Search found 31 matches
- Mon Jan 13, 2014 2:26 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: btSliderConstraint
- Replies: 9
- Views: 9396
btSliderConstraint
Hello everyone, I'm trying to include slider constraints into my bullet project after having successfully included 6dof, ball socket and hinge. With sliders however, I have surprisingly bad results. Basically, each object only ever seems to travel along it's X Axis. I found an old thread in this for...
- Mon Jan 13, 2014 2:19 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Building Bullet 2.81 on Windows 8 (cmake and make errors)
- Replies: 2
- Views: 5178
Re: Building Bullet 2.81 on Windows 8 (cmake and make errors
I'm not sure if I answer correctly but I answer nonetheless as I build on Windows successfully .-) About the errors concerning GLUT: Don't worry about them. Unless you actually have GLUT in your environment and plan to use it, e.g. for debug output. I get the same errors and just ignore them. Also, ...
- Thu Jan 09, 2014 2:36 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: btConeTwistConstraint with friction?
- Replies: 1
- Views: 3133
Re: btConeTwistConstraint with friction?
A semi-solution here: It appears to be possible to emulate a ball socket constraint using a generic 6dof constraint. With this, you can activate the 3 angular motors and achieve the desired effect. The constraint is quite unstable though. Gravity lets the objects slowly fall. You have to crank up it...
- Wed Jan 08, 2014 2:26 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: btConeTwistConstraint with friction?
- Replies: 1
- Views: 3133
btConeTwistConstraint with friction?
Hello, On another occasion I have simulated rotation friction on a hinge constraint by using the angular motor with target speed 0. Which works OK. Now my question is, is there a similar trick to emulate friction on a cone twist constraint as well? I tried the motor but it requires a target rotation...
- Fri Nov 29, 2013 12:22 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Constraint range
- Replies: 3
- Views: 3522
Re: Constraint range
Thanks for the clarification. I understand this is all stuff that is supposed to be handled in the simulation substep handler. So far I only extract collision information in there. Looks like there's way more to be done. I'll look into it. BTW, maybe someone can point me to a good starting point? Li...
- Fri Nov 29, 2013 9:53 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Hinge Constraint with friction
- Replies: 10
- Views: 10924
Re: Hinge Constraint with friction
Most certainly sounds like you have too few iterations and too large a time step. Try something like 500 iterations at 1/500 maximum step size (don't forget to take into account the maxSubStep, should be high enough that frame-rate drops won't mess with physics, unless of course you want the door t...
- Thu Nov 28, 2013 1:09 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Hinge Constraint with friction
- Replies: 10
- Views: 10924
Re: Hinge Constraint with friction
Well, there's limits as to what I can do here because we actually expose many of these values to the user. The system we are building here is like a physical world building blocks like things. The user can import meshes into the system and then freely set the mass of each object. The local inertia v...
- Thu Nov 28, 2013 10:33 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Hinge Constraint with friction
- Replies: 10
- Views: 10924
Re: Hinge Constraint with friction
There's one more thing that puzzles me about that hinge. It allows for an amazing amount of movement of the hinge axis. Considering a door example, if I have a dynamic object push the door open it will do so, but the actual door will wobble in it's hinge quite a bit. From visual judgement I would sa...
- Thu Nov 28, 2013 8:53 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Constraint range
- Replies: 3
- Views: 3522
Re: Constraint range
Right, I couldn't find an answer to all the questions by myself but in case anyone is interested I have a few things. There seems to be no generic way to solve this. By taking the ConstraintDemo examples and applying that to my own use case I found a way to at least make the constraint "weaker&...
- Wed Nov 27, 2013 1:08 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Hinge Constraint with friction
- Replies: 10
- Views: 10924
Re: Hinge Constraint with friction
A little update here. I have tried all sorts of iteration limits for this now an I cannot see any effect at all. So I guess it's huge motor impulse for now.
Thanks,
Moose
Thanks,
Moose
- Wed Nov 27, 2013 8:02 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Constraint range
- Replies: 3
- Views: 3522
Constraint range
Hello, I am in the final stages of a bullet based project about integrating bullet into a large commercial visualizations system. It has been challenging, interesting and also a lot of fun to see things moving in a natural like fashion. Much like the ConstraintDemo we are using 6dof generic constrai...
- Wed Nov 27, 2013 7:48 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Hinge Constraint with friction
- Replies: 10
- Views: 10924
Re: Hinge Constraint with friction
You are saying that my solution is not the preferred (as in right) way?
I have tried to set the iterations to 50 which had no effect. I'm gonna try 200 and see what it does.
About direct solvers, I don't know what that is. Would you care to elaborate please?
Thanks,
Moose
I have tried to set the iterations to 50 which had no effect. I'm gonna try 200 and see what it does.
About direct solvers, I don't know what that is. Would you care to elaborate please?
Thanks,
Moose
- Tue Nov 26, 2013 1:12 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Small cmake change request
- Replies: 3
- Views: 3463
Re: Small cmake change request
I just stumbled over the same issue, replacing 2.81 by 2.82 here.
You should use <bullet_project_name>_SOURCE_DIR rather than CMAKE_SOURCE_DIR, that's for sure.
You should use <bullet_project_name>_SOURCE_DIR rather than CMAKE_SOURCE_DIR, that's for sure.
- Tue Nov 26, 2013 12:56 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Hinge Constraint with friction
- Replies: 10
- Views: 10924
Re: Hinge Constraint with friction
Flix,
thanks for your response. As it so happens, you were right. I sort of figured that out trying wild combinations at the same time. If I set the max impulse very high, it has the desired effect. Like that:
hinge_constraint->enableAngularMotor(true, 0 , 100000.0);
Thanks for the help.
Moose
thanks for your response. As it so happens, you were right. I sort of figured that out trying wild combinations at the same time. If I set the max impulse very high, it has the desired effect. Like that:
hinge_constraint->enableAngularMotor(true, 0 , 100000.0);
Thanks for the help.
Moose
- Tue Nov 26, 2013 10:28 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Hinge Constraint with friction
- Replies: 10
- Views: 10924
Hinge Constraint with friction
Hello, I need a hinge constraint with friction to simulate a certain resistance when a user interacts with an object. Now in this forum I read I can use an angular motor like this: hinge_constraint->enableAngularMotor(true, 0.0, 0.02); I understand this is to create a motor with a target velocity of...