Search found 4221 matches
- Sat Aug 24, 2019 12:21 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Pybullet Deterministic Simulation
- Replies: 2
- Views: 7416
Re: Pybullet Deterministic Simulation
PyBullet is fully 100% deterministic after calling resetSimulation and adding the objects in the same order. Many of our reinforcement learning environments rely on this. In fact, there are unit tests that show that PyBullet is also fully deterministic after a save/restoreState call, not just resetS...
- Wed Aug 07, 2019 8:11 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Bullet on colab
- Replies: 2
- Views: 6881
Re: Bullet on colab
OpenGL isn't available from within a colab/browser. You can still use getCameraImage to render images, using the software renderer. (TinyRenderer)
- Tue Jun 25, 2019 8:43 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Tossing Bot simulation environment
- Replies: 1
- Views: 5297
Re: Tossing Bot simulation environment
I don't think this environment is made open source.
- Thu May 02, 2019 4:28 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Stabilize "dantzing" on nearby contacts using custom combiner callback.
- Replies: 4
- Views: 12613
Re: Stabilize "dantzing" on nearby contacts using custom combiner callback.
For robotics purposes we developed the btMultiBody and PyBullet and its C and C++ robotics API . You may want to try btMultiBody instead of btRigidBody, and PyBullet/C++ robotics API has most of the settings more suitable for such tasks. So I suggest to create a quick prototype in PyBullet and then ...
- Fri Apr 12, 2019 1:38 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Load File from URDF and convert to Rigidbody (RobotSimulator)
- Replies: 2
- Views: 8865
Re: Load File from URDF and convert to Rigidbody (RobotSimulator)
There is a better way to limit motion for reduced coordinate (btMultiBody): instead of using a free base, use a fixed base and add additional degrees of freedom to enable motion along the axis you want. See the biped2d example how this is done: https://github.com/bulletphysics/bullet3/blob/master/ex...
- Fri Apr 12, 2019 1:33 am
- Forum: PyBullet Support and Feedback
- Topic: Manipulating Kuka-robot joint using Torque-control
- Replies: 2
- Views: 13683
Re: Manipulating Kuka-robot joint using Torque-control
You need to first unlock/disable the default velocity/position motor: pybullet.setJointMotorControl2(objUid, linkIndex, p.VELOCITY_CONTROL, force=0) Otherwise, your force/torque has to exceed the default motor. Instead of using 0, you can also use a very small force limit, to mimic joint friction. I...
- Tue Apr 09, 2019 6:13 am
- Forum: General Bullet Physics Support and Feedback
- Topic: why call the computeAccelerationsArticulatedBodyAlgorithmMultiDoft twice?
- Replies: 2
- Views: 5908
Re: why call the computeAccelerationsArticulatedBodyAlgorithmMultiDoft twice?
Good point, the second pass is used for joint feedback (using results from the constraint solver).
We can add a check for 'body->internalNeedsJointFeedback()' around line 720 of btMultiBodyDynamicsWorld. Mind sending a patch to github?
We can add a check for 'body->internalNeedsJointFeedback()' around line 720 of btMultiBodyDynamicsWorld. Mind sending a patch to github?
- Thu Mar 21, 2019 9:36 pm
- Forum: PyBullet Support and Feedback
- Topic: Spherical Joints
- Replies: 10
- Views: 26708
Re: Spherical Joints
Actually my implementation of DeepMimic in PyBullet is working fine. We ignore the inertia data from URDF and recompute it based on collision shapes, and that data is identical from the original DM. We can re-use the original policy with stable PD control, so all is fine. You can use 1200Hz, but by ...
- Wed Mar 20, 2019 1:56 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: 2 Dynamic objects Oscillating
- Replies: 2
- Views: 6206
Re: 2 Dynamic objects Oscillating
You should always use the very latest Bullet version from github. Aside from that, you can 1) use btBoxShape 2) use a smaller time step or increase the number of substeps 3) use more solver iterations or use a direct solver (Dantzig) 4) avoid large mass ratio If you have issues, always create a smal...
- Fri Mar 15, 2019 4:18 am
- Forum: General Bullet Physics Support and Feedback
- Topic: MultiBody and RigidBody: architectural design of an application
- Replies: 4
- Views: 9317
Re: MultiBody and RigidBody: architectural design of an application
You can attach btMultiBody and btMultiBody/btRigidBody using constraints. I would recommend checking out PyBullet to create a prototype, it uses btMultiBody by default under the hood. When using 'useMaximalCoordinates=True' it uses btRigidBody.
- Sun Mar 10, 2019 12:19 am
- Forum: PyBullet Support and Feedback
- Topic: Spherical Joints
- Replies: 10
- Views: 26708
Re: Spherical Joints
You didn't disable the motors, as is done in humanoidMotioncapture.py, add this block: #disable motors for j in range (p.getNumJoints(model)): ji = p.getJointInfo(model,j) targetPosition=[0] jointType = ji[2] if (jointType == p.JOINT_SPHERICAL): targetPosition=[0,0,0,1] p.setJointMotorControlMultiDo...
- Sat Mar 09, 2019 1:26 am
- Forum: PyBullet Support and Feedback
- Topic: Spherical Joints
- Replies: 10
- Views: 26708
Re: Spherical Joints
The humanoidMotionCapture.py example shows how to use spherical drives. Also one of the humanoids in that example use resetJointStateMultiDof to set its state. Both modes works just fine with me. Please check it.
- Sat Mar 09, 2019 1:24 am
- Forum: PyBullet Support and Feedback
- Topic: Position control for robot base?
- Replies: 13
- Views: 34713
Re: Position control for robot base?
You can attach the base to the (fixed) world frame with a couple of degrees of freedom. Then you can apply setJointMotorContro2 in POSITION_CONTROL mode, or VELOCITY_CONTROL mode to those degrees of freedom to move the base.
- Sat Mar 09, 2019 1:21 am
- Forum: PyBullet Support and Feedback
- Topic: Simulating indirect drives
- Replies: 1
- Views: 6078
Re: Simulating indirect drives
We currently don't have an API to exceed the maximum RPM of 100, but we probably should add it.
There is an old issue here, I should implement it:
https://github.com/bulletphysics/bullet3/issues/1890
There is an old issue here, I should implement it:
https://github.com/bulletphysics/bullet3/issues/1890
- Sat Mar 09, 2019 1:18 am
- Forum: PyBullet Support and Feedback
- Topic: Moving from Bullet 2 to Pybullet
- Replies: 6
- Views: 16621
Re: Moving from Bullet 2 to Pybullet
>> The visualization will be done using a 3D engine. >> - Motion states. Is your 3d engine also Python or C++? How do you want to synchronize the graphics transforms? Through C++ / shared memory, or using Python? If it happens in Python, we could add a method that receives only the updated objects. ...