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Code Issues Releases Wiki Activity

reduced dofs and interpolated transform needs to be updated from the time_n states in the iteration

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This commit is contained in:
jingyuc 2021-08-09 12:43:59 -04:00
parent 0acf18f246
commit a56ce358f3
4 changed files with 26 additions and 17 deletions
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6
examples/ReducedDeformableDemo/BasicTest.cpp
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@ -106,8 +106,8 @@ public:
// // rsb->mapToReducedDofs();
// }
// float internalTimeStep = 1. / 60.f;
float internalTimeStep = 1e-3;
float internalTimeStep = 1. / 60.f;
// float internalTimeStep = 1e-3;
m_dynamicsWorld->stepSimulation(deltaTime, 1, internalTimeStep);
}
@ -185,7 +185,7 @@ void BasicTest::initPhysics()
// rsb->scale(btVector3(1, 1, 1));
rsb->translate(btVector3(0, 4, 0)); //TODO: add back translate and scale
// rsb->setTotalMass(0.5);
rsb->setStiffnessScale(100);
rsb->setStiffnessScale(0.5);
rsb->setFixedNodes();
rsb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
rsb->m_cfg.kCHR = 1; // collision hardness with rigid body

34
src/BulletSoftBody/BulletReducedSoftBody/btReducedSoftBody.cpp
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@ -40,6 +40,7 @@ void btReducedSoftBody::setReducedModes(int start_mode, int num_modes, int full_
m_nReduced = num_modes;
m_nFull = full_size;
m_reducedDofs.resize(m_nReduced, 0);
m_reducedDofsBuffer.resize(m_nReduced, 0);
m_reducedVelocity.resize(m_nReduced, 0);
m_reducedForceInternal.resize(m_nReduced, 0);
m_reducedForceExternal.resize(m_nReduced, 0);
@ -97,6 +98,7 @@ void btReducedSoftBody::setInertiaProps(const btVector3& inertia)
// update world inertia tensor
updateInertiaTensor();
m_interpolateInvInertiaTensorWorld = m_invInertiaTensorWorld;
}
void btReducedSoftBody::setRigidVelocity(const btVector3& v)
@ -127,9 +129,9 @@ void btReducedSoftBody::setFixedNodes()
// m_fixedNodes.push_back(i);
// }
m_fixedNodes.push_back(0);
// m_fixedNodes.push_back(1);
// m_fixedNodes.push_back(2);
// m_fixedNodes.push_back(3);
m_fixedNodes.push_back(1);
m_fixedNodes.push_back(2);
m_fixedNodes.push_back(3);
// m_fixedNodes.push_back(15);
// m_fixedNodes.push_back(18);
@ -228,6 +230,7 @@ void btReducedSoftBody::endOfTimeStepZeroing()
{
m_reducedForceInternal[i] = 0;
m_reducedForceExternal[i] = 0;
m_reducedDofsBuffer[i] = m_reducedDofs[i];
}
std::cout << "zeroed!\n";
}
@ -241,7 +244,7 @@ void btReducedSoftBody::updateReducedDofs(btScalar solverdt)
{
for (int r = 0; r < m_nReduced; ++r)
{
m_reducedDofs[r] += solverdt * m_reducedVelocity[r];
m_reducedDofs[r] = m_reducedDofsBuffer[r] + solverdt * m_reducedVelocity[r];
}
}
@ -300,11 +303,13 @@ void btReducedSoftBody::proceedToTransform(btScalar dt, bool end_of_time_step)
if (end_of_time_step)
{
m_rigidTransformWorld = m_interpolationWorldTransform;
updateInertiaTensor();
// updateInertiaTensor();
m_invInertiaTensorWorld = m_interpolateInvInertiaTensorWorld;
}
else
{
btTransformUtil::integrateTransform(m_interpolationWorldTransform, m_linearVelocity, m_angularVelocity, dt, m_interpolationWorldTransform);
btTransformUtil::integrateTransform(m_rigidTransformWorld, m_linearVelocity, m_angularVelocity, dt, m_interpolationWorldTransform);
m_interpolateInvInertiaTensorWorld = m_interpolationWorldTransform.getBasis().scaled(m_invInertiaLocal) * m_interpolationWorldTransform.getBasis().transpose();
}
// m_interpolationLinearVelocity = getLinearVelocity(); // TODO: check where these are used?
// m_interpolationAngularVelocity = getAngularVelocity();
@ -352,7 +357,7 @@ void btReducedSoftBody::applyCentralImpulse(const btVector3& impulse)
void btReducedSoftBody::applyTorqueImpulse(const btVector3& torque)
{
m_angularVelocity += m_invInertiaTensorWorld * torque * m_angularFactor;
m_angularVelocity += m_interpolateInvInertiaTensorWorld * torque * m_angularFactor;
#if defined(BT_CLAMP_VELOCITY_TO) && BT_CLAMP_VELOCITY_TO > 0
clampVelocity(m_angularVelocity);
#endif
@ -381,7 +386,6 @@ void btReducedSoftBody::applyVelocityConstraint(const btVector3& target_vel, int
// rigid part
btScalar inv_mass = m_nodalMass[n_node] > btScalar(0) ? btScalar(1) / m_mass : btScalar(0);
btMatrix3x3 K1 = Diagonal(inv_mass);
btMatrix3x3 m_interpolateInvInertiaTensorWorld = m_interpolationWorldTransform.getBasis().scaled(m_invInertiaLocal) * m_interpolationWorldTransform.getBasis().transpose();
K1 -= ri_skew * m_interpolateInvInertiaTensorWorld * ri_skew;
// reduced deformable part
@ -446,9 +450,9 @@ void btReducedSoftBody::applyVelocityConstraint(const btVector3& target_vel, int
impulse_magnitude = 0;
}
std::ofstream myfile("impulse_"+std::to_string(counter)+".txt", std::ios_base::app);
myfile << impulse_magnitude << '\n';
myfile.close();
// std::ofstream myfile("impulse_"+std::to_string(counter)+".txt", std::ios_base::app);
// myfile << impulse_magnitude << '\n';
// myfile.close();
// apply full space impulse
applyFullSpaceImpulse(impulse, ri, n_node, dt);
@ -482,6 +486,8 @@ void btReducedSoftBody::applyFullSpaceImpulse(const btVector3& impulse, const bt
// impulse causes rigid motion
applyRigidImpulse(impulse, rel_pos);
std::cout << "linear_v: " << m_linearVelocity[0] << '\t' << m_linearVelocity[1] << '\t' << m_linearVelocity[2] << '\n';
std::cout << "angular_v: " << m_angularVelocity[0] << '\t' << m_angularVelocity[1] << '\t' << m_angularVelocity[2] << '\n';
}
void btReducedSoftBody::applyFullSpaceNodalForce(const btVector3& f_ext, int n_node)
@ -537,7 +543,7 @@ void btReducedSoftBody::applyReducedInternalForce(const btScalar damping_alpha,
void btReducedSoftBody::applyFixedContraints(btScalar dt)
{
for (int iter = 0; iter < 200; ++iter)
for (int iter = 0; iter < 100; ++iter)
{
// std::cout << "iteration: " << iter << '\n';
// btVector3 vel_error(0, 0, 0);
@ -569,7 +575,7 @@ void btReducedSoftBody::applyFixedContraints(btScalar dt)
// }
}
// std::cin.get();
if (counter == 2)
exit(1);
// if (counter == 8)
// exit(1);
counter++;
}

2
src/BulletSoftBody/BulletReducedSoftBody/btReducedSoftBody.h
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@ -46,6 +46,7 @@ class btReducedSoftBody : public btSoftBody
btVector3 m_invInertiaLocal;
btTransform m_rigidTransformWorld;
btMatrix3x3 m_invInertiaTensorWorld;
btMatrix3x3 m_interpolateInvInertiaTensorWorld;
btVector3 m_initialOrigin; // initial center of mass (original of the m_rigidTransformWorld)
public:
@ -62,6 +63,7 @@ class btReducedSoftBody : public btSoftBody
int m_nFull;
tDenseMatrix m_modes; // modes of the reduced deformable model. Each inner array is a mode, outer array size = n_modes
tDenseArray m_reducedDofs; // Reduced degree of freedom
tDenseArray m_reducedDofsBuffer; // Reduced degree of freedom at t^n
tDenseArray m_reducedVelocity; // Reduced velocity array
tDenseArray m_reducedForceExternal; // reduced external force
tDenseArray m_reducedForceInternal; // reduced internal force

1
src/BulletSoftBody/CMakeLists.txt
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@ -28,6 +28,7 @@ SET(BulletSoftBody_SRCS
BulletReducedSoftBody/btReducedSoftBody.cpp
BulletReducedSoftBody/btReducedSoftBodyHelpers.cpp
BulletReducedSoftBody/btReducedSoftBodySolver.cpp
# BulletReducedSoftBody/
)