public bool Intersect(Plane3D b, out Line3D intersection)
{
intersection = null;
if (IsParallel(b))
{
return(false);
}
Point3D p;
Vector3D v1 = Normal.CrossProduct(b.Normal);
Vector3D v2 = new Vector3D(v1.X * v1.X, v1.Y * v1.Y, v1.Z * v1.Z);
double w1 = -Distance;
double w2 = -b.Distance;
double id;
if ((v2.Z > v2.Y) && (v2.Z > v2.X) && (v2.Z > Double.Epsilon))
{
// point on XY plane
id = 1.0 / v1.Z;
p = new Point3D(Normal.Y * w2 - b.Normal.Y * w1,
b.Normal.X * w1 - Normal.X * w2,
0.0);
}
else if ((v2.Y > v2.X) && (v2.Y > Double.Epsilon))
{
// point on XZ plane
id = -1.0 / v1.Y;
p = new Point3D(Normal.Z * w2 - b.Normal.Z * w1,
0.0,
b.Normal.Y * w1 - Normal.Y * w2);
}
else if (v2.X > Double.Epsilon)
{
// point on YZ plane
id = 1.0 / v1.X;
p = new Point3D(0.0,
Normal.Z * w2 - b.Normal.Z * w1,
b.Normal.Y * w1 - Normal.Y * w2);
}
else
{
return(false);
}
p = (p.ToVector() * id).ToPoint();
id = 1.0 / Math.Sqrt(v2.X + v2.Y + v2.Z);
v1 *= id;
intersection = new Line3D(p, p.ToVector() + v1);
return(true);
}
/// <summary>
/// Polygon constructor.
/// </summary>
/// <param name="vertices">Vertices of the polygon</param>
/// <param name="name">Name of the polygon.</param>
public Polygon3D(IEnumerable <Point3D> vertices, string name) : base(Reorder(vertices, name))
{
// All exception tests are in the method Reorder
Plane = new Plane(this[1], this[0], this[2]);
Normal = Plane.Normal;
Center = Point3D.Centroid(this);
Radius = this.Max(point => point.DistanceTo(Center));
Name = name;
var edges = this.Select((t, i) => new Line3D(t, this[++i % Count]));
Edges = new ReadOnlyCollection <Line3D>(edges.ToList());
var borderNormals = Edges.Select(edge => Normal.CrossProduct(edge.Direction).Negate());
v_EdgeNormals = new ReadOnlyCollection <UnitVector3D>(borderNormals.ToList());
var offsets = this.Select((t, i) => - t.ToVector3D().DotProduct(v_EdgeNormals[i]));
v_D = new ReadOnlyCollection <double>(offsets.ToList());
}