/**
* @brief Create the physical model
*
* @param m Mass of the particle
* @param s Stiffness of the spring
* @param d Damping ratio of the spring
* @param xx0 initial position
* @param vv0 initial velocity
*/
void setup(
SReal m, SReal s, SReal d,
SReal xx0, SReal vv0
)
{
mass = m;
stiffness = s;
damping = d;
x0=xx0; v0=vv0;
node = clearScene();
node->setGravity( Vec3(0,0,0) );
// The oscillator
simulation::Node::SPtr oscillator = node->createChild("oscillator");
DOF = addNew<MechanicalObject1>(oscillator,"DOF");
DOF->resize(1);
DOF->writePositions()[0] = Vec1(x0);
DOF->writeVelocities()[0] = Vec1(v0);
UniformMass1::SPtr Mass = addNew<UniformMass1>(oscillator,"mass");
Mass->mass.setValue( mass );
compliance = addNew<UniformCompliance1>(oscillator,"compliance");
compliance->isCompliance.setValue(false);
compliance->compliance.setValue(1.0/stiffness);
compliance->damping.setValue(damping);
}
/// Create the context for the scene
void createScene(double K, double m, double l0, double rm=0, double rk=0)
{
// Init simulation
sofa::simulation::setSimulation(simulation = new sofa::simulation::graph::DAGSimulation());
root = simulation::getSimulation()->createNewGraph("root");
// Create the scene
root->setGravity(Coord(0,-10,0));
// Solver
variationalSolver = addNew<VariationalSymplecticSolver> (getRoot());
variationalSolver->f_rayleighStiffness.setValue(rk);
variationalSolver->f_rayleighMass.setValue(rm);
variationalSolver->f_computeHamiltonian.setValue(1);
variationalSolver->f_newtonError.setValue(1e-12);//1e-18
variationalSolver->f_newtonSteps.setValue(4);//7
CGLinearSolver::SPtr cgLinearSolver = addNew<CGLinearSolver> (getRoot());
cgLinearSolver->f_maxIter=3000;
cgLinearSolver->f_tolerance =1e-12;
cgLinearSolver->f_smallDenominatorThreshold=1e-12;
// Set initial positions and velocities of fixed point and mass
MechanicalObject3::VecCoord xFixed(1);
MechanicalObject3::DataTypes::set( xFixed[0], 0., 2.,0.);
MechanicalObject3::VecDeriv vFixed(1);
MechanicalObject3::DataTypes::set( vFixed[0], 0.,0.,0.);
MechanicalObject3::VecCoord xMass(1);
MechanicalObject3::DataTypes::set( xMass[0], 0., 1.,0.);
MechanicalObject3::VecDeriv vMass(1);
MechanicalObject3::DataTypes::set( vMass[0], 0., 0., 0.);
// Mass spring system
root = this-> createMassSpringSystem(
root, // add mass spring system to the node containing solver
K, // stiffness
m, // mass
l0, // spring rest length
xFixed, // Initial position of fixed point
vFixed, // Initial velocity of fixed point
xMass, // Initial position of mass
vMass); // Initial velocity of mass
}