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restore behaviors of btSoftBody

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This commit is contained in:
Xuchen Han
2019-08-06 10:52:19 -07:00
parent 6a599bde87
commit e5231b5cc5
9 changed files with 221 additions and 113 deletions
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1
examples/DeformableContact/DeformableContact.cpp
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@@ -228,6 +228,7 @@ void DeformableContact::initPhysics()
psb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
psb->m_cfg.kCHR = 1; // collision hardness with rigid body
psb->m_cfg.kDF = .1;
psb->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;
getDeformableDynamicsWorld()->addSoftBody(psb);
getDeformableDynamicsWorld()->addForce(psb, new btDeformableMassSpringForce());
getDeformableDynamicsWorld()->addForce(psb, new btDeformableGravityForce(gravity));

1
examples/DeformableDemo/DeformableDemo.cpp
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@@ -235,6 +235,7 @@ void DeformableDemo::initPhysics()
psb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
psb->m_cfg.kCHR = 1; // collision hardness with rigid body
psb->m_cfg.kDF = 1;
psb->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;
getDeformableDynamicsWorld()->addSoftBody(psb);
getDeformableDynamicsWorld()->addForce(psb, new btDeformableMassSpringForce());
getDeformableDynamicsWorld()->addForce(psb, new btDeformableGravityForce(gravity));

1
examples/Pinch/Pinch.cpp
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@@ -342,6 +342,7 @@ void Pinch::initPhysics()
psb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
psb->m_cfg.kCHR = 1; // collision hardness with rigid body
psb->m_cfg.kDF = 2;
psb->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;
getDeformableDynamicsWorld()->addSoftBody(psb);
getDeformableDynamicsWorld()->addForce(psb, new btDeformableMassSpringForce());
getDeformableDynamicsWorld()->addForce(psb, new btDeformableGravityForce(gravity));

1
examples/VolumetricDeformable/VolumetricDeformable.cpp
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@@ -241,6 +241,7 @@ void VolumetricDeformable::initPhysics()
psb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
psb->m_cfg.kCHR = 1; // collision hardness with rigid body
psb->m_cfg.kDF = 0.5;
psb->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;
getDeformableDynamicsWorld()->addForce(psb, new btDeformableMassSpringForce());
getDeformableDynamicsWorld()->addForce(psb, new btDeformableGravityForce(gravity));
}

1
src/BulletSoftBody/btDeformableBackwardEulerObjective.h
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@@ -26,7 +26,6 @@ class btDeformableRigidDynamicsWorld;
class btDeformableBackwardEulerObjective
{
public:
// using TVStack = btAlignedObjectArray<btVector3>;
typedef btAlignedObjectArray<btVector3> TVStack;
btScalar m_dt;
btDeformableRigidDynamicsWorld* m_world;

3
src/BulletSoftBody/btDeformableBodySolver.cpp
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@@ -75,7 +75,6 @@ void btDeformableBodySolver::setWorld(btDeformableRigidDynamicsWorld* world)
void btDeformableBodySolver::updateVelocity()
{
// serial implementation
int counter = 0;
for (int i = 0; i < m_softBodySet.size(); ++i)
{
@@ -90,7 +89,6 @@ void btDeformableBodySolver::updateVelocity()
void btDeformableBodySolver::backupVelocity()
{
// serial implementation
int counter = 0;
for (int i = 0; i < m_softBodySet.size(); ++i)
{
@@ -104,7 +102,6 @@ void btDeformableBodySolver::backupVelocity()
void btDeformableBodySolver::revertVelocity()
{
// serial implementation
int counter = 0;
for (int i = 0; i < m_softBodySet.size(); ++i)
{

258
src/BulletSoftBody/btSoftBody.cpp
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@@ -1758,115 +1758,115 @@ void btSoftBody::setSolver(eSolverPresets::_ preset)
}
}
//
void btSoftBody::predictMotion(btScalar dt)
{
int i, ni;
int i, ni;
/* Update */
if (m_bUpdateRtCst)
{
m_bUpdateRtCst = false;
updateConstants();
m_fdbvt.clear();
if (m_cfg.collisions & fCollision::VF_SS)
{
initializeFaceTree();
}
}
/* Update */
if (m_bUpdateRtCst)
{
m_bUpdateRtCst = false;
updateConstants();
m_fdbvt.clear();
if (m_cfg.collisions & fCollision::VF_SS)
{
initializeFaceTree();
}
}
/* Prepare */
m_sst.sdt = dt * m_cfg.timescale;
m_sst.isdt = 1 / m_sst.sdt;
m_sst.velmrg = m_sst.sdt * 3;
m_sst.radmrg = getCollisionShape()->getMargin();
m_sst.updmrg = m_sst.radmrg * (btScalar)0.25;
/* Forces */
// addVelocity(m_worldInfo->m_gravity * m_sst.sdt);
applyForces();
/* Integrate */
for (i = 0, ni = m_nodes.size(); i < ni; ++i)
{
Node& n = m_nodes[i];
n.m_q = n.m_x;
btVector3 deltaV = n.m_f * n.m_im * m_sst.sdt;
{
btScalar maxDisplacement = m_worldInfo->m_maxDisplacement;
btScalar clampDeltaV = maxDisplacement / m_sst.sdt;
for (int c = 0; c < 3; c++)
{
if (deltaV[c] > clampDeltaV)
{
deltaV[c] = clampDeltaV;
}
if (deltaV[c] < -clampDeltaV)
{
deltaV[c] = -clampDeltaV;
}
}
}
/* Prepare */
m_sst.sdt = dt * m_cfg.timescale;
m_sst.isdt = 1 / m_sst.sdt;
m_sst.velmrg = m_sst.sdt * 3;
m_sst.radmrg = getCollisionShape()->getMargin();
m_sst.updmrg = m_sst.radmrg * (btScalar)0.25;
/* Forces */
addVelocity(m_worldInfo->m_gravity * m_sst.sdt);
applyForces();
/* Integrate */
for (i = 0, ni = m_nodes.size(); i < ni; ++i)
{
Node& n = m_nodes[i];
n.m_q = n.m_x;
btVector3 deltaV = n.m_f * n.m_im * m_sst.sdt;
{
btScalar maxDisplacement = m_worldInfo->m_maxDisplacement;
btScalar clampDeltaV = maxDisplacement / m_sst.sdt;
for (int c = 0; c < 3; c++)
{
if (deltaV[c] > clampDeltaV)
{
deltaV[c] = clampDeltaV;
}
if (deltaV[c] < -clampDeltaV)
{
deltaV[c] = -clampDeltaV;
}
}
}
n.m_v += deltaV;
n.m_x += n.m_v * m_sst.sdt;
n.m_f = btVector3(0, 0, 0);
}
/* Clusters */
updateClusters();
/* Bounds */
updateBounds();
/* Nodes */
ATTRIBUTE_ALIGNED16(btDbvtVolume)
vol;
for (i = 0, ni = m_nodes.size(); i < ni; ++i)
{
Node& n = m_nodes[i];
vol = btDbvtVolume::FromCR(n.m_x, m_sst.radmrg);
m_ndbvt.update(n.m_leaf,
vol,
n.m_v * m_sst.velmrg,
m_sst.updmrg);
}
/* Faces */
if (!m_fdbvt.empty())
{
for (int i = 0; i < m_faces.size(); ++i)
{
Face& f = m_faces[i];
const btVector3 v = (f.m_n[0]->m_v +
f.m_n[1]->m_v +
f.m_n[2]->m_v) /
3;
vol = VolumeOf(f, m_sst.radmrg);
m_fdbvt.update(f.m_leaf,
vol,
v * m_sst.velmrg,
m_sst.updmrg);
}
}
/* Pose */
updatePose();
/* Match */
if (m_pose.m_bframe && (m_cfg.kMT > 0))
{
const btMatrix3x3 posetrs = m_pose.m_rot;
for (int i = 0, ni = m_nodes.size(); i < ni; ++i)
{
Node& n = m_nodes[i];
if (n.m_im > 0)
{
const btVector3 x = posetrs * m_pose.m_pos[i] + m_pose.m_com;
n.m_x = Lerp(n.m_x, x, m_cfg.kMT);
}
}
}
/* Clear contacts */
m_rcontacts.resize(0);
m_scontacts.resize(0);
/* Optimize dbvt's */
m_ndbvt.optimizeIncremental(1);
m_fdbvt.optimizeIncremental(1);
m_cdbvt.optimizeIncremental(1);
n.m_f = btVector3(0, 0, 0);
}
/* Clusters */
updateClusters();
/* Bounds */
updateBounds();
/* Nodes */
ATTRIBUTE_ALIGNED16(btDbvtVolume)
vol;
for (i = 0, ni = m_nodes.size(); i < ni; ++i)
{
Node& n = m_nodes[i];
vol = btDbvtVolume::FromCR(n.m_x, m_sst.radmrg);
m_ndbvt.update(n.m_leaf,
vol,
n.m_v * m_sst.velmrg,
m_sst.updmrg);
}
/* Faces */
if (!m_fdbvt.empty())
{
for (int i = 0; i < m_faces.size(); ++i)
{
Face& f = m_faces[i];
const btVector3 v = (f.m_n[0]->m_v +
f.m_n[1]->m_v +
f.m_n[2]->m_v) /
3;
vol = VolumeOf(f, m_sst.radmrg);
m_fdbvt.update(f.m_leaf,
vol,
v * m_sst.velmrg,
m_sst.updmrg);
}
}
/* Pose */
updatePose();
/* Match */
if (m_pose.m_bframe && (m_cfg.kMT > 0))
{
const btMatrix3x3 posetrs = m_pose.m_rot;
for (int i = 0, ni = m_nodes.size(); i < ni; ++i)
{
Node& n = m_nodes[i];
if (n.m_im > 0)
{
const btVector3 x = posetrs * m_pose.m_pos[i] + m_pose.m_com;
n.m_x = Lerp(n.m_x, x, m_cfg.kMT);
}
}
}
/* Clear contacts */
m_rcontacts.resize(0);
m_scontacts.resize(0);
/* Optimize dbvt's */
m_ndbvt.optimizeIncremental(1);
m_fdbvt.optimizeIncremental(1);
m_cdbvt.optimizeIncremental(1);
}
//
void btSoftBody::solveConstraints()
{
@@ -2262,8 +2262,35 @@ btVector3 btSoftBody::evaluateCom() const
return (com);
}
//
bool btSoftBody::checkContact(const btCollisionObjectWrapper* colObjWrap,
const btVector3& x,
btScalar margin,
btSoftBody::sCti& cti) const
{
btVector3 nrm;
const btCollisionShape* shp = colObjWrap->getCollisionShape();
// const btRigidBody *tmpRigid = btRigidBody::upcast(colObjWrap->getCollisionObject());
//const btTransform &wtr = tmpRigid ? tmpRigid->getWorldTransform() : colObjWrap->getWorldTransform();
const btTransform& wtr = colObjWrap->getWorldTransform();
//todo: check which transform is needed here
btScalar dst =
m_worldInfo->m_sparsesdf.Evaluate(
wtr.invXform(x),
shp,
nrm,
margin);
if (dst < 0)
{
cti.m_colObj = colObjWrap->getCollisionObject();
cti.m_normal = wtr.getBasis() * nrm;
cti.m_offset = -btDot(cti.m_normal, x - cti.m_normal * dst);
return (true);
}
return (false);
}
//
bool btSoftBody::checkDeformableContact(const btCollisionObjectWrapper* colObjWrap,
const btVector3& x,
btScalar margin,
btSoftBody::sCti& cti, bool predict) const
@@ -3262,6 +3289,33 @@ void btSoftBody::defaultCollisionHandler(const btCollisionObjectWrapper* pcoWrap
collider.ProcessColObj(this, pcoWrap);
}
break;
case fCollision::SDF_RD:
{
btSoftColliders::CollideSDF_RD docollide;
btRigidBody* prb1 = (btRigidBody*)btRigidBody::upcast(pcoWrap->getCollisionObject());
btTransform wtr = pcoWrap->getWorldTransform();
const btTransform ctr = pcoWrap->getWorldTransform();
const btScalar timemargin = (wtr.getOrigin() - ctr.getOrigin()).length();
const btScalar basemargin = getCollisionShape()->getMargin();
btVector3 mins;
btVector3 maxs;
ATTRIBUTE_ALIGNED16(btDbvtVolume)
volume;
pcoWrap->getCollisionShape()->getAabb(pcoWrap->getWorldTransform(),
mins,
maxs);
volume = btDbvtVolume::FromMM(mins, maxs);
volume.Expand(btVector3(basemargin, basemargin, basemargin));
docollide.psb = this;
docollide.m_colObj1Wrap = pcoWrap;
docollide.m_rigidBody = prb1;
docollide.dynmargin = basemargin + timemargin;
docollide.stamargin = basemargin;
m_ndbvt.collideTV(m_ndbvt.m_root, volume, docollide);
}
break;
}
}

4
src/BulletSoftBody/btSoftBody.h
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@@ -160,6 +160,7 @@ public:
RVSmask = 0x000f, ///Rigid versus soft mask
SDF_RS = 0x0001, ///SDF based rigid vs soft
CL_RS = 0x0002, ///Cluster vs convex rigid vs soft
SDF_RD = 0x0003, ///DF based rigid vs deformable
SVSmask = 0x0030, ///Rigid versus soft mask
VF_SS = 0x0010, ///Vertex vs face soft vs soft handling
@@ -1006,7 +1007,8 @@ public:
btScalar& mint, eFeature::_& feature, int& index, bool bcountonly) const;
void initializeFaceTree();
btVector3 evaluateCom() const;
bool checkContact(const btCollisionObjectWrapper* colObjWrap, const btVector3& x, btScalar margin, btSoftBody::sCti& cti, bool predict = false) const;
bool checkDeformableContact(const btCollisionObjectWrapper* colObjWrap, const btVector3& x, btScalar margin, btSoftBody::sCti& cti, bool predict = false) const;
bool checkContact(const btCollisionObjectWrapper* colObjWrap, const btVector3& x, btScalar margin, btSoftBody::sCti& cti) const;
void updateNormals();
void updateBounds();
void updatePose();

60
src/BulletSoftBody/btSoftBodyInternals.h
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@@ -928,10 +928,62 @@ struct btSoftColliders
psa->m_cdbvt.collideTT(psa->m_cdbvt.m_root, psb->m_cdbvt.m_root, *this);
}
};
//
// CollideSDF_RS
//
struct CollideSDF_RS : btDbvt::ICollide
{
void Process(const btDbvtNode* leaf)
{
btSoftBody::Node* node = (btSoftBody::Node*)leaf->data;
DoNode(*node);
}
void DoNode(btSoftBody::Node& n) const
{
const btScalar m = n.m_im > 0 ? dynmargin : stamargin;
btSoftBody::RContact c;
if ((!n.m_battach) &&
psb->checkContact(m_colObj1Wrap, n.m_x, m, c.m_cti))
{
const btScalar ima = n.m_im;
const btScalar imb = m_rigidBody ? m_rigidBody->getInvMass() : 0.f;
const btScalar ms = ima + imb;
if (ms > 0)
{
const btTransform& wtr = m_rigidBody ? m_rigidBody->getWorldTransform() : m_colObj1Wrap->getCollisionObject()->getWorldTransform();
static const btMatrix3x3 iwiStatic(0, 0, 0, 0, 0, 0, 0, 0, 0);
const btMatrix3x3& iwi = m_rigidBody ? m_rigidBody->getInvInertiaTensorWorld() : iwiStatic;
const btVector3 ra = n.m_x - wtr.getOrigin();
const btVector3 va = m_rigidBody ? m_rigidBody->getVelocityInLocalPoint(ra) * psb->m_sst.sdt : btVector3(0, 0, 0);
const btVector3 vb = n.m_x - n.m_q;
const btVector3 vr = vb - va;
const btScalar dn = btDot(vr, c.m_cti.m_normal);
const btVector3 fv = vr - c.m_cti.m_normal * dn;
const btScalar fc = psb->m_cfg.kDF * m_colObj1Wrap->getCollisionObject()->getFriction();
c.m_node = &n;
c.m_c0 = ImpulseMatrix(psb->m_sst.sdt, ima, imb, iwi, ra);
c.m_c1 = ra;
c.m_c2 = ima * psb->m_sst.sdt;
c.m_c3 = fv.length2() < (dn * fc * dn * fc) ? 0 : 1 - fc;
c.m_c4 = m_colObj1Wrap->getCollisionObject()->isStaticOrKinematicObject() ? psb->m_cfg.kKHR : psb->m_cfg.kCHR;
psb->m_rcontacts.push_back(c);
if (m_rigidBody)
m_rigidBody->activate();
}
}
}
btSoftBody* psb;
const btCollisionObjectWrapper* m_colObj1Wrap;
btRigidBody* m_rigidBody;
btScalar dynmargin;
btScalar stamargin;
};
//
// CollideSDF_RS
// CollideSDF_RD
//
struct CollideSDF_RS : btDbvt::ICollide
struct CollideSDF_RD : btDbvt::ICollide
{
void Process(const btDbvtNode* leaf)
{
@@ -946,7 +998,7 @@ struct btSoftColliders
if (!n.m_battach)
{
// check for collision at x_{n+1}^*
if (psb->checkContact(m_colObj1Wrap, n.m_x, m, c.m_cti, /*predicted = */ true))
if (psb->checkDeformableContact(m_colObj1Wrap, n.m_x, m, c.m_cti, /*predicted = */ true))
{
const btScalar ima = n.m_im;
const btScalar imb = m_rigidBody ? m_rigidBody->getInvMass() : 0.f;
@@ -954,7 +1006,7 @@ struct btSoftColliders
if (ms > 0)
{
// resolve contact at x_n
psb->checkContact(m_colObj1Wrap, n.m_q, m, c.m_cti, /*predicted = */ false);
psb->checkDeformableContact(m_colObj1Wrap, n.m_q, m, c.m_cti, /*predicted = */ false);
btSoftBody::sCti& cti = c.m_cti;
c.m_node = &n;
const btScalar fc = psb->m_cfg.kDF * m_colObj1Wrap->getCollisionObject()->getFriction();