public CollisionDetectionSample(Microsoft.Xna.Framework.Game game)
: base(game)
{
SampleFramework.IsMouseVisible = false;
GraphicsScreen.ClearBackground = true;
GraphicsScreen.BackgroundColor = Color.CornflowerBlue;
SetCamera(new Vector3F(0, 1, 10), 0, 0);
// ----- Initialize collision detection and create objects.
// Create a geometric object with a box shape.
// Position it on the left with an arbitrary rotation.
var geometricObjectA = new GeometricObject(
new BoxShape(1, 2, 3),
new Pose(new Vector3F(-2, -1, 0), Matrix33F.CreateRotationZ(0.1f)));
// Create a geometric object with a capsule shape.
// Position it on the right with an arbitrary rotation.
var geometricObjectB = new GeometricObject(
new CapsuleShape(1, 3),
new Pose(new Vector3F(2, -1, 0), Matrix33F.CreateRotationZ(-0.2f)));
// Create a geometric object with a complex shape that is the convex hull of
// a circle and a rectangle. Position it on the top with an arbitrary rotation.
// (A ConvexHullOfShapes is a collection of different shapes with different
// positions and orientations. The ConvexHullOfShapes combines these shapes
// into a single shape by building their convex hull.)
var complexShape = new ConvexHullOfShapes();
complexShape.Children.Add(new GeometricObject(new RectangleShape(1, 1), new Pose(new Vector3F(0, 0, 1))));
complexShape.Children.Add(new GeometricObject(new CircleShape(1), new Pose(new Vector3F(0, 0, -1))));
var geometricObjectC = new GeometricObject(
complexShape,
new Pose(new Vector3F(0, 2, 0), QuaternionF.CreateRotation(Vector3F.UnitZ, new Vector3F(1, 1, 1))));
// Create collision objects for the geometric objects.
// (A collision object is just a wrapper around the geometric object that
// stores additional information that is required by the collision detection.)
_collisionObjectA = new CollisionObject(geometricObjectA);
_collisionObjectB = new CollisionObject(geometricObjectB);
_collisionObjectC = new CollisionObject(geometricObjectC);
// Create a collision detection.
// (The CollisionDetection stores general parameters and it can be used to
// perform closest-point and contact queries.)
_collisionDetection = new CollisionDetection();
// Create a new collision domain and add the collision objects.
// (A CollisionDomain manages multiple collision objects. It improves the
// performance of contact queries by reusing results of the last frame.)
_domain = new CollisionDomain(_collisionDetection);
_domain.CollisionObjects.Add(_collisionObjectA);
_domain.CollisionObjects.Add(_collisionObjectB);
_domain.CollisionObjects.Add(_collisionObjectC);
}
public ShapesSample(Microsoft.Xna.Framework.Game game)
: base(game)
{
// Add basic force effects.
Simulation.ForceEffects.Add(new Gravity());
Simulation.ForceEffects.Add(new Damping());
// Add a ground plane.
RigidBody groundPlane = new RigidBody(new PlaneShape(Vector3F.UnitY, 0))
{
Name = "GroundPlane", // Names are not required but helpful for debugging.
MotionType = MotionType.Static,
};
Simulation.RigidBodies.Add(groundPlane);
// ----- Add a sphere.
Shape sphere = new SphereShape(0.5f);
Simulation.RigidBodies.Add(new RigidBody(sphere));
// ----- Add a box.
BoxShape box = new BoxShape(0.5f, 0.9f, 0.7f);
Simulation.RigidBodies.Add(new RigidBody(box));
// ----- Add a capsule.
CapsuleShape capsule = new CapsuleShape(0.4f, 1.2f);
Simulation.RigidBodies.Add(new RigidBody(capsule));
// ----- Add a cone.
ConeShape cone = new ConeShape(0.5f, 1f);
Simulation.RigidBodies.Add(new RigidBody(cone));
// ----- Add a cylinder.
CylinderShape cylinder = new CylinderShape(0.3f, 1f);
Simulation.RigidBodies.Add(new RigidBody(cylinder));
// ----- Add a convex hull of random points.
ConvexHullOfPoints convexHullOfPoints = new ConvexHullOfPoints();
for (int i = 0; i < 20; i++)
convexHullOfPoints.Points.Add(RandomHelper.Random.NextVector3F(-0.5f, 0.5f));
Simulation.RigidBodies.Add(new RigidBody(convexHullOfPoints));
// ----- Add a convex polyhedron.
// (A ConvexPolyhedron is similar to the ConvexHullOfPoints. The difference is that
// the points in a ConvexHullOfPoints can be changed at runtime. A ConvexPolyhedron
// cannot be changed at runtime, but it is faster.)
List<Vector3F> points = new List<Vector3F>();
for (int i = 0; i < 20; i++)
points.Add(RandomHelper.Random.NextVector3F(-0.7f, 0.7f));
ConvexPolyhedron convexPolyhedron = new ConvexPolyhedron(points);
Simulation.RigidBodies.Add(new RigidBody(convexPolyhedron));
// ----- Add a composite shape (a table that consists of 5 boxes).
CompositeShape composite = new CompositeShape();
composite.Children.Add(new GeometricObject(new BoxShape(0.1f, 0.8f, 0.1f), new Pose(new Vector3F(-0.75f, 0.4f, -0.5f))));
composite.Children.Add(new GeometricObject(new BoxShape(0.1f, 0.8f, 0.1f), new Pose(new Vector3F(0.75f, 0.4f, -0.5f))));
composite.Children.Add(new GeometricObject(new BoxShape(0.1f, 0.8f, 0.1f), new Pose(new Vector3F(-0.75f, 0.4f, 0.5f))));
composite.Children.Add(new GeometricObject(new BoxShape(0.1f, 0.8f, 0.1f), new Pose(new Vector3F(0.75f, 0.4f, 0.5f))));
composite.Children.Add(new GeometricObject(new BoxShape(1.8f, 0.1f, 1.1f), new Pose(new Vector3F(0, 0.8f, 0))));
Simulation.RigidBodies.Add(new RigidBody(composite));
// ----- Add a convex hull of multiple shapes.
ConvexHullOfShapes convexHullOfShapes = new ConvexHullOfShapes();
convexHullOfShapes.Children.Add(new GeometricObject(new CylinderShape(0.2f, 0.8f), new Pose(new Vector3F(-0.4f, 0, 0))));
convexHullOfShapes.Children.Add(new GeometricObject(new CylinderShape(0.2f, 0.8f), new Pose(new Vector3F(+0.4f, 0, 0))));
Simulation.RigidBodies.Add(new RigidBody(convexHullOfShapes));
// ----- Add the Minkowski sum of two shapes.
// (The Minkowski sum is a mathematical operation that combines two shapes.
// Here a circle is combined with a sphere. The result is a wheel.)
MinkowskiSumShape minkowskiSum = new MinkowskiSumShape();
minkowskiSum.ObjectA = new GeometricObject(new SphereShape(0.2f), Pose.Identity);
minkowskiSum.ObjectB = new GeometricObject(new CircleShape(0.5f), Pose.Identity);
Simulation.RigidBodies.Add(new RigidBody(minkowskiSum));
// Create another Minkowski sum. (Here a small sphere is added to a box to create a
// box with rounded corners.)
minkowskiSum = new MinkowskiSumShape();
minkowskiSum.ObjectA = new GeometricObject(new SphereShape(0.1f), Pose.Identity);
minkowskiSum.ObjectB = new GeometricObject(new BoxShape(0.2f, 0.5f, 0.8f), Pose.Identity);
Simulation.RigidBodies.Add(new RigidBody(minkowskiSum));
// ----- Add a triangle mesh.
// A triangle mesh could be loaded from a file or built from an XNA model.
// Here we first create a composite shape and convert the shape into a triangle
// mesh. (Any Shape in DigitalRune.Geometry can be converted to a triangle mesh.)
CompositeShape dumbbell = new CompositeShape();
dumbbell.Children.Add(new GeometricObject(new SphereShape(0.4f), new Pose(new Vector3F(0.6f, 0.0f, 0.0f))));
dumbbell.Children.Add(new GeometricObject(new SphereShape(0.4f), new Pose(new Vector3F(-0.6f, 0.0f, 0.0f))));
dumbbell.Children.Add(new GeometricObject(new CylinderShape(0.1f, 0.6f), new Pose(Matrix33F.CreateRotationZ(ConstantsF.PiOver2))));
TriangleMeshShape triangleMeshShape = new TriangleMeshShape(dumbbell.GetMesh(0.01f, 2));
// Optional: We can enable "contact welding". When this flag is enabled, the triangle shape
// precomputes additional internal information for the mesh. The collision detection will
// be able to compute better contacts (e.g. better normal vectors at triangle edges).
// Pro: Collision detection can compute better contact information.
// Con: Contact welding information needs a bit of memory. And the collision detection is
// a bit slower.
triangleMeshShape.EnableContactWelding = true;
// 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 AabbTree<int>()
{
// The tree is automatically built using a mixed top-down/bottom-up approach. Bottom-up
// building is slower but produces better trees. If the tree building takes too long,
// we can lower the BottomUpBuildThreshold (default is 128).
BottomUpBuildThreshold = 0,
};
Simulation.RigidBodies.Add(new RigidBody(triangleMeshShape));
// ----- Set random positions/orientations.
// (Start with the second object. The first object is the ground plane which should
// not be changed.)
for (int i = 1; i < Simulation.RigidBodies.Count; i++)
{
RigidBody body = Simulation.RigidBodies[i];
Vector3F position = RandomHelper.Random.NextVector3F(-3, 3);
position.Y = 3; // Position the objects 3m above ground.
QuaternionF orientation = RandomHelper.Random.NextQuaternionF();
body.Pose = new Pose(position, orientation);
}
}
// Creates a lot of random objects.
private void CreateRandomObjects()
{
var random = new Random();
var isFirstHeightField = true;
int currentShape = 0;
int numberOfObjects = 0;
while (true)
{
numberOfObjects++;
if (numberOfObjects > ObjectsPerType)
{
currentShape++;
numberOfObjects = 0;
}
Shape shape;
switch (currentShape)
{
case 0:
// Box
shape = new BoxShape(ObjectSize, ObjectSize * 2, ObjectSize * 3);
break;
case 1:
// Capsule
shape = new CapsuleShape(0.3f * ObjectSize, 2 * ObjectSize);
break;
case 2:
// Cone
shape = new ConeShape(1 * ObjectSize, 2 * ObjectSize);
break;
case 3:
// Cylinder
shape = new CylinderShape(0.4f * ObjectSize, 2 * ObjectSize);
break;
case 4:
// Sphere
shape = new SphereShape(ObjectSize);
break;
case 5:
// Convex hull of several points.
ConvexHullOfPoints hull = new ConvexHullOfPoints();
hull.Points.Add(new Vector3F(-1 * ObjectSize, -2 * ObjectSize, -1 * ObjectSize));
hull.Points.Add(new Vector3F(2 * ObjectSize, -1 * ObjectSize, -0.5f * ObjectSize));
hull.Points.Add(new Vector3F(1 * ObjectSize, 2 * ObjectSize, 1 * ObjectSize));
hull.Points.Add(new Vector3F(-1 * ObjectSize, 2 * ObjectSize, 1 * ObjectSize));
hull.Points.Add(new Vector3F(-1 * ObjectSize, 0.7f * ObjectSize, -0.6f * ObjectSize));
shape = hull;
break;
case 6:
// A composite shape: two boxes that form a "T" shape.
var composite = new CompositeShape();
composite.Children.Add(
new GeometricObject(
new BoxShape(ObjectSize, 3 * ObjectSize, ObjectSize),
new Pose(new Vector3F(0, 0, 0))));
composite.Children.Add(
new GeometricObject(
new BoxShape(2 * ObjectSize, ObjectSize, ObjectSize),
new Pose(new Vector3F(0, 2 * ObjectSize, 0))));
shape = composite;
break;
case 7:
shape = new CircleShape(ObjectSize);
break;
case 8:
{
var compBvh = new CompositeShape();
compBvh.Children.Add(new GeometricObject(new BoxShape(0.5f, 1, 0.5f), new Pose(new Vector3F(0, 0.5f, 0), Matrix33F.Identity)));
compBvh.Children.Add(new GeometricObject(new BoxShape(0.8f, 0.5f, 0.5f), new Pose(new Vector3F(0.5f, 0.7f, 0), Matrix33F.CreateRotationZ(-MathHelper.ToRadians(15)))));
compBvh.Children.Add(new GeometricObject(new SphereShape(0.3f), new Pose(new Vector3F(0, 1.15f, 0), Matrix33F.Identity)));
compBvh.Children.Add(new GeometricObject(new CapsuleShape(0.2f, 1), new Pose(new Vector3F(0.6f, 1.15f, 0), Matrix33F.CreateRotationX(0.3f))));
compBvh.Partition = new AabbTree<int>();
shape = compBvh;
break;
}
case 9:
CompositeShape comp = new CompositeShape();
comp.Children.Add(new GeometricObject(new BoxShape(0.5f * ObjectSize, 1 * ObjectSize, 0.5f * ObjectSize), new Pose(new Vector3F(0, 0.5f * ObjectSize, 0), QuaternionF.Identity)));
comp.Children.Add(new GeometricObject(new BoxShape(0.8f * ObjectSize, 0.5f * ObjectSize, 0.5f * ObjectSize), new Pose(new Vector3F(0.3f * ObjectSize, 0.7f * ObjectSize, 0), QuaternionF.CreateRotationZ(-MathHelper.ToRadians(45)))));
comp.Children.Add(new GeometricObject(new SphereShape(0.3f * ObjectSize), new Pose(new Vector3F(0, 1.15f * ObjectSize, 0), QuaternionF.Identity)));
shape = comp;
break;
case 10:
shape = new ConvexHullOfPoints(new[]
{
new Vector3F(-1 * ObjectSize, -2 * ObjectSize, -1 * ObjectSize),
new Vector3F(2 * ObjectSize, -1 * ObjectSize, -0.5f * ObjectSize),
new Vector3F(1 * ObjectSize, 2 * ObjectSize, 1 * ObjectSize),
new Vector3F(-1 * ObjectSize, 2 * ObjectSize, 1 * ObjectSize),
new Vector3F(-1 * ObjectSize, 0.7f * ObjectSize, -0.6f * ObjectSize)
});
break;
case 11:
ConvexHullOfShapes shapeHull = new ConvexHullOfShapes();
shapeHull.Children.Add(new GeometricObject(new SphereShape(0.3f * ObjectSize), new Pose(new Vector3F(0, 2 * ObjectSize, 0), Matrix33F.Identity)));
shapeHull.Children.Add(new GeometricObject(new BoxShape(1 * ObjectSize, 2 * ObjectSize, 3 * ObjectSize), Pose.Identity));
shape = shapeHull;
break;
case 12:
shape = Shape.Empty;
break;
case 13:
var numberOfSamplesX = 10;
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.Cos(z / 3f) * Math.Sin(x / 2f) * BoxSize / 6);
HeightField heightField = new HeightField(0, 0, 2 * BoxSize, 2 * BoxSize, samples, numberOfSamplesX, numberOfSamplesZ);
shape = heightField;
break;
//case 14:
//shape = new LineShape(new Vector3F(0.1f, 0.2f, 0.3f), new Vector3F(0.1f, 0.2f, -0.3f).Normalized);
//break;
case 15:
shape = new LineSegmentShape(
new Vector3F(0.1f, 0.2f, 0.3f), new Vector3F(0.1f, 0.2f, 0.3f) + 3 * ObjectSize * new Vector3F(0.1f, 0.2f, -0.3f));
break;
case 16:
shape = new MinkowskiDifferenceShape
{
ObjectA = new GeometricObject(new SphereShape(0.1f * ObjectSize)),
ObjectB = new GeometricObject(new BoxShape(1 * ObjectSize, 2 * ObjectSize, 3 * ObjectSize))
};
break;
case 17:
shape = new MinkowskiSumShape
{
ObjectA = new GeometricObject(new SphereShape(0.1f * ObjectSize)),
ObjectB = new GeometricObject(new BoxShape(1 * ObjectSize, 2 * ObjectSize, 3 * ObjectSize)),
};
break;
case 18:
shape = new OrthographicViewVolume(0, ObjectSize, 0, ObjectSize, ObjectSize / 2, ObjectSize * 2);
break;
case 19:
shape = new PerspectiveViewVolume(MathHelper.ToRadians(60f), 16f / 10, ObjectSize / 2, ObjectSize * 3);
break;
case 20:
shape = new PointShape(0.1f, 0.3f, 0.2f);
break;
case 21:
shape = new RayShape(new Vector3F(0.2f, 0, -0.12f), new Vector3F(1, 2, 3).Normalized, ObjectSize * 2);
break;
case 22:
shape = new RayShape(new Vector3F(0.2f, 0, -0.12f), new Vector3F(1, 2, 3).Normalized, ObjectSize * 2)
{
StopsAtFirstHit = true
};
break;
case 23:
shape = new RectangleShape(ObjectSize, ObjectSize * 2);
break;
case 24:
shape = new TransformedShape(
new GeometricObject(
new BoxShape(1 * ObjectSize, 2 * ObjectSize, 3 * ObjectSize),
new Pose(new Vector3F(0.1f, 1, -0.2f))));
break;
case 25:
shape = new TriangleShape(
new Vector3F(ObjectSize, 0, 0), new Vector3F(0, ObjectSize, 0), new Vector3F(ObjectSize, ObjectSize, ObjectSize));
break;
//case 26:
// {
// // Create a composite object from which we get the mesh.
// CompositeShape compBvh = new CompositeShape();
// compBvh.Children.Add(new GeometricObject(new BoxShape(0.5f, 1, 0.5f), new Pose(new Vector3F(0, 0.5f, 0), Matrix33F.Identity)));
// compBvh.Children.Add(
// new GeometricObject(
// new BoxShape(0.8f, 0.5f, 0.5f),
// new Pose(new Vector3F(0.5f, 0.7f, 0), Matrix33F.CreateRotationZ(-(float)MathHelper.ToRadians(15)))));
// compBvh.Children.Add(new GeometricObject(new SphereShape(0.3f), new Pose(new Vector3F(0, 1.15f, 0), Matrix33F.Identity)));
// compBvh.Children.Add(
// new GeometricObject(new CapsuleShape(0.2f, 1), new Pose(new Vector3F(0.6f, 1.15f, 0), Matrix33F.CreateRotationX(0.3f))));
// TriangleMeshShape meshBvhShape = new TriangleMeshShape { Mesh = compBvh.GetMesh(0.01f, 3) };
// meshBvhShape.Partition = new AabbTree<int>();
// shape = meshBvhShape;
// break;
// }
//case 27:
// {
// // Create a composite object from which we get the mesh.
// CompositeShape compBvh = new CompositeShape();
// compBvh.Children.Add(new GeometricObject(new BoxShape(0.5f, 1, 0.5f), new Pose(new Vector3F(0, 0.5f, 0), QuaternionF.Identity)));
// compBvh.Children.Add(
// new GeometricObject(
// new BoxShape(0.8f, 0.5f, 0.5f),
// new Pose(new Vector3F(0.5f, 0.7f, 0), QuaternionF.CreateRotationZ(-(float)MathHelper.ToRadians(15)))));
// compBvh.Children.Add(new GeometricObject(new SphereShape(0.3f), new Pose(new Vector3F(0, 1.15f, 0), QuaternionF.Identity)));
// compBvh.Children.Add(
// new GeometricObject(new CapsuleShape(0.2f, 1), new Pose(new Vector3F(0.6f, 1.15f, 0), QuaternionF.CreateRotationX(0.3f))));
// TriangleMeshShape meshBvhShape = new TriangleMeshShape { Mesh = compBvh.GetMesh(0.01f, 3) };
// meshBvhShape.Partition = new AabbTree<int>();
// shape = meshBvhShape;
// break;
// }
case 28:
shape = new ConvexPolyhedron(new[]
{
new Vector3F(-1 * ObjectSize, -2 * ObjectSize, -1 * ObjectSize),
new Vector3F(2 * ObjectSize, -1 * ObjectSize, -0.5f * ObjectSize),
new Vector3F(1 * ObjectSize, 2 * ObjectSize, 1 * ObjectSize),
new Vector3F(-1 * ObjectSize, 2 * ObjectSize, 1 * ObjectSize),
new Vector3F(-1 * ObjectSize, 0.7f * ObjectSize, -0.6f * ObjectSize)
});
break;
case 29:
return;
default:
currentShape++;
continue;
}
// Create an object with the random shape, pose, color and velocity.
Pose randomPose = new Pose(
random.NextVector3F(-BoxSize + ObjectSize * 2, BoxSize - ObjectSize * 2),
random.NextQuaternionF());
var newObject = new MovingGeometricObject
{
Pose = randomPose,
Shape = shape,
LinearVelocity = random.NextQuaternionF().Rotate(new Vector3F(MaxLinearVelocity, 0, 0)),
AngularVelocity = random.NextQuaternionF().Rotate(Vector3F.Forward)
* RandomHelper.Random.NextFloat(0, MaxAngularVelocity),
};
if (RandomHelper.Random.NextBool())
newObject.LinearVelocity = Vector3F.Zero;
if (RandomHelper.Random.NextBool())
newObject.AngularVelocity = Vector3F.Zero;
if (shape is LineShape || shape is HeightField)
{
// Do not move lines or the height field.
newObject.LinearVelocity = Vector3F.Zero;
newObject.AngularVelocity = Vector3F.Zero;
}
// Create only 1 heightField!
if (shape is HeightField)
{
if (isFirstHeightField)
{
isFirstHeightField = true;
newObject.Pose = new Pose(new Vector3F(-BoxSize, -BoxSize, -BoxSize));
}
else
{
currentShape++;
numberOfObjects = 0;
continue;
}
}
// Add collision object to collision domain.
_domain.CollisionObjects.Add(new CollisionObject(newObject));
//co.Type = CollisionObjectType.Trigger;
//co.Name = "Object" + shape.GetType().Name + "_" + i;
}
}