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/* -------------------------------------------------------------------------- *
* Simbody(tm) Example: Event Reporter *
* -------------------------------------------------------------------------- *
* This is part of the SimTK biosimulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org/home/simbody. *
* *
* Portions copyright (c) 2008-12 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Licensed under the Apache License, Version 2.0 (the "License"); you may *
* not use this file except in compliance with the License. You may obtain a *
* copy of the License at http://www.apache.org/licenses/LICENSE-2.0. *
* *
* Unless required by applicable law or agreed to in writing, software *
* distributed under the License is distributed on an "AS IS" BASIS, *
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. *
* See the License for the specific language governing permissions and *
* limitations under the License. *
* -------------------------------------------------------------------------- */
/* This example demonstrates the use of an event reporter to output some
interesting information during time stepping. The information is displayed
in the console (terminal) window, not the graphics window. */
#include "Simbody.h"
using namespace SimTK;
class PositionReporter : public PeriodicEventReporter {
public:
PositionReporter(const MultibodySystem& system, const MobilizedBody& body, Real interval) :
PeriodicEventReporter(interval), system(system), body(body) {
}
// Show x-y position of the pendulum weight as a function of time.
void handleEvent(const State& state) const override {
system.realize(state, Stage::Position);
Vec3 pos = body.getBodyOriginLocation(state);
std::cout<<state.getTime()<<"\t"<<pos[0]<<"\t"<<pos[1]<<std::endl;
}
private:
const MultibodySystem& system;
const MobilizedBody& body;
};
int main() {
// Create the system.
MultibodySystem system; system.setUseUniformBackground(true);
SimbodyMatterSubsystem matter(system);
GeneralForceSubsystem forces(system);
Force::UniformGravity gravity(forces, matter, Vec3(0, -9.8, 0));
Body::Rigid pendulumBody(MassProperties(1.0, Vec3(0), Inertia(1)));
pendulumBody.addDecoration(Transform(), DecorativeSphere(0.1));
MobilizedBody::Pin pendulum(matter.updGround(), Transform(Vec3(0)), pendulumBody, Transform(Vec3(0, 1, 0)));
Visualizer viz(system);
system.addEventReporter(new Visualizer::Reporter(viz, 1./30));
system.addEventReporter(new PositionReporter(system, pendulum, 0.1));
// Initialize the system and state.
system.realizeTopology();
State state = system.getDefaultState();
pendulum.setOneU(state, 0, 1.0);
// Simulate it.
RungeKuttaMersonIntegrator integ(system);
TimeStepper ts(system, integ);
ts.initialize(state);
ts.stepTo(100.0);
}
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