fix issue with btMultiBody friction in combination with soft contacts (friction should not re-use normal contact cfm/erp)

implement friction anchors, position friction correction, disabled by default. Use colObj->setCollisionFlag(flag | CF_HAS_FRICTION_ANCHOR); See test/RobotClientAPI/SlopeFrictionMain.cpp. In URDF or SDF, add <friction_anchor/> in <contact> section of <link> to enable.
PhysicsServer: properly restore old activation state after releasing picked object
btMultiBodyConstraintSolver: disable flip/flop of contact/friction constraint solving by default (it breaks some internal flaky unit tests)
This commit is contained in:
Erwin Coumans
2017-03-20 10:58:07 -07:00
parent 865d37fcb5
commit 0b017b0f53
18 changed files with 299 additions and 91 deletions

View File

@@ -43,10 +43,13 @@ struct btContactSolverInfoData
btScalar m_restitution;
int m_numIterations;
btScalar m_maxErrorReduction;
btScalar m_sor;
btScalar m_erp;//used as Baumgarte factor
btScalar m_erp2;//used in Split Impulse
btScalar m_globalCfm;//constraint force mixing
btScalar m_sor;//successive over-relaxation term
btScalar m_erp;//error reduction for non-contact constraints
btScalar m_erp2;//error reduction for contact constraints
btScalar m_globalCfm;//constraint force mixing for contacts and non-contacts
btScalar m_frictionERP;//error reduction for friction constraints
btScalar m_frictionCFM;//constraint force mixing for friction constraints
int m_splitImpulse;
btScalar m_splitImpulsePenetrationThreshold;
btScalar m_splitImpulseTurnErp;
@@ -79,6 +82,8 @@ struct btContactSolverInfo : public btContactSolverInfoData
m_erp = btScalar(0.2);
m_erp2 = btScalar(0.2);
m_globalCfm = btScalar(0.);
m_frictionERP = btScalar(0.2);//positional friction 'anchors' are disabled by default
m_frictionCFM = btScalar(0.);
m_sor = btScalar(1.);
m_splitImpulse = true;
m_splitImpulsePenetrationThreshold = -.04f;