def scatter(self, r_in: Ray, rec: hit_record):
reflected: np.ndarray = reflect(r_in.direction(), rec.normal)
attenuation = np.array((1, 1, 1), float)
if np.dot(r_in.direction(), rec.normal) > 0:
outward_normal = -rec.normal
ni_over_nt = self.ref_idx
cosine = self.ref_idx * np.dot(r_in.direction(),
rec.normal) / np.linalg.norm(
r_in.direction())
else:
outward_normal = rec.normal
ni_over_nt = 1.0 / self.ref_idx
cosine = float(-np.dot(r_in.direction(), rec.normal) /
np.linalg.norm(r_in.direction()))
has_refracted, refracted = refract(r_in.direction(), outward_normal,
ni_over_nt)
if has_refracted:
reflect_prob = schlick(cosine, self.ref_idx)
else:
reflect_prob = 1
if random() < reflect_prob:
scattered = Ray(rec.p, reflected, r_in.time())
else:
scattered = Ray(rec.p, refracted, r_in.time())
return True, attenuation, scattered
def hit(self, r: Ray, t_min: float, t_max: float):
oc = r.origin() - self.center(r.time())
a = np.dot(r.direction(), r.direction())
b = np.dot(oc, r.direction())
c = np.dot(oc, oc) - self.radius * self.radius
discriminant = b * b - a * c
if discriminant > 0:
temp = (-b - sqrt(b * b - a * c)) / a
if (temp < t_max) and (temp > t_min):
t = float(temp)
p = r.point_at_parameter(t)
normal = (p - self.center(r.time())) / self.radius
u, v = get_shpere_uv((p - self.center(r.time())) / self.radius)
rec = hit_record(t, p, normal, self.material, u, v)
return True, rec
temp = (-b + sqrt(b * b - a * c)) / a
if (temp < t_max) and (temp > t_min):
t = float(temp)
p = r.point_at_parameter(t)
normal = (p - self.center(r.time())) / self.radius
u, v = get_shpere_uv((p - self.center(r.time())) / self.radius)
rec = hit_record(t, p, normal, self.material, u, v)
return True, rec
return False, None
def scatter(self, r_in: Ray, rec: hit_record):
unit_direction = r_in.direction() / np.linalg.norm(r_in.direction())
reflected: np.ndarray = reflect(unit_direction, rec.normal)
scattered = Ray(rec.p, reflected + self.fuzz * random_in_unit_sphere(),
r_in.time())
attenuation = self.albedo
return (np.dot(scattered.direction(), rec.normal) >
0), attenuation, scattered
def scatter(self, r_in: Ray, rec: hit_record):
target: np.ndarray = rec.p + rec.normal + random_in_unit_sphere()
scattered = Ray(rec.p, target - rec.p, r_in.time())
attenuation = self.albedo.value(rec.u, rec.v, rec.p)
# attenuation = np.array((0.5, 0.5, 0.5))
# print("rin: " + str(r_in))
if type(self.albedo) == noise_texture:
print("attenuation: " + str(attenuation))
print("scatter: " + str(scattered))
return True, attenuation, scattered
