def test_the_color_when_ray_misses(self):
world = default_world()
ray = Ray(point(0, 0, -5), vector(0, 1, 0))
c = color_at(world, ray)
self.assertEqual(color(0, 0, 0), c)
def test_the_color_when_ray_hits(self):
world = default_world()
ray = Ray(point(0, 0, -5), vector(0, 0, 1))
c = color_at(world, ray)
self.assert_tuple_equals(color(0.38066, 0.47583, 0.2855), c, 0.001)
def test_default_world(self):
light = PointLight(point(-10, 10, -10), color(1, 1, 1))
s1 = Sphere()
s2 = Sphere()
s1.material.color = color(0.8, 1.0, 0.6)
s1.material.diffuse = 0.7
s1.material.specular = 0.2
s2.set_transform(scaling(0.5, 0.5, 0.5))
world = default_world()
self.assertEqual(light.position, world.light.position)
self.assertEqual(light.intensity, world.light.intensity)
self.assertEqual(s1.material.color, world.objects[0].material.color)
self.assertEqual(s1.material.diffuse,
world.objects[0].material.diffuse)
self.assertEqual(s1.material.specular,
world.objects[0].material.specular)
self.assertEqual(s2.material.color, world.objects[1].material.color)
self.assertEqual(s2.material.diffuse,
world.objects[1].material.diffuse)
self.assertEqual(s2.material.specular,
world.objects[1].material.specular)
def test_shading_and_intersection(self):
world = default_world()
ray = Ray(point(0, 0, -5), vector(0, 0, 1))
shape = world.objects[0]
xs = Intersection(4, shape)
xs.prepare_hit(ray)
c = shade_hit(world, xs)
self.assert_tuple_equals(color(0.38066, 0.47583, 0.2855), c, 0.001)
def test_the_color_with_an_intersection_behind_the_ray(self):
world = default_world()
outer = world.objects[0]
outer.material.ambient = 1
inner = world.objects[1]
inner.material.ambient = 1
ray = Ray(point(0, 0, 0.75), vector(0, 0, -1))
c = color_at(world, ray)
self.assertEqual(inner.material.color, c)
def test_shading_an_intersection_form_the_inside(self):
world = default_world()
world.light = PointLight(point(0, 0.25, 0), color(1, 1, 1))
ray = Ray(point(0, 0, 0), vector(0, 0, 1))
shape = world.objects[1]
xs = Intersection(0.5, shape)
xs.prepare_hit(ray)
c = shade_hit(world, xs)
self.assert_tuple_equals(color(0.90498, 0.90498, 0.90498), c, 0.001)
def test_intersect_world_with_ray(self):
world = default_world()
ray = Ray(point(0, 0, -5), vector(0, 0, 1))
xs = intersect_world(world, ray)
self.assertEqual(4, len(xs))
self.assertEqual(4, xs[0].t)
self.assertEqual(4.5, xs[1].t)
self.assertEqual(5.5, xs[2].t)
self.assertEqual(6, xs[3].t)
def test_rendering_world_with_camera(self):
w = default_world()
c = Camera(11, 11, pi / 2.0)
from_where = point(0, 0, -5)
to = point(0, 0, 0)
up = vector(0, 1, 0)
c.transform = view_transform(from_where, to, up)
image = render(c, w)
self.assert_tuple_equals(color(0.38066, 0.47583, 0.2855),
image.pixel_at(5, 5), 0.001)