diff options
-rw-r--r-- | examples/SharedMemory/PhysicsServerCommandProcessor.cpp | 121 | ||||
-rw-r--r-- | src/BulletSoftBody/btDeformableContactConstraint.cpp | 5 | ||||
-rw-r--r-- | src/BulletSoftBody/btSoftBody.h | 10 |
3 files changed, 97 insertions, 39 deletions
diff --git a/examples/SharedMemory/PhysicsServerCommandProcessor.cpp b/examples/SharedMemory/PhysicsServerCommandProcessor.cpp index 0d826af41..e949f3e1f 100644 --- a/examples/SharedMemory/PhysicsServerCommandProcessor.cpp +++ b/examples/SharedMemory/PhysicsServerCommandProcessor.cpp @@ -8073,21 +8073,26 @@ bool PhysicsServerCommandProcessor::processRequestDeformableContactpointHelper(c { return false; } - int numSoftbodyContact = 0; - for (int i = deformWorld->getSoftBodyArray().size() - 1; i >= 0; i--) - { - numSoftbodyContact += deformWorld->getSoftBodyArray()[i]->m_faceRigidContacts.size(); - } - int num_contact_points = m_data->m_cachedContactPoints.size(); - m_data->m_cachedContactPoints.reserve(num_contact_points + numSoftbodyContact); for (int i = deformWorld->getSoftBodyArray().size() - 1; i >= 0; i--) { btSoftBody* psb = deformWorld->getSoftBodyArray()[i]; + btAlignedObjectArray<b3ContactPointData> distinctContactPoints; + btAlignedObjectArray<btSoftBody::Node*> nodesInContact; for (int c = 0; c < psb->m_faceRigidContacts.size(); c++) { - const btSoftBody::DeformableFaceRigidContact* contact = &psb->m_faceRigidContacts[i]; - //convert rigidbody contact + const btSoftBody::DeformableFaceRigidContact* contact = &psb->m_faceRigidContacts[c]; + // calculate normal and tangent impulse + btVector3 impulse = contact->m_cti.m_impulse; + btVector3 impulseNormal = impulse.dot(contact->m_cti.m_normal) * contact->m_cti.m_normal; + btVector3 impulseTangent = impulse - impulseNormal; + // get node in contact + int contactNodeIdx = contact->m_bary.maxAxis(); + btSoftBody::Node* node = contact->m_face->m_n[contactNodeIdx]; + // check if node is already in the list + int idx = nodesInContact.findLinearSearch2(node); + + //apply the filter, if the user provides it int linkIndexA = -1; int linkIndexB = -1; int objectIndexA = psb->getUserIndex2(); @@ -8104,8 +8109,6 @@ bool PhysicsServerCommandProcessor::processRequestDeformableContactpointHelper(c linkIndexB = mblB->m_link; objectIndexB = mblB->m_multiBody->getUserIndex2(); } - - //apply the filter, if the user provides it bool swap = false; if (clientCmd.m_requestContactPointArguments.m_objectAIndexFilter >= 0) { @@ -8151,37 +8154,87 @@ bool PhysicsServerCommandProcessor::processRequestDeformableContactpointHelper(c { continue; } - b3ContactPointData pt; - pt.m_bodyUniqueIdA = objectIndexA; - pt.m_bodyUniqueIdB = objectIndexB; - pt.m_contactDistance = contact->m_cti.m_offset; - pt.m_contactFlags = 0; - pt.m_linkIndexA = linkIndexA; - pt.m_linkIndexB = linkIndexB; - for (int j = 0; j < 3; j++) + + if (idx < 0) { - if (swap) + // add new node and contact point + nodesInContact.push_back(node); + b3ContactPointData pt; + pt.m_bodyUniqueIdA = objectIndexA; + pt.m_bodyUniqueIdB = objectIndexB; + pt.m_contactDistance = -contact->m_cti.m_offset; + pt.m_contactFlags = 0; + pt.m_linkIndexA = linkIndexA; + pt.m_linkIndexB = linkIndexB; + for (int j = 0; j < 3; j++) { - pt.m_contactNormalOnBInWS[j] = -contact->m_cti.m_normal[j]; - pt.m_positionOnAInWS[j] = contact->m_cti.m_normal[j]; - pt.m_positionOnBInWS[j] = -contact->m_cti.m_normal[j]; + if (swap) + { + pt.m_contactNormalOnBInWS[j] = -contact->m_cti.m_normal[j]; + pt.m_positionOnAInWS[j] = node->m_x[j] - pt.m_contactDistance * pt.m_contactNormalOnBInWS[j]; // not really precise because of margins in btSoftBody.cpp:line 2912 + // node is force application point, therefore node position is contact point (not contact->m_contactPoint, because not equal to node) + pt.m_positionOnBInWS[j] = node->m_x[j]; + } + else + { + pt.m_contactNormalOnBInWS[j] = contact->m_cti.m_normal[j]; + // node is force application point, therefore node position is contact point (not contact->m_contactPoint, because not equal to node) + pt.m_positionOnAInWS[j] = node->m_x[j]; + pt.m_positionOnBInWS[j] = node->m_x[j] - pt.m_contactDistance * pt.m_contactNormalOnBInWS[j]; // not really precise because of margins in btSoftBody.cpp:line 2912 + } } - else + pt.m_normalForce = (impulseNormal / m_data->m_physicsDeltaTime).norm(); + pt.m_linearFrictionForce1 = (impulseTangent.dot(contact->t1) * contact->t1 / m_data->m_physicsDeltaTime).norm(); + pt.m_linearFrictionForce2 = (impulseTangent.dot(contact->t2) * contact->t2 / m_data->m_physicsDeltaTime).norm(); + for (int j = 0; j < 3; j++) { - pt.m_contactNormalOnBInWS[j] = contact->m_cti.m_normal[j]; - pt.m_positionOnAInWS[j] = -contact->m_cti.m_normal[j]; - pt.m_positionOnBInWS[j] = contact->m_cti.m_normal[j]; + pt.m_linearFrictionDirection1[j] = contact->t1[j]; + pt.m_linearFrictionDirection2[j] = contact->t2[j]; } + distinctContactPoints.push_back(pt); } - pt.m_normalForce = 1; - pt.m_linearFrictionForce1 = 0; - pt.m_linearFrictionForce2 = 0; - for (int j = 0; j < 3; j++) + else { - pt.m_linearFrictionDirection1[j] = 0; - pt.m_linearFrictionDirection2[j] = 0; + // add values to existing contact point + b3ContactPointData* pt = &distinctContactPoints[idx]; + // current normal force of node + btVector3 normalForce = btVector3(btScalar(pt->m_contactNormalOnBInWS[0]), + btScalar(pt->m_contactNormalOnBInWS[1]), + btScalar(pt->m_contactNormalOnBInWS[2])) * pt->m_normalForce; + // add normal force of additional node contact + btScalar swapFactor = swap ? -1.0 : 1.0; + normalForce += swapFactor * contact->m_cti.m_normal * (impulseNormal / m_data->m_physicsDeltaTime).norm(); + // get magnitude of normal force + pt->m_normalForce = normalForce.norm(); + // get direction of normal force + if (!normalForce.fuzzyZero()) + { + // normalize for unit vectors if above numerical threshold + normalForce.normalize(); + for (int j = 0; j < 3; j++) + { + pt->m_contactNormalOnBInWS[j] = normalForce[j]; + } + } + + // add magnitudes of tangential forces in existing directions + btVector3 linearFrictionDirection1 = btVector3(btScalar(pt->m_linearFrictionDirection1[0]), + btScalar(pt->m_linearFrictionDirection1[1]), + btScalar(pt->m_linearFrictionDirection1[2])); + btVector3 linearFrictionDirection2 = btVector3(btScalar(pt->m_linearFrictionDirection2[0]), + btScalar(pt->m_linearFrictionDirection2[1]), + btScalar(pt->m_linearFrictionDirection2[2])); + pt->m_linearFrictionForce1 = (impulseTangent.dot(linearFrictionDirection1) * linearFrictionDirection1 / m_data->m_physicsDeltaTime).norm(); + pt->m_linearFrictionForce2 = (impulseTangent.dot(linearFrictionDirection2) * linearFrictionDirection2 / m_data->m_physicsDeltaTime).norm(); } - m_data->m_cachedContactPoints.push_back(pt); + } + + int num_contact_points = m_data->m_cachedContactPoints.size() + distinctContactPoints.size(); + m_data->m_cachedContactPoints.reserve(num_contact_points); + // add points to contact points cache + for (int p = 0; p < distinctContactPoints.size(); p++) + { + m_data->m_cachedContactPoints.push_back(distinctContactPoints[p]); } } #endif diff --git a/src/BulletSoftBody/btDeformableContactConstraint.cpp b/src/BulletSoftBody/btDeformableContactConstraint.cpp index 09398d79a..9c8e72f50 100644 --- a/src/BulletSoftBody/btDeformableContactConstraint.cpp +++ b/src/BulletSoftBody/btDeformableContactConstraint.cpp @@ -268,7 +268,7 @@ btScalar btDeformableRigidContactConstraint::solveConstraint(const btContactSolv { dn += m_penetration * infoGlobal.m_deformable_erp / infoGlobal.m_timeStep; } - // dn is the normal component of velocity diffrerence. Approximates the residual. // todo xuchenhan@: this prob needs to be scaled by dt + // dn is the normal component of velocity difference. Approximates the residual. // todo xuchenhan@: this prob needs to be scaled by dt btVector3 impulse = m_contact->m_c0 * (vr + m_total_normal_dv * infoGlobal.m_deformable_cfm + ((m_penetration > 0) ? m_penetration / infoGlobal.m_timeStep * cti.m_normal : btVector3(0, 0, 0))); if (!infoGlobal.m_splitImpulse) { @@ -487,6 +487,9 @@ void btDeformableFaceRigidContactConstraint::applyImpulse(const btVector3& impul btVector3 dv = impulse * contact->m_c2; btSoftBody::Face* face = contact->m_face; + // save applied impulse + contact->m_cti.m_impulse = impulse; + btVector3& v0 = face->m_n[0]->m_v; btVector3& v1 = face->m_n[1]->m_v; btVector3& v2 = face->m_n[2]->m_v; diff --git a/src/BulletSoftBody/btSoftBody.h b/src/BulletSoftBody/btSoftBody.h index d5b01faf3..cee3ae0f2 100644 --- a/src/BulletSoftBody/btSoftBody.h +++ b/src/BulletSoftBody/btSoftBody.h @@ -223,10 +223,12 @@ public: /* sCti is Softbody contact info */ struct sCti { - const btCollisionObject* m_colObj; /* Rigid body */ - btVector3 m_normal; /* Outward normal */ - btScalar m_offset; /* Offset from origin */ + const btCollisionObject* m_colObj; /* Rigid body */ + btVector3 m_normal; /* Outward normal */ + mutable btVector3 m_impulse; /* Applied impulse */ + btScalar m_offset; /* Offset from origin */ btVector3 m_bary; /* Barycentric weights for faces */ + sCti() : m_impulse(0, 0, 0) {} }; /* sMedium */ @@ -892,7 +894,7 @@ public: int node1) const; bool checkLink(const Node* node0, const Node* node1) const; - /* Check for existring face */ + /* Check for existing face */ bool checkFace(int node0, int node1, int node2) const; |