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Merge pull request #2509 from xhan0619/separate-bending-stiffness

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Separate in-plane and bending stiffness for mass spring model
This commit is contained in:
erwincoumans
2019-12-04 07:34:28 -08:00
committed by GitHub
parent c4300dc299 8fde74ecea
commit 44f21e462a
7 changed files with 52 additions and 37 deletions
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5
examples/SharedMemory/PhysicsClientC_API.cpp
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@@ -422,11 +422,12 @@ B3_SHARED_API int b3LoadSoftBodySetFrictionCoefficient(b3SharedMemoryCommandHand
return 0;
}
B3_SHARED_API int b3LoadSoftBodyUseBendingSprings(b3SharedMemoryCommandHandle commandHandle, int useBendingSprings)
B3_SHARED_API int b3LoadSoftBodyUseBendingSprings(b3SharedMemoryCommandHandle commandHandle, int useBendingSprings, double bendingStiffness)
{
struct SharedMemoryCommand* command = (struct SharedMemoryCommand*)commandHandle;
b3Assert(command->m_type == CMD_LOAD_SOFT_BODY);
command->m_loadSoftBodyArguments.m_useBendingSprings = useBendingSprings;
command->m_loadSoftBodyArguments.m_useBendingSprings = useBendingSprings;
command->m_loadSoftBodyArguments.m_springBendingStiffness = bendingStiffness;
command->m_updateFlags |= LOAD_SOFT_BODY_ADD_BENDING_SPRINGS;
return 0;
}

2
examples/SharedMemory/PhysicsClientC_API.h
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@@ -643,7 +643,7 @@ extern "C"
B3_SHARED_API int b3LoadSoftBodySetSelfCollision(b3SharedMemoryCommandHandle commandHandle, int useSelfCollision);
B3_SHARED_API int b3LoadSoftBodyUseFaceContact(b3SharedMemoryCommandHandle commandHandle, int useFaceContact);
B3_SHARED_API int b3LoadSoftBodySetFrictionCoefficient(b3SharedMemoryCommandHandle commandHandle, double frictionCoefficient);
B3_SHARED_API int b3LoadSoftBodyUseBendingSprings(b3SharedMemoryCommandHandle commandHandle, int useBendingSprings);
B3_SHARED_API int b3LoadSoftBodyUseBendingSprings(b3SharedMemoryCommandHandle commandHandle, int useBendingSprings, double bendingStiffness);
B3_SHARED_API b3SharedMemoryCommandHandle b3InitCreateSoftBodyAnchorConstraintCommand(b3PhysicsClientHandle physClient, int softBodyUniqueId, int nodeIndex, int bodyUniqueId, int linkIndex, const double bodyFramePosition[3]);

33
examples/SharedMemory/PhysicsServerCommandProcessor.cpp
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@@ -8069,7 +8069,7 @@ bool PhysicsServerCommandProcessor::processLoadSoftBodyCommand(const struct Shar
{
collisionMargin = clientCmd.m_loadSoftBodyArguments.m_collisionMargin;
}
btScalar spring_bending_stiffness = 0;
{
btSoftBody* psb = NULL;
@@ -8136,7 +8136,7 @@ bool PhysicsServerCommandProcessor::processLoadSoftBodyCommand(const struct Shar
}
}
#ifndef SKIP_DEFORMABLE_BODY
btScalar spring_elastic_stiffness, spring_damping_stiffness;
btScalar spring_elastic_stiffness, spring_damping_stiffness;
if (clientCmd.m_updateFlags & LOAD_SOFT_BODY_ADD_MASS_SPRING_FORCE)
{
btDeformableMultiBodyDynamicsWorld* deformWorld = getDeformableWorld();
@@ -8144,7 +8144,11 @@ bool PhysicsServerCommandProcessor::processLoadSoftBodyCommand(const struct Shar
{
spring_elastic_stiffness = clientCmd.m_loadSoftBodyArguments.m_springElasticStiffness;
spring_damping_stiffness = clientCmd.m_loadSoftBodyArguments.m_springDampingStiffness;
btDeformableLagrangianForce* springForce = new btDeformableMassSpringForce(spring_elastic_stiffness, spring_damping_stiffness, false);
if (clientCmd.m_updateFlags & LOAD_SOFT_BODY_ADD_BENDING_SPRINGS)
{
spring_bending_stiffness = clientCmd.m_loadSoftBodyArguments.m_springBendingStiffness;
}
btDeformableLagrangianForce* springForce = new btDeformableMassSpringForce(spring_elastic_stiffness, spring_damping_stiffness, false, spring_bending_stiffness);
deformWorld->addForce(psb, springForce);
m_data->m_lf.push_back(springForce);
}
@@ -8177,12 +8181,16 @@ bool PhysicsServerCommandProcessor::processLoadSoftBodyCommand(const struct Shar
deformWorld->addForce(psb, neohookeanForce);
m_data->m_lf.push_back(neohookeanForce);
}
btScalar spring_elastic_stiffness, spring_damping_stiffness;
btScalar spring_elastic_stiffness, spring_damping_stiffness;
if (clientCmd.m_updateFlags & LOAD_SOFT_BODY_ADD_MASS_SPRING_FORCE)
{
spring_elastic_stiffness = clientCmd.m_loadSoftBodyArguments.m_springElasticStiffness;
spring_damping_stiffness = clientCmd.m_loadSoftBodyArguments.m_springDampingStiffness;
btDeformableLagrangianForce* springForce = new btDeformableMassSpringForce(spring_elastic_stiffness, spring_damping_stiffness, true);
if (clientCmd.m_updateFlags & LOAD_SOFT_BODY_ADD_BENDING_SPRINGS)
{
spring_bending_stiffness = clientCmd.m_loadSoftBodyArguments.m_springBendingStiffness;
}
btDeformableLagrangianForce* springForce = new btDeformableMassSpringForce(spring_elastic_stiffness, spring_damping_stiffness, true, spring_bending_stiffness);
deformWorld->addForce(psb, springForce);
m_data->m_lf.push_back(springForce);
}
@@ -8257,19 +8265,18 @@ bool PhysicsServerCommandProcessor::processLoadSoftBodyCommand(const struct Shar
friction_coeff = loadSoftBodyArgs.m_frictionCoeff;
}
psb->m_cfg.kDF = friction_coeff;
bool use_bending_spring = true;
bool use_bending_spring = false;
if (clientCmd.m_updateFlags & LOAD_SOFT_BODY_ADD_BENDING_SPRINGS)
{
use_bending_spring = loadSoftBodyArgs.m_useBendingSprings;
use_bending_spring = loadSoftBodyArgs.m_useBendingSprings;
if (use_bending_spring)
{
psb->generateBendingConstraints(2);
}
}
btSoftBody::Material* pm = psb->appendMaterial();
pm->m_flags -= btSoftBody::fMaterial::DebugDraw;
if (use_bending_spring)
{
psb->generateBendingConstraints(2,pm);
}
// turn on the collision flag for deformable
// collision between deformable and rigid
psb->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;

25
examples/SharedMemory/SharedMemoryCommands.h
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@@ -523,18 +523,19 @@ struct LoadSoftBodyArgs
double m_mass;
double m_collisionMargin;
double m_initialPosition[3];
double m_initialOrientation[4];
double m_springElasticStiffness;
double m_springDampingStiffness;
double m_corotatedMu;
double m_corotatedLambda;
int m_useBendingSprings;
double m_collisionHardness;
double m_useSelfCollision;
double m_frictionCoeff;
double m_NeoHookeanMu;
double m_NeoHookeanLambda;
double m_NeoHookeanDamping;
double m_initialOrientation[4];
double m_springElasticStiffness;
double m_springDampingStiffness;
double m_springBendingStiffness;
double m_corotatedMu;
double m_corotatedLambda;
int m_useBendingSprings;
double m_collisionHardness;
double m_useSelfCollision;
double m_frictionCoeff;
double m_NeoHookeanMu;
double m_NeoHookeanLambda;
double m_NeoHookeanDamping;
int m_useFaceContact;
char m_simFileName[MAX_FILENAME_LENGTH];
};

4
examples/SharedMemory/SharedMemoryPublic.h
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@@ -7,8 +7,8 @@
//Please don't replace an existing magic number:
//instead, only ADD a new one at the top, comment-out previous one
#define SHARED_MEMORY_MAGIC_NUMBER 201911180
#define SHARED_MEMORY_MAGIC_NUMBER 201911280
//#define SHARED_MEMORY_MAGIC_NUMBER 201911180
//#define SHARED_MEMORY_MAGIC_NUMBER 201909030
//#define SHARED_MEMORY_MAGIC_NUMBER 201908110
//#define SHARED_MEMORY_MAGIC_NUMBER 201908050

7
examples/pybullet/pybullet.c
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@@ -1973,7 +1973,7 @@ static PyObject* pybullet_loadSoftBody(PyObject* self, PyObject* args, PyObject*
int physicsClientId = 0;
int flags = 0;
static char* kwlist[] = {"fileName", "basePosition", "baseOrientation", "scale", "mass", "collisionMargin", "physicsClientId", "useMassSpring", "useBendingSprings", "useNeoHookean", "springElasticStiffness", "springDampingStiffness", "NeoHookeanMu", "NeoHookeanLambda", "NeoHookeanDamping", "frictionCoeff", "useFaceContact", "useSelfCollision", NULL};
static char* kwlist[] = {"fileName", "basePosition", "baseOrientation", "scale", "mass", "collisionMargin", "physicsClientId", "useMassSpring", "useBendingSprings", "useNeoHookean", "springElasticStiffness", "springDampingStiffness", "springBendingStiffness", "NeoHookeanMu", "NeoHookeanLambda", "NeoHookeanDamping", "frictionCoeff", "useFaceContact", "useSelfCollision", NULL};
int bodyUniqueId = -1;
const char* fileName = "";
@@ -1985,6 +1985,7 @@ static PyObject* pybullet_loadSoftBody(PyObject* self, PyObject* args, PyObject*
int useNeoHookean = 0;
double springElasticStiffness = 1;
double springDampingStiffness = 0.1;
double springBendingStiffness = 0.1;
double NeoHookeanMu = 1;
double NeoHookeanLambda = 1;
double NeoHookeanDamping = 0.1;
@@ -2002,7 +2003,7 @@ static PyObject* pybullet_loadSoftBody(PyObject* self, PyObject* args, PyObject*
PyObject* basePosObj = 0;
PyObject* baseOrnObj = 0;
if (!PyArg_ParseTupleAndKeywords(args, keywds, "s|OOdddiiiiddddddii", kwlist, &fileName, &basePosObj, &baseOrnObj, &scale, &mass, &collisionMargin, &physicsClientId, &useMassSpring, &useBendingSprings, &useNeoHookean, &springElasticStiffness, &springDampingStiffness, &NeoHookeanMu, &NeoHookeanLambda, &NeoHookeanDamping, &frictionCoeff, &useFaceContact, &useSelfCollision))
if (!PyArg_ParseTupleAndKeywords(args, keywds, "s|OOdddiiiidddddddii", kwlist, &fileName, &basePosObj, &baseOrnObj, &scale, &mass, &collisionMargin, &physicsClientId, &useMassSpring, &useBendingSprings, &useNeoHookean, &springElasticStiffness, &springDampingStiffness, &springBendingStiffness, &NeoHookeanMu, &NeoHookeanLambda, &NeoHookeanDamping, &frictionCoeff, &useFaceContact, &useSelfCollision))
{
return NULL;
}
@@ -2058,7 +2059,7 @@ static PyObject* pybullet_loadSoftBody(PyObject* self, PyObject* args, PyObject*
if (useMassSpring)
{
b3LoadSoftBodyAddMassSpringForce(command, springElasticStiffness, springDampingStiffness);
b3LoadSoftBodyUseBendingSprings(command, useBendingSprings);
b3LoadSoftBodyUseBendingSprings(command, useBendingSprings, springBendingStiffness);
}
if (useNeoHookean)
{