public static void The_returned_distance_is_the_distance_from_the_ray_origin_to_the_closest_edge_of_the_sphere()
{
var sphere = new Sphere(new Point(0, 0, 2), 1);
var ray = new Ray(Point.Zero, Vector.UnitZ);
Assert.Equal(1, sphere.FindClosestIntersectionWith(ray).Distance);
sphere = new Sphere(new Point(0, 0, -2), 1);
ray = new Ray(Point.Zero, -Vector.UnitZ);
Assert.Equal(1, sphere.FindClosestIntersectionWith(ray).Distance);
sphere = new Sphere(new Point(15, 0, 0), 3);
ray = new Ray(Point.Zero, Vector.UnitX);
Assert.Equal(12, sphere.FindClosestIntersectionWith(ray).Distance);
}
public static void If_the_ray_points_at_the_sphere_the_result_is_not_null()
{
var sphere = new Sphere(new Point(0, 0, 5), 1);
var ray = new Ray(Point.Zero, Vector.UnitZ);
Assert.NotNull(sphere.FindClosestIntersectionWith(ray));
}