, 2020 3:35 pm
Forum: General Bullet Physics Support and Feedback
Topic: Pip install 2.6.6 - issues - Windows 10
Replies: 4
Views: 10115

Re: Pip install 2.6.6 - issues - Windows 10

You are not using vs2019, but Visual C++ for Python\9.0.

Uninstall visual c++ for Python and try again,using the command prompt of visual studio 2019.
by Erwin Coumans
Mon Mar 16, 2020 8:35 pm
Forum: General Bullet Physics Support and Feedback
Topic: Gravity setting for accurate joint force/torque data
Replies: 1
Views: 5160

Re: Gravity setting for accurate joint force/torque data

This is expected: joint reaction forces are influenced by gravity acceleration, there is no explicit gravity compensation performed. The gravity acceleration is N/kg. Also, for more help you may want to create a small reproduction case. There are various robots available in PyBullet SDK (panda, xArm...