// OnUpdate() is called once per frame.
protected override void OnUpdate(TimeSpan deltaTime)
{
if (_inputService.IsPressed(MouseButtons.Middle, true) || _inputService.IsPressed(Buttons.RightShoulder, true, LogicalPlayerIndex.One))
{
// The user has triggered an explosion.
// The explosion is created at the position that is targeted with the cross-hair.
// We can perform a ray hit-test to find the position. The ray starts at the camera
// position and shoots forward (-z direction).
var cameraGameObject = (CameraObject)_gameObjectService.Objects["Camera"];
var cameraNode = cameraGameObject.CameraNode;
Vector3F cameraPosition = cameraNode.PoseWorld.Position;
Vector3F cameraDirection = cameraNode.PoseWorld.ToWorldDirection(Vector3F.Forward);
// Create a ray for hit-testing.
var ray = new RayShape(cameraPosition, cameraDirection, 1000);
// The ray should stop at the first hit. We only want the first object.
ray.StopsAtFirstHit = true;
// The collision detection requires a CollisionObject.
var rayCollisionObject = new CollisionObject(new GeometricObject(ray, Pose.Identity))
{
// In SampleGame.ResetPhysicsSimulation() a collision filter was set:
// CollisionGroup = 0 ... objects that support hit-testing
// CollisionGroup = 1 ... objects that are ignored during hit-testing
// CollisionGroup = 2 ... objects (rays) for hit-testing
CollisionGroup = 2,
};
// Get the first object that has contact with the ray.
ContactSet contactSet = _simulation.CollisionDomain.GetContacts(rayCollisionObject).FirstOrDefault();
if (contactSet != null && contactSet.Count > 0)
{
// The ray has hit something.
// The contact set contains all detected contacts between the ray and another object.
// Get the first contact in the contact set. (A ray hit usually contains exactly 1 contact.)
Contact contact = contactSet[0];
// Create an explosion at the hit position.
var explosion = new Explosion { Position = contact.Position };
_simulation.ForceEffects.Add(explosion);
// Note: The Explosion force effect removes itself automatically from the simulation once
// it has finished.
}
}
}
/// <summary>
/// Creates an explosion in near the center of the scene.
/// </summary>
private void Explode()
{
Explosion explosion = new Explosion
{
Force = 5e5f,
Position = RandomHelper.Random.NextVector3F(-2, 2),
Radius = 12
};
Simulation.ForceEffects.Add(explosion);
}