int main() {
try
{ // Create the system.
MultibodySystem system;
SimbodyMatterSubsystem matter(system);
GeneralForceSubsystem forces(system);
Force::Gravity gravity(forces, matter, UnitVec3(-1,0,0), 9.81);
ContactTrackerSubsystem tracker(system);
CompliantContactSubsystem contactForces(system, tracker);
contactForces.setTrackDissipatedEnergy(true);
contactForces.setTransitionVelocity(1e-2); // m/s
// Ground's normal is +x for this model
system.setUpDirection(+XAxis);
// Uncomment this if you want a more elegant movie.
//matter.setShowDefaultGeometry(false);
const Real ud = .3; // dynamic
const Real us = .6; // static
const Real uv = 0; // viscous (force/velocity)
const Real k = 1e8; // pascals
const Real c = 0.01; // dissipation (1/v)
// Halfspace default is +x, this one occupies -x instead, so flip.
const Rotation R_xdown(Pi,ZAxis);
matter.Ground().updBody().addContactSurface(
Transform(R_xdown, Vec3(0,0,0)),
ContactSurface(ContactGeometry::HalfSpace(),
ContactMaterial(k,c,us,ud,uv)));
const Real ellipsoidMass = 1; // kg
const Vec3 halfDims(2*Cm2m, 20*Cm2m, 3*Cm2m); // m (read in cm)
const Vec3 comLoc(-1*Cm2m, 0, 0);
const Inertia centralInertia(Vec3(17,2,16)*CmSq2mSq, Vec3(0,0,.2)*CmSq2mSq); // now kg-m^2
const Inertia inertia(centralInertia.shiftFromMassCenter(-comLoc, ellipsoidMass)); // in S
Body::Rigid ellipsoidBody(MassProperties(ellipsoidMass, comLoc, inertia));
ellipsoidBody.addDecoration(Transform(),
DecorativeEllipsoid(halfDims).setColor(Cyan)
//.setOpacity(.5)
.setResolution(3));
ellipsoidBody.addContactSurface(Transform(),
ContactSurface(ContactGeometry::Ellipsoid(halfDims),
ContactMaterial(k,c,us,ud,uv))
);
MobilizedBody::Free ellipsoid(matter.Ground(), Transform(Vec3(0,0,0)),
ellipsoidBody, Transform(Vec3(0)));
Visualizer viz(system);
viz.addDecorationGenerator(new ForceArrowGenerator(system,contactForces));
viz.setMode(Visualizer::RealTime);
viz.setDesiredFrameRate(FrameRate);
viz.setCameraClippingPlanes(0.1, 10);
Visualizer::InputSilo* silo = new Visualizer::InputSilo();
viz.addInputListener(silo);
Array_<std::pair<String,int> > runMenuItems;
runMenuItems.push_back(std::make_pair("Go", GoItem));
runMenuItems.push_back(std::make_pair("Replay", ReplayItem));
runMenuItems.push_back(std::make_pair("Quit", QuitItem));
viz.addMenu("Run", RunMenuId, runMenuItems);
Array_<std::pair<String,int> > helpMenuItems;
helpMenuItems.push_back(std::make_pair("TBD - Sorry!", 1));
viz.addMenu("Help", HelpMenuId, helpMenuItems);
system.addEventReporter(new MyReporter(system,contactForces,ReportInterval));
system.addEventReporter(new Visualizer::Reporter(viz, ReportInterval));
// Check for a Run->Quit menu pick every 1/4 second.
system.addEventHandler(new UserInputHandler(*silo, .25));
// Initialize the system and state.
system.realizeTopology();
State state = system.getDefaultState();
matter.setUseEulerAngles(state, true);
system.realizeModel(state);
ellipsoid.setQToFitTransform(state, Transform(
Rotation(BodyRotationSequence, 0 *Deg2Rad, XAxis,
0.5*Deg2Rad, YAxis,
-0.5*Deg2Rad, ZAxis),
Vec3(2.1*Cm2m, 0, 0)));
ellipsoid.setUToFitAngularVelocity(state, 2*Vec3(5,0,0)); // rad/s
viz.report(state);
printf("Default state\n");
cout << "\nChoose 'Go' from Run menu to simulate:\n";
int menuId, item;
do { silo->waitForMenuPick(menuId, item);
if (menuId != RunMenuId || item != GoItem)
cout << "\aDude ... follow instructions!\n";
} while (menuId != RunMenuId || item != GoItem);
// Simulate it.
//ExplicitEulerIntegrator integ(system);
//CPodesIntegrator integ(system,CPodes::BDF,CPodes::Newton);
//RungeKuttaFeldbergIntegrator integ(system);
RungeKuttaMersonIntegrator integ(system);
//RungeKutta3Integrator integ(system);
//VerletIntegrator integ(system);
//integ.setMaximumStepSize(1e-0001);
integ.setAccuracy(1e-4); // minimum for CPodes
//integ.setAccuracy(.01);
TimeStepper ts(system, integ);
ts.initialize(state);
double cpuStart = cpuTime();
double realStart = realTime();
ts.stepTo(10.0);
const double timeInSec = realTime() - realStart;
const int evals = integ.getNumRealizations();
cout << "Done -- took " << integ.getNumStepsTaken() << " steps in " <<
timeInSec << "s elapsed for " << ts.getTime() << "s sim (avg step="
<< (1000*ts.getTime())/integ.getNumStepsTaken() << "ms) "
<< (1000*ts.getTime())/evals << "ms/eval\n";
cout << " CPU time was " << cpuTime() - cpuStart << "s\n";
printf("Using Integrator %s at accuracy %g:\n",
integ.getMethodName(), integ.getAccuracyInUse());
printf("# STEPS/ATTEMPTS = %d/%d\n", integ.getNumStepsTaken(), integ.getNumStepsAttempted());
printf("# ERR TEST FAILS = %d\n", integ.getNumErrorTestFailures());
printf("# REALIZE/PROJECT = %d/%d\n", integ.getNumRealizations(), integ.getNumProjections());
viz.dumpStats(std::cout);
// Add as slider to control playback speed.
viz.addSlider("Speed", 1, 0, 4, 1);
viz.setMode(Visualizer::PassThrough);
silo->clear(); // forget earlier input
double speed = 1; // will change if slider moves
while(true) {
cout << "Choose Run/Replay to see that again ...\n";
int menuId, item;
silo->waitForMenuPick(menuId, item);
if (menuId != RunMenuId) {
cout << "\aUse the Run menu!\n";
continue;
}
if (item == QuitItem)
break;
if (item != ReplayItem) {
cout << "\aHuh? Try again.\n";
continue;
}
for (double i=0; i < (int)saveEm.size(); i += speed ) {
int slider; Real newValue;
if (silo->takeSliderMove(slider,newValue)) {
speed = newValue;
}
viz.report(saveEm[(int)i]);
}
}
} catch (const std::exception& e) {
std::printf("EXCEPTION THROWN: %s\n", e.what());
exit(1);
} catch (...) {
std::printf("UNKNOWN EXCEPTION THROWN\n");
exit(1);
}
return 0;
}
