Weak constraint: btMultiBody to btRigidBody
Posted: Mon Oct 31, 2016 7:06 pm
Test scene: a spherical rigid body (angular factor 0,0,1, mass 400) attached to a multibody using a btMultiBodyFixedConstraint (links of mass 100). Applying forces directly to the sphere, I intend for the sphere to be 'leashed' to the chain in the same way as the links of the multibody.
I've gone ahead and implemented the chain multibody that was created in the example (MultiDofDemo) and it was a clear step up from a chain of constraints I was using before (chain links not stretched/bouncing upon large forces). However, it seems that the constraint between the rigid body and multibody has a less 'hard' relationship in that it appears the constraint pulls the sphere towards it slowly, being pulled even faster if I increase the m_maxAppliedImpulse on the object. I don't see much functionality for the multibody constraints on this issue (such as stiffness maybe?). I'm not aiming for physical accuracy, so breaking some fundamentals to achieve a hard chain would be fine with me.
Chain and fixed constraint while within reach of the chain: ( http://i.imgur.com/xeshhCJ.png ) working as intended.
Chain and fixed constraint while pushing out of reach of the chain: ( http://i.imgur.com/mxOWSUD.png ) chain working as intended, rigid body being affected weakly.
Does anyone have a suggestion on implementing this properly? I'm open to switching to non multibodies as well if that's the better approach.
I've gone ahead and implemented the chain multibody that was created in the example (MultiDofDemo) and it was a clear step up from a chain of constraints I was using before (chain links not stretched/bouncing upon large forces). However, it seems that the constraint between the rigid body and multibody has a less 'hard' relationship in that it appears the constraint pulls the sphere towards it slowly, being pulled even faster if I increase the m_maxAppliedImpulse on the object. I don't see much functionality for the multibody constraints on this issue (such as stiffness maybe?). I'm not aiming for physical accuracy, so breaking some fundamentals to achieve a hard chain would be fine with me.
Chain and fixed constraint while within reach of the chain: ( http://i.imgur.com/xeshhCJ.png ) working as intended.
Chain and fixed constraint while pushing out of reach of the chain: ( http://i.imgur.com/mxOWSUD.png ) chain working as intended, rigid body being affected weakly.
Does anyone have a suggestion on implementing this properly? I'm open to switching to non multibodies as well if that's the better approach.