public ChainSim(Game game, GameModel[] ropeSegmentModels, float totalMass, float stiffness, float damping)
: base(game)
{
//create sim data
float sphereMass = totalMass / ropeSegmentModels.Length;
SimModel[] simObjs = new SimModel[ropeSegmentModels.Length];
for (int i = 0; i < ropeSegmentModels.Length; i++)
{
simObjs[i] = new SimModel(ropeSegmentModels[i], sphereMass, SimObjectType.ACTIVE);
this.AddSimObject(simObjs[i]);
}
//attach springs between the sim objects
for (int i = 1; i < ropeSegmentModels.Length; i++)
{
this.AddSpring(stiffness, damping, simObjs[i - 1], simObjs[i]);
this.Constraints.Add(new LengthConstraint((simObjs[i - 1].Model.Translate - simObjs[i].Model.Translate).Length(), simObjs[i - 1], simObjs[i]));
}
}
private void InitSpringScene()
{
//load in a cube and a sphere
GameModel stationaryCube = modelComponent.LoadGameModel(@"cube");
stationaryCube.TranslateY = 5;
GameModel movingSphere = modelComponent.LoadGameModel(@"sphere");
//create a spring sim
springSim = new Simulation(this);
//create sim objects from the loaded models
float sphereMass = 1.0f;
movingSphereSimObj = new SimModel(movingSphere, sphereMass, SimObjectType.ACTIVE);
springSim.AddSimObject(movingSphereSimObj);
stationaryCubeSimObj = new SimModel(stationaryCube, 1000.0f, SimObjectType.PASSIVE);
springSim.AddSimObject(stationaryCubeSimObj);
//add in a global force generator: gravity
Gravity gravity = new Gravity(new Vector3(0, -9.81f, 0));
springSim.AddGlobalForceGenerator(gravity);
//add in a global force generator: air
float dragCoefficient = 0.5f;
Medium air = new Medium(dragCoefficient);
springSim.AddGlobalForceGenerator(air);
//attach a spring between the sim objects
float stiffness = 8.0f;
float damping = 0.1f;
springSim.AddSpring(stiffness, damping, stationaryCubeSimObj, movingSphereSimObj);
//create an integrator and assign it to the sim
ForwardEulerIntegrator integrator = new ForwardEulerIntegrator(this);
springSim.Integrator = integrator;
//init the line from cube to sphere that represents the spring
line3DComponent.StartPosition = stationaryCube.Translate;
line3DComponent.EndPosition = movingSphere.Translate;
line3DComponent.Color = Color.White;
}
