def test_mixed_hit():
s = Sphere()
i1 = Intersection(-1, s)
i2 = Intersection(1, s)
xs = Intersections(i1, i2)
i = xs.hit()
assert i == i2
def test_positive_hit():
s = Sphere()
i1 = Intersection(1, s)
i2 = Intersection(2, s)
xs = Intersections(i1, i2)
i = xs.hit()
assert i == i1
def test_negative_hit():
s = Sphere()
i1 = Intersection(-2, s)
i2 = Intersection(-1, s)
xs = Intersections(i1, i2)
i = xs.hit()
assert i is None
def test_assert_lowest_hit():
s = Sphere()
i1 = Intersection(5, s)
i2 = Intersection(7, s)
i3 = Intersection(-3, s)
i4 = Intersection(2, s)
xs = Intersections(i1, i2, i3, i4)
i = xs.hit()
assert i == i4
def local_intersect(self, ray: Ray):
a = ray.direction.x**2 + ray.direction.z**2
if abs(a) < EPSILON:
xs = Intersections()
self.intersect_caps(ray, xs)
return xs
b = 2 * ray.origin.x * ray.direction.x + 2 * ray.origin.z * ray.direction.z
c = ray.origin.x**2 + ray.origin.z**2 - 1
disc = b**2 - 4 * a * c
if disc < 0:
return Intersections()
t0 = (-b - math.sqrt(disc)) / (2 * a)
t1 = (-b + math.sqrt(disc)) / (2 * a)
if t0 > t1:
t0, t1 = (t1, t0)
xs = Intersections()
y0 = ray.origin.y + t0 * ray.direction.y
if self.minimum < y0 and y0 < self.maximum:
xs.append(Intersection(t0, self))
y1 = ray.origin.y + t1 * ray.direction.y
if self.minimum < y1 and y1 < self.maximum:
xs.append(Intersection(t1, self))
self.intersect_caps(ray, xs)
return xs
def local_intersect(self, ray: Ray):
xtmin, xtmax = check_axis(ray.origin.x, ray.direction.x)
ytmin, ytmax = check_axis(ray.origin.y, ray.direction.y)
ztmin, ztmax = check_axis(ray.origin.z, ray.direction.z)
tmin = max(xtmin, ytmin, ztmin)
tmax = min(xtmax, ytmax, ztmax)
if tmin > tmax:
return Intersections()
else:
return Intersections(Intersection(tmin, self),
Intersection(tmax, self))
def local_intersect(self, ray: Ray):
obj_to_ray = ray.origin - self.origin
a = ray.direction.dot(ray.direction)
b = 2 * ray.direction.dot(obj_to_ray)
c = obj_to_ray.dot(obj_to_ray) - 1
discriminant = b**2 - 4 * a * c
if discriminant < 0:
return Intersections()
t1 = (-b - math.sqrt(discriminant)) / (2 * a)
t2 = (-b + math.sqrt(discriminant)) / (2 * a)
return Intersections(Intersection(t1, self), Intersection(t2, self))
def test_schlick_perpendicular():
s = GlassSphere()
r = Ray(Point(0, 0, 0), Vector(0, 1, 0))
xs = Intersections(Intersection(-1, s), Intersection(1, s))
comps = xs[1].prepare_computation(r, xs)
reflectance = comps.schlick()
assert equal(reflectance, 0.04)
def test_schlick_small_angle():
s = GlassSphere()
r = Ray(Point(0, 0.99, -2), Vector(0, 0, 1))
xs = Intersections(Intersection(1.8589, s))
comps = xs[0].prepare_computation(r, xs)
reflectance = comps.schlick()
assert equal(reflectance, 0.48873)
def test_aggregate_intersections():
s = Sphere()
i1 = Intersection(1, s)
i2 = Intersection(2, s)
xs = Intersections(i1, i2)
assert len(xs) == 2
assert xs[0].t == 1
assert xs[1].t == 2
def test_schlick_tir():
rt2 = math.sqrt(2) / 2
s = GlassSphere()
r = Ray(Point(0, 0, rt2), Vector(0, 1, 0))
xs = Intersections(Intersection(-rt2, s), Intersection(rt2, s))
comps = xs[1].prepare_computation(r, xs)
reflectance = comps.schlick()
assert reflectance == 1.0
def test_refracted_opaque():
w = World().default()
s = w.objects[0]
r = Ray(Point(0, 0, -5), Vector(0, 0, 1))
xs = Intersections(Intersection(4, s), Intersection(6, s))
comps = xs[0].prepare_computation(r, xs)
c = w.refracted_color(comps, 5)
assert c == Color(0, 0, 0)
def test_under_point():
r = Ray(Point(0, 0, -5), Vector(0, 0, 1))
s = GlassSphere()
s.set_transform(Translation(0, 0, 1))
i = Intersection(5, s)
xs = Intersections(i)
comps = i.prepare_computation(r, xs)
assert comps.under_point.z > EPSILON / 2
assert comps.point.z < comps.under_point.z
def test_refracted_max_depth():
w = World().default()
s = w.objects[0]
s.material.transparency = 1.0
s.material.refractive_index = 1.5
r = Ray(Point(0, 0, -5), Vector(0, 0, 1))
xs = Intersections(Intersection(4, s), Intersection(6, s))
comps = xs[0].prepare_computation(r, xs)
c = w.refracted_color(comps, 0)
assert c == Color(0, 0, 0)
def local_intersect(self, ray: Ray):
dir_cross_e2 = ray.direction.cross(self.e2)
det = self.e1.dot(dir_cross_e2)
if abs(det) < EPSILON:
return Intersections()
f = 1.0 / det
p1_to_origin = ray.origin - self.p1
u = f * p1_to_origin.dot(dir_cross_e2)
if u < 0 or u > 1:
return Intersections()
origin_cross_e1 = p1_to_origin.cross(self.e1)
v = f * ray.direction.dot(origin_cross_e1)
if v < 0 or (u + v) > 1:
return Intersections()
t = f * self.e2.dot(origin_cross_e1)
return Intersections(Intersection(
t, self)) # BOGUS TO TEST AGAINST POSITIVE
def test_refracted_total():
w = World().default()
s = w.objects[0]
s.material.transparency = 1.0
s.material.refractive_index = 1.5
r = Ray(Point(0, 0, math.sqrt(2) / 2), Vector(0, 1, 0))
xs = Intersections(
Intersection(-math.sqrt(2) / 2, s), Intersection(math.sqrt(2) / 2, s)
)
comps = xs[1].prepare_computation(r, xs)
c = w.refracted_color(comps, 5)
assert c == Color(0, 0, 0)
def local_intersect(self, ray: Ray):
total_xs = Intersections()
for obj in self.objects:
xs = obj.intersect(ray)
total_xs.extend(xs)
total_xs.sort()
for x in total_xs:
print(x)
return total_xs
def shade_hit_transparent():
w = World().default()
floor = Plane()
floor.set_transform(Translation(0, -1, 0))
floor.material.transparency = 0.5
floor.material.refractive_index = 1.5
w.objects.append(floor)
ball = Sphere()
ball.material.color = Color(1, 0, 0)
ball.material.ambient = 0.5
ball.set_transform(Translation(0, -3.5, -0.5))
w.objects.append(ball)
r = Ray(Point(0, 0, -3), Vector(0, -math.sqrt(2) / 2, math.sqrt(2) / 2))
xs = Intersections(Intersection(math.sqrt(2), floor))
comps = xs[0].prepare_computations(r, xs)
color = w.shade_hit(comps, 5)
assert color == Color(0.93642, 0.68642, 0.68642)
def test_refracted_color():
w = World().default()
a = w.objects[0]
a.material.ambient = 1.0
a.material.pattern = _TestPattern()
b = w.objects[1]
b.material.transparency = 1.0
b.material.refractive_index = 1.5
r = Ray(Point(0, 0, 0.1), Vector(0, 1, 0))
xs = Intersections(
Intersection(-0.9899, a),
Intersection(-0.4899, b),
Intersection(0.4899, b),
Intersection(0.9899, a),
)
comps = xs[2].prepare_computation(r, xs)
c = w.refracted_color(comps, 5)
print(c)
assert c == Color(0, 0.99888, 0.04725)
def check_n1_n2(index):
a = GlassSphere()
a.set_transform(Scaling(2, 2, 2))
a.material.refractive_index = 1.5
b = GlassSphere()
b.set_transform(Translation(0, 0, -0.25))
b.material.refractive_index = 2.0
c = GlassSphere()
c.set_transform(Translation(0, 0, 0.25))
c.material.refractive_index = 2.5
r = Ray(Point(0, 0, -4), Vector(0, 0, 1))
xs = Intersections(
Intersection(2, a),
Intersection(2.75, b),
Intersection(3.25, c),
Intersection(4.75, b),
Intersection(5.25, c),
Intersection(6, a),
)
comps = xs[index].prepare_computation(r, xs)
return (comps.n1, comps.n2)
def local_intersect(self, ray: Ray):
if abs(ray.direction.y) < EPSILON:
return Intersections()
t = -ray.origin.y / ray.direction.y
return Intersections(Intersection(t, self))
def intersect(self, ray):
xs = Intersections()
for obj in self.objects:
xs.extend(obj.intersect(ray))
xs.sort()
return xs