I'm trying to simulate friction based grasping, with a simple grasping tool grasping that consists of a (vertical) shaft with two jaws. The grasper comes down to grasp a sphere as depicted in ascii below ( going through the steps 1,2, and unfortunately not 3 )
Code: Select all
1 2 3
| |
| | |
/ \ | /o\
o /o\
The ball moves as if there is no friction, it does not even lift a little bit and I can not figure out why. The ball just goes out of the jaws when the jaws close.
- the code is based on the MotorDemo ( spiders )
- I changed the solver to the Dantzig solver
- all bodies have friction and rollingFriction coefficient 1.0
- all bodies have restitution of 0
- solver numIterations is set to 500
- internal time step is 0.002.
- to prevent difficult geometry ( normal force working to push the ball out ), the hinges are offset horizontally and the max angle of each jaw to the vertical is 30 degrees, and in practice less
Does anybody have any idea what could be wrong? Any help or suggestions would be greatly appreciated.
Thanks!
Update 25-11: According to the following thread, stopping the motors may do the trick. http://bulletphysics.org/Bullet/phpBB3/ ... ion#p34013 So far I did not get improved results, the motors stop and continue, and stop, etc. as the contact is a bit jittery it seems.