def test_sphere_intersection_scaled():
r = Ray(Point(0, 0, -5), Vector(0, 0, 1))
s = Sphere()
s.set_transform(scaling(2, 2, 2))
x = r.intersects(s)
assert len(x) == 2
assert x[0].t == 3
assert x[1].t == 7
def test_hit_positive():
s = Sphere()
i1 = Intersection(s, 1)
i2 = Intersection(s, 2)
x = Intersections(i1, i2)
h = x.hit
assert h == i1
def test_ray_intersects_sphere_object():
r = Ray(Point(0, 0, -5), Vector(0, 0, 1))
s = Sphere()
x = r.intersects(s)
assert len(x) == 2
assert x[0].object == s
assert x[1].object == s
def test_ray_intersect_from_behind():
r = Ray(Point(0, 0, 5), Vector(0, 0, 1))
s = Sphere()
x = r.intersects(s)
assert len(x) == 2
assert x[0].t == -6
assert x[1].t == -4
def test_ray_intersect_from_middle():
r = Ray(Point(0, 0, 0), Vector(0, 0, 1))
s = Sphere()
x = r.intersects(s)
assert len(x) == 2
assert x[0].t == -1
assert x[1].t == 1
def test_ray_intersect_sphere_tangent():
r = Ray(Point(0, 1, -5), Vector(0, 0, 1))
s = Sphere()
x = r.intersects(s)
assert len(x) == 2
assert x[0].t == 5
assert x[1].t == 5
def test_hit_one_negative():
s = Sphere()
i1 = Intersection(s, -1)
i2 = Intersection(s, 2)
x = Intersections(i1, i2)
h = x.hit
assert h == i2
def test_hit_all_negative():
s = Sphere()
i1 = Intersection(s, -1)
i2 = Intersection(s, -2)
x = Intersections(i1, i2)
h = x.hit
assert h is None
def test_intersection_aggregation():
s = Sphere()
i1 = Intersection(s, 1)
i2 = Intersection(s, 2)
x = Intersections(i1, i2)
assert len(x) == 2
assert x[0] == i1
assert x[1] == i2
def test_hit_always_lowest_non_negative():
s = Sphere()
i1 = Intersection(s, -1)
i2 = Intersection(s, 2)
i3 = Intersection(s, 6)
i4 = Intersection(s, 3)
x = Intersections(i1, i2, i3, i4)
h = x.hit
assert h is i2
def test_sphere_normal_at_translate():
s = Sphere()
s.set_transform(translation(0, 1, 0))
n = s.normal_at(Point(0, 1.70711, -0.70711))
assert n == Vector(0, 0.7071067811865475, -0.7071067811865476)
def test_sphere_normal_at_scaled():
s = Sphere()
s.set_transform(scaling(1, 0.5, 1))
n = s.normal_at(Point(0, sqrt(2) / 2, -sqrt(2) / 2))
assert n == Vector(0, 0.9701425001453319, -0.24253562503633297)
def test_sphere_normal_at_arbitrary():
s = Sphere()
n = s.normal_at(Point(sqrt(3) / 3, sqrt(3) / 3, sqrt(3) / 3))
assert n == Vector(sqrt(3) / 3, sqrt(3) / 3, sqrt(3) / 3)
def test_sphere_normal_normalized():
s = Sphere()
n = s.normal_at(Point(sqrt(3) / 3, sqrt(3) / 3, sqrt(3) / 3))
assert n == n.normalize()
def test_sphere_normal_at_x():
s = Sphere()
n = s.normal_at(Point(1, 0, 0))
assert n == Vector(1, 0, 0)
def test_sphere_normal_at_z():
s = Sphere()
n = s.normal_at(Point(0, 0, 1))
assert n == Vector(0, 0, 1)
def test_ray_intersect_sphere_no_intersection():
r = Ray(Point(0, 2, -5), Vector(0, 0, 1))
s = Sphere()
x = r.intersects(s)
assert len(x) == 0
def test_sphere_intersection_translate():
r = Ray(Point(0, 0, -5), Vector(0, 0, 1))
s = Sphere()
s.set_transform(translation(5, 0, 0))
x = r.intersects(s)
assert len(x) == 0
def test_sphere_translate():
s = Sphere()
t = translation(2, 3, 4)
s.set_transform(t)
assert s.transform == t
def test_sphere_default_transform():
s = Sphere()
assert s.transform == IdentityMatrix(4)
from math import pi
from src.canvas import Canvas
from src.color import Color
from src.primitives import Sphere
from src.ray import Ray
from src.transformations import scaling, rotation_z
from src.tupl import Point
s = Sphere()
t = rotation_z(pi / 4) @ scaling(0.5, 1, 1)
s.set_transform(t)
r_origin = Point(0, 0, -5)
wall_z = 10
wall_size = 7
N = 100
c = Canvas(N, N)
pixel_size = wall_size / N
half = wall_size / 2
red = Color(255, 0, 0)
for y in range(c.height):
world_y = half - pixel_size * y
for x in range(c.width):
world_x = -half + pixel_size * x
position = Point(world_x, world_y, wall_z)
r = Ray(r_origin, (position - r_origin).normalize())
X = r.intersects(s)
if X.hit is not None:
c.write_pixel(x, y, red)
def test_sphere_material():
s = Sphere()
m = s.material
assert m == DefaultMaterial()
def test_intersection_init():
s = Sphere()
i = Intersection(s, 3.5)
assert i.t == 3.5
assert i.object == s
def test_sphere_material_assignment():
s = Sphere()
m = Material(Color(1, 1, 1), 2, 1, 0.5, 12)
s.set_material(m)
assert s.material == m
from src.canvas import Canvas
from src.color import Color
from src.lights import PointLight
from src.primitives import Sphere
from src.ray import Ray
from src.tupl import Point
s = Sphere()
r_origin = Point(0, 0, -5)
wall_z = 10
wall_size = 7
light_position = Point(-10, 10, 10)
light_color = Color(1, 1, 1)
light = PointLight(light_position, light_color)
N = 200
c = Canvas(N, N)
pixel_size = wall_size / N
half = wall_size / 2
for y in range(c.height):
world_y = half - pixel_size * y
for x in range(c.width):
world_x = -half + pixel_size * x
position = Point(world_x, world_y, wall_z)
r = Ray(r_origin, (position - r_origin).normalize())
X = r.intersects(s)
if X.hit is not None:
point = r.position(X.hit.t)
