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dgregorius: Fixed joint improvements - consideration of zeroth order term

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dondickied
2006-06-17 10:59:50 +00:00
parent f348d28972
commit 2cf71b51a7
1 changed files with 31 additions and 18 deletions
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49
BulletDynamics/ConstraintSolver/Generic6DofConstraint.cpp
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@@ -19,6 +19,9 @@ subject to the following restrictions:
#include "Dynamics/MassProps.h" #include "Dynamics/MassProps.h"
#include "SimdTransformUtil.h" #include "SimdTransformUtil.h"
static const SimdScalar kSign[] = { 1.0f, -1.0f, 1.0f };
static const int kAxisA[] = { 1, 0, 0 };
static const int kAxisB[] = { 2, 2, 1 };
Generic6DofConstraint::Generic6DofConstraint() Generic6DofConstraint::Generic6DofConstraint()
{ {
@@ -62,18 +65,36 @@ void Generic6DofConstraint::BuildJacobian()
// angular part // angular part
for (int i=0;i<3;i++) for (int i=0;i<3;i++)
{ {
#if 0
SimdVector3 axisInA = m_frameInA.getBasis().getColumn(i); SimdVector3 axisInA = m_frameInA.getBasis().getColumn(i);
SimdVector3 axisInB = m_frameInB.getBasis().getColumn(i); SimdVector3 axisInB = m_frameInB.getBasis().getColumn(i);
new (&m_jacAng[i]) JacobianEntry(axisInA, axisInB, new (&m_jacAng[i]) JacobianEntry(axisInA, axisInB,
m_rbA.getInvInertiaDiagLocal(), m_rbA.getInvInertiaDiagLocal(),
m_rbB.getInvInertiaDiagLocal()); m_rbB.getInvInertiaDiagLocal());
#else
SimdVector3 axisA = m_rbA.getCenterOfMassTransform().getBasis() * m_frameInA.getBasis().getColumn( kAxisA[i] );
SimdVector3 axisB = m_rbB.getCenterOfMassTransform().getBasis() * m_frameInB.getBasis().getColumn( kAxisB[i] );
SimdVector3 axis = kSign[i] * axisA.cross(axisB);
new (&m_jacAng[i]) JacobianEntry(axis,
m_rbA.getCenterOfMassTransform().getBasis().transpose(),
m_rbB.getCenterOfMassTransform().getBasis().transpose(),
m_rbA.getInvInertiaDiagLocal(),
m_rbB.getInvInertiaDiagLocal());
#endif
} }
} }
void Generic6DofConstraint::SolveConstraint(SimdScalar timeStep) void Generic6DofConstraint::SolveConstraint(SimdScalar timeStep)
{ {
SimdScalar tau = 0.0f; SimdScalar tau = 0.1f;
SimdScalar damping = 1.0f; SimdScalar damping = 1.0f;
SimdVector3 pivotAInW = m_rbA.getCenterOfMassTransform() * m_frameInA.getOrigin(); SimdVector3 pivotAInW = m_rbA.getCenterOfMassTransform() * m_frameInA.getOrigin();
@@ -81,23 +102,15 @@ void Generic6DofConstraint::SolveConstraint(SimdScalar timeStep)
SimdVector3 rel_pos1 = pivotAInW - m_rbA.getCenterOfMassPosition(); SimdVector3 rel_pos1 = pivotAInW - m_rbA.getCenterOfMassPosition();
SimdVector3 rel_pos2 = pivotBInW - m_rbB.getCenterOfMassPosition(); SimdVector3 rel_pos2 = pivotBInW - m_rbB.getCenterOfMassPosition();
//#define JACOBIAN_STYLE
#ifdef JACOBIAN_STYLE
SimdVector3 angvelA = m_rbA.getCenterOfMassTransform().getBasis().transpose() * m_rbA.getAngularVelocity();
SimdVector3 angvelB = m_rbB.getCenterOfMassTransform().getBasis().transpose() * m_rbB.getAngularVelocity();
#endif
SimdVector3 normal(0,0,0); SimdVector3 normal(0,0,0);
// linear // linear
for (int i=0;i<3;i++) for (int i=0;i<3;i++)
{ {
#ifndef JACOBIAN_STYLE
SimdVector3 angvelA = m_rbA.getCenterOfMassTransform().getBasis().transpose() * m_rbA.getAngularVelocity(); SimdVector3 angvelA = m_rbA.getCenterOfMassTransform().getBasis().transpose() * m_rbA.getAngularVelocity();
SimdVector3 angvelB = m_rbB.getCenterOfMassTransform().getBasis().transpose() * m_rbB.getAngularVelocity(); SimdVector3 angvelB = m_rbB.getCenterOfMassTransform().getBasis().transpose() * m_rbB.getAngularVelocity();
#endif
normal[i] = 1; normal[i] = 1;
SimdScalar jacDiagABInv = 1.f / m_jac[i].getDiagonal(); SimdScalar jacDiagABInv = 1.f / m_jac[i].getDiagonal();
@@ -121,11 +134,9 @@ void Generic6DofConstraint::SolveConstraint(SimdScalar timeStep)
// angular // angular
for (int i=0;i<3;i++) for (int i=0;i<3;i++)
{ {
#ifndef JACOBIAN_STYLE
SimdVector3 angvelA = m_rbA.getCenterOfMassTransform().getBasis().transpose() * m_rbA.getAngularVelocity(); SimdVector3 angvelA = m_rbA.getCenterOfMassTransform().getBasis().transpose() * m_rbA.getAngularVelocity();
SimdVector3 angvelB = m_rbB.getCenterOfMassTransform().getBasis().transpose() * m_rbB.getAngularVelocity(); SimdVector3 angvelB = m_rbB.getCenterOfMassTransform().getBasis().transpose() * m_rbB.getAngularVelocity();
#endif
SimdScalar jacDiagABInv = 1.f / m_jacAng[i].getDiagonal(); SimdScalar jacDiagABInv = 1.f / m_jacAng[i].getDiagonal();
//velocity error (first order error) //velocity error (first order error)
@@ -133,14 +144,16 @@ void Generic6DofConstraint::SolveConstraint(SimdScalar timeStep)
m_rbB.getLinearVelocity(),angvelB); m_rbB.getLinearVelocity(),angvelB);
//positional error (zeroth order error) //positional error (zeroth order error)
SimdVector3 axisA = m_rbA.getCenterOfMassTransform().getBasis() * m_frameInA.getBasis().getColumn(i); SimdVector3 axisA = m_rbA.getCenterOfMassTransform().getBasis() * m_frameInA.getBasis().getColumn( kAxisA[i] );
SimdVector3 axisB = m_rbB.getCenterOfMassTransform().getBasis() * m_frameInB.getBasis().getColumn(i); SimdVector3 axisB = m_rbB.getCenterOfMassTransform().getBasis() * m_frameInB.getBasis().getColumn( kAxisB[i] );
SimdScalar rel_pos = 0.0f * axisB.dot(axisA); SimdScalar rel_pos = kSign[i] * axisA.dot(axisB);
//impulse //impulse
SimdScalar impulse = (tau*rel_pos/timeStep - damping*rel_vel) * jacDiagABInv; SimdScalar impulse = -(tau*rel_pos/timeStep + damping*rel_vel) * jacDiagABInv;
SimdVector3 impulse_vector = axisA * impulse;
SimdVector3 axis = kSign[i] * axisA.cross(axisB).normalized();
SimdVector3 impulse_vector = axis * impulse;
m_rbA.applyTorqueImpulse( impulse_vector); m_rbA.applyTorqueImpulse( impulse_vector);
m_rbB.applyTorqueImpulse(-impulse_vector); m_rbB.applyTorqueImpulse(-impulse_vector);