public void AddCircularObstacle(IObject obj)
{
BoundingSphere bs = BoundingSphere.CreateFromBoundingBox(obj.PhysicObject.BoundingBox.Value);
SphericalObstacle so = new SphericalObstacle(bs.Radius, obj.PhysicObject.Position);
obstacles.Add(so);
}
// xxx experiment cwr 9-6-02
protected void FindNextIntersectionWithSphere(SphericalObstacle obs, ref PathIntersection intersection)
{
// This routine is based on the Paul Bourke's derivation in:
// Intersection of a Line and a Sphere (or circle)
// http://www.swin.edu.au/astronomy/pbourke/geometry/sphereline/
float b, c, d, p, q, s;
Vector3 lc;
// initialize pathIntersection object
intersection.intersect = false;
intersection.obstacle = obs;
// find "local center" (lc) of sphere in boid's coordinate space
lc = this.LocalizePosition(obs.Center);
// computer line-sphere intersection parameters
b = -2 * lc.Z;
c = lc.X * lc.X + lc.Y * lc.Y + lc.Z * lc.Z -
(obs.Radius + this.Radius) * (obs.Radius + this.Radius);
d = (b * b) - (4 * c);
// when the path does not intersect the sphere
if (d < 0)
{
return;
}
// otherwise, the path intersects the sphere in two points with
// parametric coordinates of "p" and "q".
// (If "d" is zero the two points are coincident, the path is tangent)
s = (float)Math.Sqrt(d);
p = (-b + s) / 2;
q = (-b - s) / 2;
// both intersections are behind us, so no potential collisions
if ((p < 0) && (q < 0))
{
return;
}
// at least one intersection is in front of us
intersection.intersect = true;
intersection.distance =
((p > 0) && (q > 0)) ?
// both intersections are in front of us, find nearest one
((p < q) ? p : q) :
// otherwise only one intersections is in front, select it
((p > 0) ? p : q);
}
public void AddCircularObstacle(IObject obj)
{
BoundingSphere bs = BoundingSphere.CreateFromBoundingBox(obj.PhysicObject.BoundingBox.Value);
SphericalObstacle so = new SphericalObstacle(bs.Radius, obj.PhysicObject.Position);
obstacles.Add(so);
}
public void AddCircularObstacle(Vector3 center, float radius)
{
SphericalObstacle so = new SphericalObstacle(radius, center);
obstacles.Add(so);
}
public void AddCircularObstacle(Vector3 center, float radius)
{
SphericalObstacle so = new SphericalObstacle(radius, center);
obstacles.Add(so);
}