Search found 21 matches

by Mark97
Wed Nov 24, 2021 5:21 pm
Forum: General Bullet Physics Support and Feedback
Topic: How to change contact force between elements
Replies: 0
Views: 56

How to change contact force between elements

Hello, I'm wondering if it is possible for Bullet Physics to run a simulation, but use an alternative function for the forces between objects. For example: setting a custom stiffness of two colliding objects, without influencing interactions with other objects. Or setting a stiffness depending on ti...
by Mark97
Tue Nov 09, 2021 12:10 pm
Forum: PyBullet Support and Feedback
Topic: Setup Bullet Physics World
Replies: 0
Views: 151

Setup Bullet Physics World

I would like to setup Bullet Physics in Visual Studio (C++). Therefore, I would like to see a physics world, and load some .obj files. However, I'm stuck at a few places: the Hello World example doesn't show anything (visual), the benchmark 3000 boxes works well, but doesn't load .obj files, the Imp...
by Mark97
Mon Nov 08, 2021 8:39 am
Forum: PyBullet Support and Feedback
Topic: Concave objects do not interact?
Replies: 0
Views: 132

Concave objects do not interact?

I've added two concave objects to my simulation. However, these fall right through each other, meaning that there is no interaction between these particles at all. [PyBullet]

Can this be fixed?
by Mark97
Sun Nov 07, 2021 1:19 pm
Forum: PyBullet Support and Feedback
Topic: How to calculate the volume of an object?
Replies: 0
Views: 121

How to calculate the volume of an object?

Hello,

I'm sure PyBullet uses the volume and other properties of objects to determine the physical quantities such as intertia.

How can I acces this info? Or calculate the volume of an object?

- Mark
by Mark97
Mon Oct 25, 2021 4:42 pm
Forum: General Bullet Physics Support and Feedback
Topic: How to re-use collision shapes among rigid bodies
Replies: 2
Views: 243

Re: How to re-use collision shapes among rigid bodies

drleviathan wrote: Mon Oct 25, 2021 3:09 pm For best results move your questions to thePyBullet Support and Feedback forum.
Thanks! I have posted it there as well. Hope to get a reply :)
by Mark97
Mon Oct 25, 2021 4:41 pm
Forum: PyBullet Support and Feedback
Topic: How to re-use collision shapes among rigid bodies
Replies: 0
Views: 156

How to re-use collision shapes among rigid bodies

In the Bullet Physics Hello World example, the following warning is made: "make sure to re-use collision shapes among rigid bodies whenever possible!" However, in PyBullet this is not mentioned. I wish to speed up computation speed, as well as add more objects. In my project I have to work...
by Mark97
Sat Oct 23, 2021 10:43 am
Forum: General Bullet Physics Support and Feedback
Topic: How to re-use collision shapes among rigid bodies
Replies: 2
Views: 243

How to re-use collision shapes among rigid bodies

In the Bullet Physics Hello World example, the following warning is made: "make sure to re-use collision shapes among rigid bodies whenever possible!" However, in PyBullet this is not mentioned. I wish to speed up computation speed, as well as add more objects. In my project I have to work...
by Mark97
Thu Oct 21, 2021 5:24 pm
Forum: PyBullet Support and Feedback
Topic: add more than 1500 objects in PyBullet
Replies: 0
Views: 230

add more than 1500 objects in PyBullet

Hello,

After loading more than 1500 objects in PyBullet, they don't appear anymore on the screen.

What causes this and how can this be changed?

Kind regards,
Mark
by Mark97
Tue Oct 19, 2021 12:51 pm
Forum: PyBullet Support and Feedback
Topic: find center of mass
Replies: 0
Views: 184

find center of mass

How can one find the center of mass of an object (.obj file) in PyBullet? getDynamicsInfo() doesn't return it, nor does getCollisionShapeData(), and resetBasePositionAndOrientation() uses the link position, which is assuredly not the center of mass. applyExternalForce() also uses the link position, ...
by Mark97
Tue Oct 19, 2021 8:30 am
Forum: PyBullet Support and Feedback
Topic: add debug browser to HelloWorld.cpp
Replies: 0
Views: 176

add debug browser to HelloWorld.cpp

When I run the 'HelloWorld.cpp' file, I can only see the console.

Sorry if this is a beginners question, but how can I add the visual world?
by Mark97
Sun Oct 10, 2021 6:00 pm
Forum: PyBullet Support and Feedback
Topic: make visible only part of object
Replies: 0
Views: 341

make visible only part of object

Hello,

How can one visualize only a part of an object? Let's say that I want to 'cut' an object in two based on the x-axis or overlap with another object?
Or could we do a 2D projection of a certain surface?

Is that possible?

Thanks!
Mark
by Mark97
Mon Oct 04, 2021 9:18 am
Forum: PyBullet Support and Feedback
Topic: How to create slider in PyBullet
Replies: 0
Views: 275

How to create slider in PyBullet

How can one create a slider in PyBullet?

In other words: how to create an object with only one degree of freedom? Let's say that I want my object to freely move in the x-direction, but is restricted in the y- and z-direction. It this possible in PyBullet?
by Mark97
Sat Oct 02, 2021 5:37 pm
Forum: General Bullet Physics Support and Feedback
Topic: J impulse is wrong in all Physics Engines
Replies: 4
Views: 1842

Re: J impulse is wrong in all Physics Engines

Have you considered WORLD_FRAME, instead of LINK_FRAME?

The link follows the object, resulting in practically no displacement. The world is a static, resulting in a deformation over time.

Hope that helps.
by Mark97
Sat Oct 02, 2021 10:10 am
Forum: General Bullet Physics Support and Feedback
Topic: 30x perfomance difference between PyBullet and Bullet3
Replies: 1
Views: 503

30x perfomance difference between PyBullet and Bullet3

I've just ran the benchmark of 3000 cubes in Bullet3 (using Visual Studio), and found a total step time of about 7 ms. (4 threads) I've copied the C++ code and translated it into Python code, and ran 3000 standard cubes in PyBullet (using Anaconda Navigator, Notebook), and found a total step time of...
by Mark97
Fri Oct 01, 2021 7:37 pm
Forum: PyBullet Support and Feedback
Topic: How to build PyBullet with CMake
Replies: 0
Views: 306

How to build PyBullet with CMake

Hello, I've tried to build PyBullet (tiny differentiable simulator) using cmake. However, I got the error message that 'files might be invalid'. Also, the quickstart guide states that I should rename 'pybullet_vs2010.dll to pybullet.pyd'. However, I could not find this file. If anyone reads this and...