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allow multiple reduced deformable object in one sim

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This commit is contained in:
Jingyu Chen
2021-12-09 16:55:10 -05:00
parent 1feb81463a
commit f19133e410
6 changed files with 68 additions and 12 deletions
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32
examples/ReducedDeformableDemo/FreeFall.cpp
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@@ -152,6 +152,8 @@ void FreeFall::initPhysics()
rsb->getCollisionShape()->setMargin(0.01);
// rsb->scale(btVector3(1, 1, 0.5));
rsb->setTotalMass(10);
btTransform init_transform;
init_transform.setIdentity();
init_transform.setOrigin(btVector3(0, 4, 0));
@@ -160,8 +162,38 @@ void FreeFall::initPhysics()
rsb->setStiffnessScale(5);
rsb->setDamping(damping_alpha, damping_beta);
// rsb->scale(btVector3(0.5, 0.5, 0.5));
rsb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
rsb->m_cfg.kCHR = 1; // collision hardness with rigid body
rsb->m_cfg.kDF = 0;
rsb->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;
rsb->m_cfg.collisions |= btSoftBody::fCollision::SDF_RDN;
rsb->m_sleepingThreshold = 0;
btSoftBodyHelpers::generateBoundaryFaces(rsb);
// rsb->setVelocity(btVector3(0, -COLLIDING_VELOCITY, 0));
// rsb->setRigidVelocity(btVector3(0, 0, 1));
// rsb->setRigidAngularVelocity(btVector3(1, 0, 0));
}
{
btReducedSoftBody* rsb = btReducedSoftBodyHelpers::createReducedTorus(getDeformableDynamicsWorld()->getWorldInfo(), num_modes);
getDeformableDynamicsWorld()->addSoftBody(rsb);
rsb->getCollisionShape()->setMargin(0.01);
// rsb->scale(btVector3(1, 1, 0.5));
rsb->setTotalMass(10);
btTransform init_transform;
init_transform.setIdentity();
init_transform.setOrigin(btVector3(4, 4, 0));
init_transform.setRotation(btQuaternion(SIMD_PI / 2.0, SIMD_PI / 2.0, 0));
rsb->transformTo(init_transform);
rsb->setStiffnessScale(5);
rsb->setDamping(damping_alpha, damping_beta);
// rsb->scale(btVector3(0.5, 0.5, 0.5));
rsb->m_cfg.kKHR = 1; // collision hardness with kinematic objects

24
src/BulletSoftBody/BulletReducedSoftBody/btReducedDeformableContactConstraint.cpp
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@@ -63,6 +63,7 @@ btReducedDeformableRigidContactConstraint::btReducedDeformableRigidContactConstr
btScalar dt)
: m_rsb(rsb), m_dt(dt), btDeformableRigidContactConstraint(c, infoGlobal)
{
m_nodeQueryIndex = 0;
m_appliedNormalImpulse = 0;
m_appliedTangentImpulse = 0;
m_rhs = 0;
@@ -326,6 +327,15 @@ btReducedDeformableNodeRigidContactConstraint::btReducedDeformableNodeRigidConta
m_contactNormalA = contact.m_cti.m_normal;
m_contactNormalB = -contact.m_cti.m_normal;
if (contact.m_node->index < rsb->m_nodes.size())
{
m_nodeQueryIndex = contact.m_node->index;
}
else
{
m_nodeQueryIndex = m_node->index - rsb->m_nodeIndexOffset;
}
if (m_contact->m_cti.m_colObj->getInternalType() == btCollisionObject::CO_RIGID_BODY)
{
m_relPosA = contact.m_c1;
@@ -338,11 +348,11 @@ btReducedDeformableNodeRigidContactConstraint::btReducedDeformableNodeRigidConta
if (m_collideStatic) // colliding with static object, only consider reduced deformable body's impulse factor
{
m_impulseFactor = m_rsb->getImpulseFactor(m_node->index);
m_impulseFactor = m_rsb->getImpulseFactor(m_nodeQueryIndex);
}
else // colliding with dynamic object, consider both reduced deformable and rigid body's impulse factors
{
m_impulseFactor = m_rsb->getImpulseFactor(m_node->index) + contact.m_c0;
m_impulseFactor = m_rsb->getImpulseFactor(m_nodeQueryIndex) + contact.m_c0;
}
m_normalImpulseFactor = (m_impulseFactor * m_contactNormalA).dot(m_contactNormalA);
@@ -374,9 +384,13 @@ void btReducedDeformableNodeRigidContactConstraint::warmStarting()
if (!m_collideMultibody)
{
m_contactTangent = v_tangent.normalized();
// tangent impulse factor
m_contactTangent2.setZero();
// tangent impulse factor 1
m_tangentImpulseFactor = (m_impulseFactor * m_contactTangent).dot(m_contactTangent);
m_tangentImpulseFactorInv = btScalar(1) / m_tangentImpulseFactor;
// tangent impulse factor 2
m_tangentImpulseFactor2 = 0;
m_tangentImpulseFactorInv2 = 0;
}
else // multibody requires 2 contact directions
{
@@ -490,7 +504,7 @@ btVector3 btReducedDeformableNodeRigidContactConstraint::getDeltaVa() const
btVector3 btReducedDeformableNodeRigidContactConstraint::getDeltaVb() const
{
// std::cout << "node: " << m_node->index << '\n';
return m_rsb->internalComputeNodeDeltaVelocity(m_rsb->getInterpolationWorldTransform(), m_node->index);
return m_rsb->internalComputeNodeDeltaVelocity(m_rsb->getInterpolationWorldTransform(), m_nodeQueryIndex);
}
btVector3 btReducedDeformableNodeRigidContactConstraint::getSplitVb() const
@@ -505,7 +519,7 @@ btVector3 btReducedDeformableNodeRigidContactConstraint::getDv(const btSoftBody:
void btReducedDeformableNodeRigidContactConstraint::applyImpulse(const btVector3& impulse)
{
m_rsb->internalApplyFullSpaceImpulse(impulse, m_relPosB, m_node->index, m_dt);
m_rsb->internalApplyFullSpaceImpulse(impulse, m_relPosB, m_nodeQueryIndex, m_dt);
// m_rsb->applyFullSpaceImpulse(impulse, m_relPosB, m_node->index, m_dt);
// m_rsb->mapToFullVelocity(m_rsb->getInterpolationWorldTransform());
// if (!m_collideStatic)

2
src/BulletSoftBody/BulletReducedSoftBody/btReducedDeformableContactConstraint.h
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@@ -44,6 +44,8 @@ class btReducedDeformableRigidContactConstraint : public btDeformableRigidContac
bool m_collideStatic; // flag for collision with static object
bool m_collideMultibody; // flag for collision with multibody
int m_nodeQueryIndex;
btReducedSoftBody* m_rsb;
btSolverBody* m_solverBody;
btScalar m_dt;

1
src/BulletSoftBody/BulletReducedSoftBody/btReducedSoftBody.cpp
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@@ -14,6 +14,7 @@ btReducedSoftBody::btReducedSoftBody(btSoftBodyWorldInfo* worldInfo, int node_co
m_reducedModel = true;
m_nReduced = 0;
m_nFull = 0;
m_nodeIndexOffset = 0;
m_transform_lock = false;
m_ksScale = 1.0;

1
src/BulletSoftBody/BulletReducedSoftBody/btReducedSoftBody.h
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@@ -91,6 +91,7 @@ class btReducedSoftBody : public btSoftBody
TVStack m_x0; // Rest position
tDenseArray m_nodalMass; // Mass on each node
btAlignedObjectArray<int> m_fixedNodes; // index of the fixed nodes
int m_nodeIndexOffset; // offset of the node index needed for contact solver when there are multiple reduced deformable body in the world.
// contacts
btAlignedObjectArray<int> m_contactNodesList;

20
src/BulletSoftBody/BulletReducedSoftBody/btReducedSoftBodySolver.cpp
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@@ -62,6 +62,15 @@ void btReducedSoftBodySolver::reinitialize(const btAlignedObjectArray<btSoftBody
rsb->m_contactNodesList.clear();
}
// set node index offsets
int sum = 0;
for (int i = 0; i < m_softBodies.size(); ++i)
{
btReducedSoftBody* rsb = static_cast<btReducedSoftBody*>(m_softBodies[i]);
rsb->m_nodeIndexOffset = sum;
rsb->m_nodeIndexOffset += rsb->m_nodes.size();
}
btDeformableBodySolver::updateSoftBodies();
}
@@ -182,10 +191,6 @@ void btReducedSoftBodySolver::applyTransforms(btScalar timeStep)
// update the rendering mesh
rsb->interpolateRenderMesh();
}
// static int count = 0;
// if (count > 0) exit(100);
// count++;
}
void btReducedSoftBodySolver::setConstraints(const btContactSolverInfo& infoGlobal)
@@ -226,7 +231,7 @@ void btReducedSoftBodySolver::setConstraints(const btContactSolverInfo& infoGlob
}
btReducedDeformableNodeRigidContactConstraint constraint(rsb, contact, infoGlobal, m_dt);
m_nodeRigidConstraints[i].push_back(constraint);
rsb->m_contactNodesList.push_back(contact.m_node->index);
rsb->m_contactNodesList.push_back(contact.m_node->index - rsb->m_nodeIndexOffset);
}
// std::cout << "contact node list size: " << rsb->m_contactNodesList.size() << "\n";
// std::cout << "#contact nodes: " << m_nodeRigidConstraints[i].size() << "\n";
@@ -274,10 +279,11 @@ btScalar btReducedSoftBodySolver::solveContactConstraints(btCollisionObject** de
{
btScalar residualSquare = 0;
btAlignedObjectArray<int> m_orderNonContactConstraintPool;
btAlignedObjectArray<int> m_orderContactConstraintPool;
for (int i = 0; i < m_softBodies.size(); ++i)
{
btAlignedObjectArray<int> m_orderNonContactConstraintPool;
btAlignedObjectArray<int> m_orderContactConstraintPool;
btReducedSoftBody* rsb = static_cast<btReducedSoftBody*>(m_softBodies[i]);
// shuffle the order of applying constraint