def __init__(self,
aspect,
vfov,
aperture,
focus_dist,
lookfrom,
lookat,
vup=Vec(0, 1, 0)):
self.lens_radius = aperture / 2
theta = vfov * pi / 180
half_height = tan(theta / 2)
half_width = aspect * half_height
self.origin = lookfrom
w = Vec.unit_vector(lookfrom - lookat)
u = Vec.unit_vector(Vec.cross(vup, w))
v = Vec.cross(w, u)
self.lower_left = self.origin - half_width * focus_dist * u - half_height * focus_dist * v - focus_dist * w
self.horizontal = 2 * half_width * focus_dist * u
self.vertical = 2 * half_height * focus_dist * v
self.u = u
self.v = v
def scatter(self, r_in, hit_rec, attenuation, r_scattered):
reflected = Vec.reflect_mv(Vec.unit_vector(r_in.direction), hit_rec.n)
r_scattered.A = hit_rec.p
r_scattered.B = Sphere.random_in_unit_sphere().mul(
self.fuzz).add(reflected)
attenuation.x = self.albedo.x
attenuation.y = self.albedo.y
attenuation.z = self.albedo.z
return Vec.dot(r_scattered.direction, hit_rec.n) > 0
def refract(v, n, ior, refracted):
uv = Vec.unit_vector(v)
dt = Vec.dot(uv, n)
disc = 1 - ior * ior * (1 - dt * dt)
if disc > 0:
sqrt_disc = sqrt(disc)
refracted.x = ior * (uv.x - n.x * dt) - n.x * sqrt_disc
refracted.y = ior * (uv.y - n.y * dt) - n.y * sqrt_disc
refracted.z = ior * (uv.z - n.z * dt) - n.z * sqrt_disc
return True
else:
return False
def color(ray, world, depth):
hit_rec = HitRecord()
if world.hit(ray, 0.001, float('inf'), hit_rec):
scattered = Ray()
attenuation = Vec()
hit_mat = hit_rec.mat
if depth < MAXIMUM_DEPTH and hit_mat.scatter(ray, hit_rec, attenuation,
scattered):
return color(scattered, world, depth + 1).vec_mul(attenuation)
else:
return Vec()
else:
unit_dir = Vec.unit_vector(ray.direction)
t = 0.5 * (unit_dir.y + 1)
ti = 1 - t
return Vec(ti * BG_COL_A.x + t * BG_COL_B.x,
ti * BG_COL_A.y + t * BG_COL_B.y,
ti * BG_COL_A.z + t * BG_COL_B.z)
