export contact friction/damping through URDF and API

convert from contact friction/damping to cfm/erp
btCollisionObject::setContactFrictionAndDamping
This commit is contained in:
Erwin Coumans
2016-09-02 16:40:56 -07:00
parent 23f7293a25
commit ecd814c9c5
19 changed files with 269 additions and 125 deletions

View File

@@ -25,7 +25,7 @@ ContactAddedCallback gContactAddedCallback=0;
///User can override this material combiner by implementing gContactAddedCallback and setting body0->m_collisionFlags |= btCollisionObject::customMaterialCallback;
inline btScalar calculateCombinedRollingFriction(const btCollisionObject* body0,const btCollisionObject* body1)
btScalar btManifoldResult::calculateCombinedRollingFriction(const btCollisionObject* body0,const btCollisionObject* body1)
{
btScalar friction = body0->getRollingFriction() * body1->getRollingFriction();
@@ -58,6 +58,22 @@ btScalar btManifoldResult::calculateCombinedRestitution(const btCollisionObject*
return body0->getRestitution() * body1->getRestitution();
}
btScalar btManifoldResult::calculateCombinedContactDamping(const btCollisionObject* body0,const btCollisionObject* body1)
{
return body0->getContactDamping() + body1->getContactDamping();
}
btScalar btManifoldResult::calculateCombinedContactStiffness(const btCollisionObject* body0,const btCollisionObject* body1)
{
btScalar s0 = body0->getContactStiffness();
btScalar s1 = body1->getContactStiffness();
btScalar tmp0 = btScalar(1)/s0;
btScalar tmp1 = btScalar(1)/s1;
btScalar combinedStiffness = btScalar(1) / (tmp0+tmp1);
return combinedStiffness;
}
btManifoldResult::btManifoldResult(const btCollisionObjectWrapper* body0Wrap,const btCollisionObjectWrapper* body1Wrap)
@@ -109,6 +125,15 @@ void btManifoldResult::addContactPoint(const btVector3& normalOnBInWorld,const b
newPt.m_combinedFriction = calculateCombinedFriction(m_body0Wrap->getCollisionObject(),m_body1Wrap->getCollisionObject());
newPt.m_combinedRestitution = calculateCombinedRestitution(m_body0Wrap->getCollisionObject(),m_body1Wrap->getCollisionObject());
newPt.m_combinedRollingFriction = calculateCombinedRollingFriction(m_body0Wrap->getCollisionObject(),m_body1Wrap->getCollisionObject());
if ( (m_body0Wrap->getCollisionObject()->getCollisionFlags()& btCollisionObject::CF_HAS_CONTACT_STIFFNESS_DAMPING) ||
(m_body1Wrap->getCollisionObject()->getCollisionFlags()& btCollisionObject::CF_HAS_CONTACT_STIFFNESS_DAMPING))
{
newPt.m_combinedContactDamping1 = calculateCombinedContactDamping(m_body0Wrap->getCollisionObject(),m_body1Wrap->getCollisionObject());
newPt.m_combinedContactStiffness1 = calculateCombinedContactStiffness(m_body0Wrap->getCollisionObject(),m_body1Wrap->getCollisionObject());
newPt.m_contactPointFlags |= BT_CONTACT_FLAG_CONTACT_STIFFNESS_DAMPING;
}
btPlaneSpace1(newPt.m_normalWorldOnB,newPt.m_lateralFrictionDir1,newPt.m_lateralFrictionDir2);