public Vector3D CrossProduct(Vector3D vec)
{
double x = this.Y * vec.Z - this.Z * vec.Y;
double y = -(this.X * vec.Z - this.Z * vec.X);
double z = this.X * vec.Y - this.Y * vec.X;
return new Vector3D(x, y, z);
}
public Vector3D(Vector3D vec)
{
this.X = vec.X;
this.Y = vec.Y;
this.Z = vec.Z;
}