public float SolveLinearAxis(
float timeStep,
float jacDiagABInv,
RigidBody body1, ref Vector3 pointInA,
RigidBody body2, ref Vector3 pointInB,
int limit_index,
ref Vector3 axis_normal_on_a,
ref Vector3 anchorPos)
{
///find relative velocity
// Vector3 rel_pos1 = pointInA - body1.getCenterOfMassPosition();
// Vector3 rel_pos2 = pointInB - body2.getCenterOfMassPosition();
Vector3 rel_pos1 = anchorPos - body1.GetCenterOfMassPosition();
Vector3 rel_pos2 = anchorPos - body2.GetCenterOfMassPosition();
Vector3 vel1 = Vector3.Zero;
body1.InternalGetVelocityInLocalPointObsolete(ref rel_pos1,ref vel1);
Vector3 vel2 = Vector3.Zero;;
body2.InternalGetVelocityInLocalPointObsolete(ref rel_pos2,ref vel2);
Vector3 vel = vel1 - vel2;
float rel_vel = Vector3.Dot(axis_normal_on_a,vel);
/// apply displacement correction
//positional error (zeroth order error)
float depth = -Vector3.Dot((pointInA - pointInB),axis_normal_on_a);
float lo = float.MinValue;
float hi = float.MaxValue;
float minLimit = MathUtil.VectorComponent(ref m_lowerLimit,limit_index);
float maxLimit = MathUtil.VectorComponent(ref m_upperLimit,limit_index);
//handle the limits
if (minLimit < maxLimit)
{
{
if (depth > maxLimit)
{
depth -= maxLimit;
lo = 0f;
}
else
{
if (depth < minLimit)
{
depth -= minLimit;
hi = 0f;
}
else
{
return 0.0f;
}
}
}
}
float normalImpulse= m_limitSoftness*(m_restitution*depth/timeStep - m_damping*rel_vel) * jacDiagABInv;
float oldNormalImpulse = MathUtil.VectorComponent(ref m_accumulatedImpulse,limit_index);
float sum = oldNormalImpulse + normalImpulse;
MathUtil.VectorComponent(ref m_accumulatedImpulse,limit_index,(sum > hi ? 0f: sum < lo ? 0f : sum));
normalImpulse = MathUtil.VectorComponent(ref m_accumulatedImpulse,limit_index) - oldNormalImpulse;
Vector3 impulse_vector = axis_normal_on_a * normalImpulse;
//body1.applyImpulse( impulse_vector, rel_pos1);
//body2.applyImpulse(-impulse_vector, rel_pos2);
Vector3 ftorqueAxis1 = Vector3.Cross(rel_pos1,axis_normal_on_a);
Vector3 ftorqueAxis2 = Vector3.Cross(rel_pos2,axis_normal_on_a);
body1.InternalApplyImpulse(axis_normal_on_a*body1.GetInvMass(), Vector3.TransformNormal(ftorqueAxis1,body1.GetInvInertiaTensorWorld()),normalImpulse);
body2.InternalApplyImpulse(axis_normal_on_a * body2.GetInvMass(), Vector3.TransformNormal(ftorqueAxis2,body2.GetInvInertiaTensorWorld()), -normalImpulse);
return normalImpulse;
}
//! apply the correction impulses for two bodies
public float SolveAngularLimits(float timeStep,ref Vector3 axis, float jacDiagABInv,RigidBody body0, RigidBody body1)
{
if (NeedApplyTorques() == false)
{
return 0.0f;
}
float target_velocity = m_targetVelocity;
float maxMotorForce = m_maxMotorForce;
//current error correction
if (m_currentLimit!=0)
{
target_velocity = -m_stopERP*m_currentLimitError/(timeStep);
maxMotorForce = m_maxLimitForce;
}
maxMotorForce *= timeStep;
// current velocity difference
Vector3 angVelA = Vector3.Zero;
body0.InternalGetAngularVelocity(ref angVelA);
Vector3 angVelB = Vector3.Zero;
body1.InternalGetAngularVelocity(ref angVelB);
Vector3 vel_diff = angVelA-angVelB;
float rel_vel = Vector3.Dot(axis,vel_diff);
// correction velocity
float motor_relvel = m_limitSoftness*(target_velocity - m_damping*rel_vel);
if ( motor_relvel < MathUtil.SIMD_EPSILON && motor_relvel > -MathUtil.SIMD_EPSILON )
{
return 0.0f;//no need for applying force
}
// correction impulse
float unclippedMotorImpulse = (1+m_bounce)*motor_relvel*jacDiagABInv;
// clip correction impulse
float clippedMotorImpulse;
///@todo: should clip against accumulated impulse
if (unclippedMotorImpulse>0.0f)
{
clippedMotorImpulse = unclippedMotorImpulse > maxMotorForce? maxMotorForce: unclippedMotorImpulse;
}
else
{
clippedMotorImpulse = unclippedMotorImpulse < -maxMotorForce ? -maxMotorForce: unclippedMotorImpulse;
}
// sort with accumulated impulses
float lo = float.MinValue;
float hi = float.MaxValue;
float oldaccumImpulse = m_accumulatedImpulse;
float sum = oldaccumImpulse + clippedMotorImpulse;
m_accumulatedImpulse = sum > hi ? 0f : sum < lo ? 0f : sum;
clippedMotorImpulse = m_accumulatedImpulse - oldaccumImpulse;
Vector3 motorImp = clippedMotorImpulse * axis;
//body0.applyTorqueImpulse(motorImp);
//body1.applyTorqueImpulse(-motorImp);
body0.InternalApplyImpulse(Vector3.Zero, Vector3.TransformNormal(axis,body0.GetInvInertiaTensorWorld()),clippedMotorImpulse);
body1.InternalApplyImpulse(Vector3.Zero, Vector3.TransformNormal(axis,body1.GetInvInertiaTensorWorld()),-clippedMotorImpulse);
return clippedMotorImpulse;
}