def precomputing_the_reflection_vector():
# Given
shape = Plane()
r = Ray(Point(0, 1, -1), Vector(0, -sqrt(2) / 2, sqrt(2) / 2))
i = Intersection(sqrt(2), shape)
# When
comps = i.prepare_computations(r)
# Then
assert comps.reflectv == Vector(0, sqrt(2) / 2, sqrt(2) / 2)
def test_the_hit__when_an_intersection_occurs_on_the_outside():
# Given
r = Ray(Point(0, 0, -5), Vector(0, 0, 1))
shape = Sphere()
i = Intersection(4, shape)
# When
comps = i.prepare_computations(r)
# Then
assert comps.inside is False
def test_the_hit_should_offset_the_point():
# Given
r = Ray(Point(0, 0, -5), Vector(0, 0, 1))
shape = Sphere()
shape.transform = translation(0, 0, 1)
i = Intersection(5, shape)
# When
comps = i.prepare_computations(r)
# Then
assert comps.over_point.z < -EPSILON / 2
assert comps.point.z > comps.over_point.z
def test_shading_an_intersection():
# Given
w = default_world()
r = Ray(Point(0, 0, -5), Vector(0, 0, 1))
shape = w.objects[0]
i = Intersection(4, shape)
# When
comps = i.prepare_computations(r)
c = w.shade_hit(comps)
# Then
assert c == Color(0.38066, 0.47583, 0.2855)
def test_the_under_point_is_offset_below_the_surface():
# Given
r = Ray(Point(0, 0, -5), Vector(0, 0, 1))
shape = glass_sphere()
shape.transform = translation(0, 0, 1)
i = Intersection(5, shape)
xs = Intersections(i)
# When
comps = i.prepare_computations(r, xs)
# Then
assert comps.under_point.z > EPSILON / 2
assert comps.point.z < comps.under_point.z
def test_the_hit__when_an_intersection_occurs_on_the_inside():
# Given
r = Ray(Point(0, 0, 0), Vector(0, 0, 1))
shape = Sphere()
i = Intersection(1, shape)
# When
comps = i.prepare_computations(r)
# Then
assert comps.point == Point(0, 0, 1)
assert comps.eyev == Vector(0, 0, -1)
assert comps.inside is True
assert comps.normalv == Vector(0, 0, -1)
def test_shading_an_intersection_from_the_inside():
# Given
w = default_world()
w.light = PointLight(Point(0, 0.25, 0), Color(1, 1, 1))
r = Ray(Point(0, 0, 0), Vector(0, 0, 1))
shape = w.objects[1]
i = Intersection(0.5, shape)
# When
comps = i.prepare_computations(r)
c = w.shade_hit(comps)
# Then
assert c == Color(0.90498, 0.90498, 0.90498)
def test_the_reflected_color_for_a_nonreflective_material():
# Given
w = default_world()
r = Ray(Point(0, 0, 0), Vector(0, 0, 1))
shape = Sphere()
shape.material.ambient = 1
i = Intersection(1, shape)
# When
comps = i.prepare_computations(r)
color = w.reflected_color(comps)
# Then
assert color == Color(0, 0, 0) # black
def test_precomputing_the_state_of_an_intersection():
# Given
r = Ray(Point(0, 0, -5), Vector(0, 0, 1))
shape = Sphere()
i = Intersection(4, shape)
# When
comps = i.prepare_computations(r)
# Then
assert comps.t == i.t
assert comps.object == i.object
assert comps.point == Point(0, 0, -1)
assert comps.eyev == Vector(0, 0, -1)
assert comps.normalv == Vector(0, 0, -1)
def test_the_reflected_color_at_the_maximum_recursive_depth():
# Given
w = default_world()
shape = Plane()
shape.material.reflective = 0.5
shape.transform = translation(0, -1, 0)
w.objects.append(shape)
r = Ray(Point(0, 0, -3), Vector(0, -sqrt(2) / 2, sqrt(2) / 2))
i = Intersection(sqrt(2), shape)
# When
comps = i.prepare_computations(r)
color = w.reflected_color(comps, 0)
# Then
assert color == Color(0, 0, 0)
def test__shade_hit__with_a_reflective_material():
# Given
w = default_world()
shape = Plane()
shape.material.reflective = 0.5
shape.transform = translation(0, -1, 0)
w.objects.append(shape)
r = Ray(Point(0, 0, -3), Vector(0, -sqrt(2) / 2, sqrt(2) / 2))
i = Intersection(sqrt(2), shape)
# When
comps = i.prepare_computations(r)
color = w.shade_hit(comps)
# Then
assert color == Color(0.87675, 0.92434, 0.82918)
def test__shade_hit__is_given_an_intersection_in_shadow():
# Given
w = World()
w.light = PointLight(Point(0, 0, -10), Color(1, 1, 1))
s1 = Sphere()
w.objects.append(s1)
s2 = Sphere()
s2.transform = translation(0, 0, 10)
w.objects.append(s2)
r = Ray(Point(0, 0, 5), Vector(0, 0, 1))
i = Intersection(4, s2)
# When
comps = i.prepare_computations(r)
c = w.shade_hit(comps)
# Then
assert c == Color(0.1, 0.1, 0.1)