public RollingSphereSample(Microsoft.Xna.Framework.Game game)
: base(game)
{
// To demonstrate the problems with triangle meshes we increase the gravity and let a
// sphere roll over a curved surface.
// Add basic force effects.
Simulation.ForceEffects.Add(new Gravity { Acceleration = new Vector3F(0, -30, 0) }); // Higher gravity to make the problem more visible.
Simulation.ForceEffects.Add(new Damping());
// Use the custom contact filter to improve sphere contacts.
_sphereContactFilter = new SphereContactFilter();
Simulation.CollisionDomain.CollisionDetection.ContactFilter = _sphereContactFilter;
// The triangle mesh could be loaded from a file, such as an XNA Model.
// In this example will create a height field and convert the height field into a triangle mesh.
var numberOfSamplesX = 60;
var numberOfSamplesZ = 10;
var samples = new float[numberOfSamplesX * numberOfSamplesZ];
for (int z = 0; z < numberOfSamplesZ; z++)
for (int x = 0; x < numberOfSamplesX; x++)
samples[z * numberOfSamplesX + x] = (float)(Math.Sin(x / 6f) * 10f + 5f);
var heightField = new HeightField(0, 0, 70, 30, samples, numberOfSamplesX, numberOfSamplesZ);
// Convert the height field to a triangle mesh.
ITriangleMesh mesh = heightField.GetMesh(0.01f, 3);
// Create a shape for the triangle mesh.
_triangleMeshShape = new TriangleMeshShape(mesh);
// Enable contact welding. And set the welding limit to 1 for maximal effect.
_triangleMeshShape.EnableContactWelding = true;
_originalWeldingLimit = TriangleMeshAlgorithm.WeldingLimit;
TriangleMeshAlgorithm.WeldingLimit = 1;
// Optional: Assign a spatial partitioning scheme to the triangle mesh. (A spatial partition
// adds an additional memory overhead, but it improves collision detection speed tremendously!)
_triangleMeshShape.Partition = new CompressedAabbTree() { BottomUpBuildThreshold = 0 };
// Create a static rigid body using the shape and add it to the simulation.
// We explicitly specify a mass frame. We can use any mass frame for static bodies (because
// static bodies are effectively treated as if they have infinite mass). If we do not specify
// a mass frame in the rigid body constructor, the constructor will automatically compute an
// approximate mass frame (which can take some time for large meshes).
var ground = new RigidBody(_triangleMeshShape, new MassFrame(), null)
{
Pose = new Pose(new Vector3F(-34, 0, -40f)),
MotionType = MotionType.Static,
};
Simulation.RigidBodies.Add(ground);
SphereShape sphereShape = new SphereShape(0.5f);
_sphere = new RigidBody(sphereShape);
Simulation.RigidBodies.Add(_sphere);
_enableSmoothMovement = true;
_timeUntilReset = TimeSpan.Zero;
}
public RollingSphereSample(Microsoft.Xna.Framework.Game game)
: base(game)
{
// To demonstrate the problems with triangle meshes we increase the gravity and let a
// sphere roll over a curved surface.
// Add basic force effects.
Simulation.ForceEffects.Add(new Gravity {
Acceleration = new Vector3(0, -30, 0)
}); // Higher gravity to make the problem more visible.
Simulation.ForceEffects.Add(new Damping());
// Use the custom contact filter to improve sphere contacts.
_sphereContactFilter = new SphereContactFilter();
Simulation.CollisionDomain.CollisionDetection.ContactFilter = _sphereContactFilter;
// The triangle mesh could be loaded from a file, such as an XNA Model.
// In this example will create a height field and convert the height field into a triangle mesh.
var numberOfSamplesX = 60;
var numberOfSamplesZ = 10;
var samples = new float[numberOfSamplesX * numberOfSamplesZ];
for (int z = 0; z < numberOfSamplesZ; z++)
{
for (int x = 0; x < numberOfSamplesX; x++)
{
samples[z * numberOfSamplesX + x] = (float)(Math.Sin(x / 6f) * 10f + 5f);
}
}
var heightField = new HeightField(0, 0, 70, 30, samples, numberOfSamplesX, numberOfSamplesZ);
// Convert the height field to a triangle mesh.
ITriangleMesh mesh = heightField.GetMesh(0.01f, 3);
// Create a shape for the triangle mesh.
_triangleMeshShape = new TriangleMeshShape(mesh);
// Enable contact welding. And set the welding limit to 1 for maximal effect.
_triangleMeshShape.EnableContactWelding = true;
_originalWeldingLimit = TriangleMeshAlgorithm.WeldingLimit;
TriangleMeshAlgorithm.WeldingLimit = 1;
// Optional: Assign a spatial partitioning scheme to the triangle mesh. (A spatial partition
// adds an additional memory overhead, but it improves collision detection speed tremendously!)
_triangleMeshShape.Partition = new CompressedAabbTree()
{
BottomUpBuildThreshold = 0
};
// Create a static rigid body using the shape and add it to the simulation.
// We explicitly specify a mass frame. We can use any mass frame for static bodies (because
// static bodies are effectively treated as if they have infinite mass). If we do not specify
// a mass frame in the rigid body constructor, the constructor will automatically compute an
// approximate mass frame (which can take some time for large meshes).
var ground = new RigidBody(_triangleMeshShape, new MassFrame(), null)
{
Pose = new Pose(new Vector3(-34, 0, -40f)),
MotionType = MotionType.Static,
};
Simulation.RigidBodies.Add(ground);
SphereShape sphereShape = new SphereShape(0.5f);
_sphere = new RigidBody(sphereShape);
Simulation.RigidBodies.Add(_sphere);
_enableSmoothMovement = true;
_timeUntilReset = TimeSpan.Zero;
}
