Search found 7 matches

by quzox
Mon Aug 13, 2012 9:31 pm
Forum: General Bullet Physics Support and Feedback
Topic: noob question: body doesn't fall
Replies: 12
Views: 7327

Re: noob question: body doesn't fall

Going by the code provided it doesn't look like you're inserting the btRigidBody into the dynamics world! :lol: So somewhere in your code there should be a:

dynamicsWorld->addRigidBody(Body);
by quzox
Mon Aug 13, 2012 9:22 pm
Forum: General Bullet Physics Support and Feedback
Topic: Constraints for wheels
Replies: 6
Views: 6247

Re: Constraints for wheels

Zoomulator wrote:Thanks a quzox!
With the slippy tires, maybe you've got too much torque compared to the weight of the "car"?
Very likely, although I've grown used to it now. It's kinda fun too. :D
by quzox
Mon Aug 13, 2012 9:21 pm
Forum: General Bullet Physics Support and Feedback
Topic: Constraints for wheels
Replies: 6
Views: 6247

Re: Constraints for wheels

Hi monkeyman, I think it's still possible although I may have to start toying around with the tyre contact model and giving it special consideration. The frictional force should be proportional to the force along the contact normal (and then bounded at some point) which I'm not sure if Bullet is doi...
by quzox
Thu Aug 02, 2012 12:38 pm
Forum: General Bullet Physics Support and Feedback
Topic: btGeneric6DofConstraint as a motor
Replies: 3
Views: 3947

Re: btGeneric6DofConstraint as a motor

Haven't tried to make a 6dof move with an angular motor but have had some success with the hinge constraint, and given that you only need to rotate around a single axis for the robot leg then a hinge constraint will work. You can even set limits on how far the rotation should be allowed. Actually yo...
by quzox
Wed Aug 01, 2012 11:17 pm
Forum: General Bullet Physics Support and Feedback
Topic: Constraints for wheels
Replies: 6
Views: 6247

Re: Constraints for wheels

Managed to fix the front tyre issue. It's possible to use a Generic6DOF for the front tyres, just lock all 3 linear axes and all angular axes except for the x-axis (because it needs to spin around the x-axis). Then set your upper and lower limits for the y-axis to be equal to the current steering an...
by quzox
Wed Aug 01, 2012 9:43 pm
Forum: General Bullet Physics Support and Feedback
Topic: Constraints for wheels
Replies: 6
Views: 6247

Re: Constraints for wheels

Hiya I'm doing something similar. First thing I got wrong was leaving the localInertia vector to zero for the tyre object (last parameter in the RigidBodyConstructionInfo constructor), which meant it couldn't spin. Just set it to all ones (for both tyre and chassis) and it'll behave as expected. The...
by quzox
Wed Aug 01, 2012 9:20 pm
Forum: General Bullet Physics Support and Feedback
Topic: Gravity seems too weak - object falling too slowly.
Replies: 1
Views: 1737

Re: Gravity seems too weak - object falling too slowly.

Your numbers do work out, also using "vel_post = vel_pre + (accel * time)" setting accel = -10 and time = 0.1 then the velocity should be decreasing by 1 after every call to stepSimulation(0.1f). You can verify that in a debugger, just inspect the numbers inside the RigidBody object. edit: Just trie...