Bart/bullet3
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

separate in-plane and bending stiffness for mass spring model for easier parameter tuning

Browse Source
This commit is contained in:
Xuchen Han
2019-11-27 11:40:10 -08:00
parent 574343405d
commit 7bce5d61f4
6 changed files with 50 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
examples/SharedMemory/PhysicsClientC_API.cpp
View File

@@ -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
View File

@@ -643,7 +643,7 @@ extern "C"
B3_SHARED_API int b3LoadSoftBodyUseSelfCollision(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
View File

@@ -8070,7 +8070,7 @@ bool PhysicsServerCommandProcessor::processLoadSoftBodyCommand(const struct Shar
{
collisionMargin = clientCmd.m_loadSoftBodyArguments.m_collisionMargin;
}
btScalar spring_bending_stiffness = 0;
{
btSoftBody* psb = NULL;
@@ -8137,7 +8137,7 @@ 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();
@@ -8145,7 +8145,11 @@ 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);
}
@@ -8178,12 +8182,16 @@ 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);
}
@@ -8258,19 +8266,18 @@ 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
View File

@@ -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];
};