Search found 8 matches

by daye
Thu Oct 31, 2019 6:56 am
Forum: General Bullet Physics Support and Feedback
Topic: Complementarity problem and friction approximation in Bullet
Replies: 0
Views: 515

Complementarity problem and friction approximation in Bullet

I am confused about what kind of complementarity problem that Bullet solved. I have read some thesis and posts in the forum. Someone stated that Bullet solved the MLCP for the contact, due to the frcition cone was simplified. But others said Bullet can solve the NCP directly with the PGS solver. I d...
by daye
Thu Aug 15, 2019 9:38 am
Forum: General Bullet Physics Support and Feedback
Topic: Problems occurred when the validation of the Bullet's accuracy with a bouncing ball test
Replies: 5
Views: 842

Re: Problems occurred when the validation of the Bullet's accuracy with a bouncing ball test

I have tested your suggestion. But the simulated result is even worse. When the ball contacted with the floor, it rested on the floor. :shock: When I set the time step as world->stepSimuation(1/60.0, 1, 1/60.0) , the simulation gave the results as the figure in my first post. There is another questi...
by daye
Tue Aug 13, 2019 6:30 am
Forum: General Bullet Physics Support and Feedback
Topic: Problems occurred when the validation of the Bullet's accuracy with a bouncing ball test
Replies: 5
Views: 842

Re: Problems occurred when the validation of the Bullet's accuracy with a bouncing ball test

Thank you for your reply! The simulation used the fixed substep and its duration is 1/600. The max substeps is 10. I am using double precision and the version is bullet3-2.87. In the simulation, the floor was set as btStaticPlaneShape. Here is part of my code: btTransform t; t.setIdentity(); t.setOr...
by daye
Mon Aug 12, 2019 6:13 am
Forum: General Bullet Physics Support and Feedback
Topic: Problems occurred when the validation of the Bullet's accuracy with a bouncing ball test
Replies: 5
Views: 842

Problems occurred when the validation of the Bullet's accuracy with a bouncing ball test

Hello all, I want to validate the accuracy of Bullet. I simulated a bouncing ball contacting with a static plane only with the gravity. The ball's trajectory was recorded and compared with the analytic solution. But large errors occurred after a few collisions. I don't know what caused the discrepan...
by daye
Sun Jan 06, 2019 1:31 am
Forum: General Bullet Physics Support and Feedback
Topic: Is there SAT algorithm in Bullet Physics Engine
Replies: 2
Views: 683

Is there SAT algorithm in Bullet Physics Engine

Hi everyone,

I want to change the Collision Detection algorithm to SAT algorithm. I only found GJK algorithm in Bullet. Is there SAT algorithm in Bullet Physics Engine which I can call it directly? Or I have to achieve that by myself?

Thank you in advance!
Daye
by daye
Fri Jul 20, 2018 12:10 am
Forum: General Bullet Physics Support and Feedback
Topic: Is there a lower limit for velocity in Bullet?
Replies: 4
Views: 1148

Re: Is there a lower limit for velocity in Bullet?

Thank you very much! It really helps me! :lol: :lol: :lol:
by daye
Thu Jul 19, 2018 2:16 pm
Forum: General Bullet Physics Support and Feedback
Topic: Is there a lower limit for velocity in Bullet?
Replies: 4
Views: 1148

Is there a lower limit for velocity in Bullet?

Hi all, I set the body in a constant velocity, with setLinearVelocity before stepSimulation. When the velocity is higher than 1 mps, it looks well. But when I set the velocity below 1 mps, such as 0.1 mps, the body stops unbelievably after a few time steps. I'm very confused about it. Is there a low...
by daye
Wed Jul 11, 2018 2:44 am
Forum: General Bullet Physics Support and Feedback
Topic: How to get the friction force in Bullet?
Replies: 0
Views: 713

How to get the friction force in Bullet?

I'm the beginner of Bullet. In my work, I want to get the friction force between the bodies' interaction. I noticed that m_appliedImpulseLateral1 and m_appliedImpulseLateral2 in btManifoldPoint Class maybe the friction impulse during the contact procress. So I calculated the friction force as follow...