Real-Time Physics Simulation Forum

Great to hear that ! And hope you would enjoy linux as well.

Cheers !

Hi I'm new to bullet physics. I want to build a model of a robot (a salamander) to simulate how fast it can cawl. The input I have is the angles and angular speed of joints on the robot output from MATLAB. I'm not sure if I can build a powered robot system in bullet physics since all the demos are ...

I think you may want to look into CFM/ERP, as is explained by Yann in the following post:

http://bulletphysics.org/Bullet/phpBB3/ ... f=9&t=6792

The softness of the constraint is also possible for your problem.

Hi! I'm new here. I want to use bullet in my project and I want to compile it with MinGW. But when i use cmake, it shows an error that it can't find GLUT. how can i fix it? I want to use demos to learn bullet, I think Glut is needed for compiling demos. Thank you. I have moved to linux for sometime...

I think if you still want to try Generic Constraint, you have to set up like this: pGen6DOF->setLinearLowerLimit(btVector3(-1000., -1000., 0.)); pGen6DOF->setLinearUpperLimit(btVector3(1000., 1000., 0.)); The code means your constraints are limited into a large flat bounding box, which can be viewed...

The pictures looks awesome, how long does it take you to do the modelling ?

btDynamicsWorld::stepSimulation( btScalar timeStep, int maxSubSteps=1, btScalar fixedTimeStep=btScalar(1.)/btScalar(60.)); If you pass a very large timeStep as the first parameter [say, five times the size of the fixed internal time step], then you must increase the number of maxSubSteps to compens...

Hi, I have bullet correctly initialized and have 200 sphere who collide, all works fine but when i want apply force to a rigid body he doesn't do anything or if i use translate( vec3 ) on a simple sphere on a plane, he moves but don't update his position with gravity. Do I have forget something ? T...

I'm looking for confirmation/clarification of how I think manifold contact points work. From testing and from what I've read, it seems that a manifold (btPersistentManifold) is created for 2 bodies as long as their aabb's overlap. I also understand that if the manifold has no contact points, the ac...

Yes, but I wanted to understand in which cases a collision pair (or, better, different collision pairs) with the same two collision objects can appear more than once in the contact manifolds (can it happen only if at least one of them is compound shaped?). Have you understood what I mean? This info...

btCollisionObject* obA = static_cast<btCollisionObject*>(contactManifold->getBody0()); btCollisionObject* obB = static_cast<btCollisionObject*>(contactManifold->getBody1()); What I do is to check which object it is. I suppose "Custom collision filtering" is another possible solution, but ...

As far as I know there can be as many as 4 contact points per contact between two collision shapes Just to be check if my previous understanding is the same as you. A collision pair can have several collision manifold, while each manifold can only contain maximum 4 points. If it is wrong, could any...

Does it mean that you only keep 1 manifold for per collision pair? Yes and no. I have my own collision reporting system I've built on top of bullet. The internal manifolds are preserved, I don't mess around with that because well...that wouldn't work. But I only create a new collision "report&...

After I initially posted I realized I kinda do have a way of addressing it which is what you are getting at. I do not recommend this way (which is why I posted) but currently I have a class that stores a pair of objects and another class that stores collision data. When a manifold is made I make th...

Thanks Dr.Shepherd! So if I was only interested if two objects collided once, whats is the proposed way of ignoring the extra manifolds? If you are specifically focusing on two objects, or one objects with some other objects, you may look into the btGhostObject. Collisionflags would be helpful as w...