def default_world():
light = PointLight(point(-10, 10, -10), white)
m = Material(color=color(0.8, 1.0, 0.6), diffuse=0.7, specular=0.2)
s1 = Sphere(material=m)
s2 = Sphere(transformation=scaling(0.5, 0.5, 0.5))
return World(light, s1, s2)
def test_intersecting_a_scaled_sphere_with_a_ray():
sphere = Sphere(transformation=transformations.scaling(2, 2, 2))
ray = Ray(point(0, 0, -5), vector(0, 0, 1))
xs = sphere.intersect(ray)
assert(xs[0].t == 3)
assert(xs[1].t == 7)
def test_multiplying_the_inverse_of_a_scaling_matrix():
transform = transformations.scaling(2, 3, 4)
inverse = transformations.invert(transform)
v = vector(-4, 6, 8)
expected = vector(-2, 2, 2)
actual = inverse(v)
assert ((expected == actual).all())
def test_computing_the_normal_on_a_transformed_sphere():
s = transformations.scaling(1, 0.5, 1)
r = transformations.rotation_z(math.pi/5)
transform = transformations.concat(s, r)
sphere = Sphere(transform)
n = sphere.normal_at(point(0, math.sqrt(2)/2, -math.sqrt(2)/2))
assert(np.allclose(vector(0, 0.97014, -0.242535), n))
def test_chained_transofrmations_must_be_applied_in_reverse_order():
p = point(1, 0, 1)
A = transformations.rotation_x(math.pi / 2)
B = transformations.scaling(5, 5, 5)
C = transformations.translation(10, 5, 7)
CBA = transformations.concat(C, B, A)
assert (np.allclose(point(15, 0, 7), CBA(p)))
def test_scaling_a_ray():
origin = point(1, 2, 3)
direction = vector(0, 1, 0)
r = Ray(origin, direction)
m = transformations.scaling(2, 3, 4)
scaled_ray = r.transform(m)
assert (np.allclose(point(2, 6, 12), scaled_ray.origin))
assert (np.allclose(vector(0, 3, 0), scaled_ray.direction))
def test_a_transformation_matrix_looking_in_positive_z_direction():
from_ = point(0, 0, 0)
to = point(0, 0, 1)
up = vector(0, 1, 0)
t = view_transformation(from_, to, up)
actual_transform_matrix = t(identity_matrix())
expected_transform_matrix = scaling(-1, 1, -1)(identity_matrix())
assert (np.allclose(actual_transform_matrix, expected_transform_matrix))
def test_individual_transformations_are_applied_in_sequence():
p = point(1, 0, 1)
A = transformations.rotation_x(math.pi / 2)
B = transformations.scaling(5, 5, 5)
C = transformations.translation(10, 5, 7)
p2 = A(p)
assert (np.allclose(point(1, -1, 0), p2))
p3 = B(p2)
assert (np.allclose(point(5, -5, 0), p3))
p4 = C(p3)
assert (np.allclose(point(15, 0, 7), p4))
def test_reflection_is_scaling_by_a_negative_value():
transform = transformations.scaling(-1, 1, 1)
p = point(2, 3, 4)
assert ((point(-2, 3, 4) == (transform(p))).all())
def test_a_scaling_matrix_applied_to_a_vecor():
transform = transformations.scaling(2, 3, 4)
v = vector(-4, 6, 8)
assert ((vector(-8, 18, 32) == (transform(v))).all())
def test_a_scaling_matrix_applied_to_a_point():
transform = transformations.scaling(2, 3, 4)
p = point(-4, 6, 8)
assert ((point(-8, 18, 32) == (transform(p))).all())
from pytracer.spheres import Sphere
from pytracer.transformations import scaling, rotation_y, rotation_x, translation, concat, view_transformation
from pytracer.materials import Material
from pytracer.colors import color
from pytracer.camera import Camera
from pytracer.tuples import point, vector
from pytracer.lights import PointLight
from pytracer.world import World
import math
floor_material = Material(color=color(1, 0.9, 0.9), specular=0)
floor = Sphere(transformation=scaling(10, 0.01, 10), material=floor_material)
left_wall_transformation = concat(translation(0, 0,
5), rotation_y(-math.pi / 4),
rotation_x(math.pi / 2),
scaling(10, 0.01, 10))
left_wall = Sphere(transformation=left_wall_transformation,
material=floor_material)
right_wall_transform = concat(translation(0, 0, 5), rotation_y(math.pi / 4),
rotation_x(math.pi / 2), scaling(10, 0.01, 10))
right_wall = Sphere(transformation=right_wall_transform,
material=floor_material)
middle_transform = translation(-0.5, 1, 0.5)
middle_material = Material(color=color(0.1, 1, 0.5), diffuse=0.7, specular=0.3)
middle = Sphere(material=middle_material, transformation=middle_transform)
right_transform = concat(translation(1.5, 0.5, -0.5), scaling(0.5, 0.5, 0.5))
right_material = Material(color=color(0.5, 1, 0.1), diffuse=0.7, specular=0.3)
