def random_scene(aspect_ratio: float, time0: float, time1: float) \
-> Tuple[BVHNode, Camera]:
world = HittableList()
# ground_material = Lambertian(SolidColor(0.5, 0.5, 0.5))
ground_material = Lambertian(
CheckerTexture(SolidColor(0.2, 0.3, 0.1), SolidColor(0.9, 0.9, 0.9)))
world.add(Sphere(Point3(0, -1000, 0), 1000, ground_material))
for a in range(-11, 11):
for b in range(-11, 11):
choose_mat = random_float()
center = Point3(a + 0.9 * random_float(), 0.2,
b + 0.9 * random_float())
if (center - Vec3(4, 0.2, 0)).length() > 0.9:
if choose_mat < 0.6:
# Diffuse
albedo = Color.random() * Color.random()
sphere_material_diffuse = Lambertian(SolidColor(albedo))
center2 = center + Vec3(0, random_float(0, 0.5), 0)
world.add(
MovingSphere(center, center2, 0, 1, 0.2,
sphere_material_diffuse))
elif choose_mat < 0.8:
# Metal
albedo = Color.random(0.5, 1)
fuzz = random_float(0, 0.5)
sphere_material_metal = Metal(albedo, fuzz)
world.add(Sphere(center, 0.2, sphere_material_metal))
else:
# Glass
sphere_material_glass = Dielectric(1.5)
world.add(Sphere(center, 0.2, sphere_material_glass))
material_1 = Dielectric(1.5)
world.add(Sphere(Point3(0, 1, 0), 1, material_1))
material_2 = Lambertian(SolidColor(0.4, 0.2, 0.1))
world.add(Sphere(Point3(-4, 1, 0), 1, material_2))
material_3 = Metal(Color(0.7, 0.6, 0.5), 0)
world.add(Sphere(Point3(4, 1, 0), 1, material_3))
world_bvh = BVHNode(world.objects, time0, time1)
lookfrom = Point3(13, 2, 3)
lookat = Point3(0, 0, 0)
vup = Vec3(0, 1, 0)
vfov = 20
dist_to_focus: float = 10
aperture: float = 0.1
cam = Camera(lookfrom, lookat, vup, vfov, aspect_ratio, aperture,
dist_to_focus, time0, time1)
return world_bvh, cam
def scan_line(j: int, background: Color, world: BVHNode, cam: Camera,
image_width: int, image_height: int, samples_per_pixel: int,
max_depth: int) -> Img:
img = Img(image_width, 1)
for i in range(image_width):
pixel_color = Color(0, 0, 0)
for s in range(samples_per_pixel):
u: float = (i + random_float()) / (image_width - 1)
v: float = (j + random_float()) / (image_height - 1)
r: Ray = cam.get_ray(u, v)
pixel_color += ray_color(r, background, world, max_depth)
img.write_pixel(i, 0, pixel_color, samples_per_pixel)
print(f"Scanlines remaining: {j} ", end="\r")
return img
def hit(self, r: Ray, t_min: float, t_max: float) -> Optional[HitRecord]:
rec1 = self.boundary.hit(r, -np.inf, np.inf)
if rec1 is None:
return None
rec2 = self.boundary.hit(r, rec1.t + 0.0001, np.inf)
if rec2 is None:
return None
if rec1.t < t_min:
rec1.t = t_min
if rec1.t < 0:
rec1.t = 0
if rec2.t > t_max:
rec2.t = t_max
if rec1.t >= rec2.t:
return None
ray_length = r.direction().length()
distance_inside_boundary = (rec2.t - rec1.t) * ray_length
hit_distance = self.neg_inv_density * np.log(random_float())
if hit_distance > distance_inside_boundary:
return None
t = rec1.t + hit_distance / ray_length
p = r.at(t)
rec = HitRecord(p, t, self.phase_function)
rec.normal = Vec3(1, 0, 0)
rec.front_face = True
return rec
def scatter(self, r_in: Ray, rec: HitRecord) \
-> Optional[Tuple[Ray, Color]]:
if rec.front_face:
etai_over_etat = 1 / self.ref_idx
else:
etai_over_etat = self.ref_idx
unit_direction: Vec3 = r_in.direction().unit_vector()
cos_theta: float = min(-unit_direction @ rec.normal, 1)
sin_theta: float = np.sqrt(1 - cos_theta**2)
reflect_prob: float = self.schlick(cos_theta, etai_over_etat)
if etai_over_etat * sin_theta > 1 or random_float() < reflect_prob:
# total internal reflection
reflected: Vec3 = unit_direction.reflect(rec.normal)
scattered = Ray(rec.p, reflected)
else:
# refraction
refracted: Vec3 = unit_direction.refract(
rec.normal, etai_over_etat
)
scattered = Ray(rec.p, refracted)
attenuation = Color(1, 1, 1)
return scattered, attenuation
def random_in_unit_sphere() -> Vec3:
"""
This method is modified from:
https://karthikkaranth.me/blog/generating-random-points-in-a-sphere/#better-choice-of-spherical-coordinates
"""
u = random_float()
v = random_float()
theta = u * 2 * cp.pi
phi = cp.arccos(2 * v - 1)
r = cp.cbrt(random_float())
sinTheta = cp.sin(theta)
cosTheta = cp.cos(theta)
sinPhi = cp.sin(phi)
cosPhi = cp.cos(phi)
x = r * sinPhi * cosTheta
y = r * sinPhi * sinTheta
z = r * cosPhi
return Vec3(x, y, z)
def get_ray(self, s: float, t: float) -> Ray:
rd: Vec3 = Vec3.random_in_unit_disk() * self.lens_radius
offset: Vec3 = self.u * rd.x() + self.v * rd.y()
return Ray(
self.origin + offset,
(self.lower_left_corner
+ self.horizontal*s + self.vertical*t
- self.origin - offset),
random_float(self.time0, self.time1)
)
def random_scene() -> HittableList:
world = HittableList()
ground_material = Lambertian(Color(0.5, 0.5, 0.5), 1)
world.add(Sphere(Point3(0, -1000, 0), 1000, ground_material))
sphere_material_glass = Dielectric(1.5, 2)
for a in range(-11, 11):
for b in range(-11, 11):
choose_mat = random_float()
center = Point3(a + 0.9 * random_float(), 0.2,
b + 0.9 * random_float())
if (center - Vec3(4, 0.2, 0)).length() > 0.9:
idx = (a * 22 + b) + (11 * 22 + 11) + 6
if choose_mat < 0.6:
# Diffuse
albedo = Color.random() * Color.random()
sphere_material_diffuse = Lambertian(albedo, idx)
world.add(Sphere(center, 0.2, sphere_material_diffuse))
elif choose_mat < 0.8:
# Metal
albedo = Color.random(0.5, 1)
fuzz = random_float(0, 0.5)
sphere_material_metal = Metal(albedo, fuzz, idx)
world.add(Sphere(center, 0.2, sphere_material_metal))
else:
# Glass
world.add(Sphere(center, 0.2, sphere_material_glass))
material_1 = Dielectric(1.5, 3)
world.add(Sphere(Point3(0, 1, 0), 1, material_1))
material_2 = Lambertian(Color(0.4, 0.2, 0.1), 4)
world.add(Sphere(Point3(-4, 1, 0), 1, material_2))
material_3 = Metal(Color(0.7, 0.6, 0.5), 0, 5)
world.add(Sphere(Point3(4, 1, 0), 1, material_3))
return world
def random_in_unit_disk():
while True:
p = Vec3(random_float(-1, 1), random_float(-1, 1), 0)
if p.length_squared() >= 1:
continue
return p
def random_unit_vector() -> Vec3:
a: float = random_float(0, 2 * np.pi)
z: float = random_float(-1, 1)
r: float = np.sqrt(1 - z**2)
return Vec3(r * np.cos(a), r * np.sin(a), z)
def final_scene(aspect_ratio: float, time0: float, time1: float) \
-> Tuple[BVHNode, Camera]:
world = HittableList()
# Ground
boxes1 = HittableList()
ground = Lambertian(SolidColor(0.48, 0.83, 0.53))
boxes_per_side = 20
for i in range(boxes_per_side):
for j in range(boxes_per_side):
w = 100
x0 = -1000 + i * w
z0 = -1000 + j * w
y0 = 0
x1 = x0 + w
y1 = random_float(1, 101)
z1 = z0 + w
boxes1.add(Box(Point3(x0, y0, x0), Point3(x1, y1, z1), ground))
world.add(BVHNode(boxes1.objects, time0, time1))
# Light
light = DiffuseLight(SolidColor(7, 7, 7))
world.add(XZRect(123, 423, 147, 412, 554, light))
# Moving sphere
center1 = Point3(400, 400, 200)
center2 = center1 + Vec3(30, 0, 0)
moving_sphere_material = Lambertian(SolidColor(0.7, 0.3, 0.1))
world.add(MovingSphere(center1, center2, 0, 1, 50, moving_sphere_material))
# Dielectric & metal balls
world.add(Sphere(Point3(260, 150, 45), 50, Dielectric(1.5)))
world.add(
Sphere(Point3(0, 150, 145), 50, Metal(Color(0.8, 0.8, 0.9), 10.0)))
# The subsurface reflection sphere
boundary = Sphere(Point3(360, 150, 145), 70, Dielectric(1.5))
world.add(boundary)
world.add(ConstantMedium(boundary, 0.2, SolidColor(0.2, 0.4, 0.9)))
# Big thin mist
mist = Sphere(Point3(0, 0, 0), 5000, Dielectric(1.5))
world.add(ConstantMedium(mist, 0.0001, SolidColor(1, 1, 1)))
# Earth and marble ball
emat = Lambertian(ImageTexture("earthmap.jpg"))
world.add(Sphere(Point3(400, 200, 400), 100, emat))
pertext = NoiseTexture(0.1)
world.add(Sphere(Point3(220, 280, 300), 80, Lambertian(pertext)))
# Foam
boxes2 = HittableList()
white = Lambertian(SolidColor(0.73, 0.73, 0.73))
ns = 1000
for j in range(ns):
boxes2.add(Sphere(Point3.random(0, 165), 10, white))
world.add(
Translate(RotateY(BVHNode(boxes2.objects, time0, time1), 15),
Vec3(-100, 270, 395)))
world_bvh = BVHNode(world.objects, time0, time1)
lookfrom = Point3(478, 278, -600)
lookat = Point3(278, 278, 0)
vup = Vec3(0, 1, 0)
vfov = 40
dist_to_focus: float = 10
aperture: float = 0
cam = Camera(lookfrom, lookat, vup, vfov, aspect_ratio, aperture,
dist_to_focus, time0, time1)
return world_bvh, cam
