def scatter(self, r_in, rec):
outward_normal = Vec3()
reflected = Vec3.reflect(r_in.direction, rec["normal"])
ni_over_nt = 0.0
attenuation = Vec3(1.0, 1.0, 1.0)
cosine = 0.0
if Vec3.dot(r_in.direction, rec["normal"]) > 0:
outward_normal = -rec["normal"]
ni_over_nt = self.ref_idx
cosine = self.ref_idx * Vec3.dot(
r_in.direction, rec["normal"]) / r_in.direction.length()
else:
outward_normal = rec["normal"]
ni_over_nt = 1.0 / self.ref_idx
cosine = -Vec3.dot(r_in.direction,
rec["normal"]) / r_in.direction.length()
scattered = Ray()
reflect_prob = 0.0
refracted = Vec3.refract(r_in.direction, outward_normal, ni_over_nt)
if refracted is not None:
reflect_prob = schlick(cosine, self.ref_idx)
else:
reflect_prob = 1.0
if random() < reflect_prob:
scattered = Ray(rec["p"], reflected)
else:
scattered = Ray(rec["p"], refracted)
return attenuation, scattered
def scatter(self, r_in, rec):
outward_normal = Vec3()
reflected = Vec3.reflect(r_in.direction,rec["normal"])
ni_over_nt = 0.0
attenuation = Vec3(1.0,1.0,1.0)
cosine = 0.0
if Vec3.dot(r_in.direction,rec["normal"]) > 0:
outward_normal = -rec["normal"]
ni_over_nt = self.ref_idx
cosine = self.ref_idx * Vec3.dot(r_in.direction,rec["normal"])/ r_in.direction.length()
else:
outward_normal = rec["normal"]
ni_over_nt = 1.0 / self.ref_idx
cosine = -Vec3.dot(r_in.direction,rec["normal"])/ r_in.direction.length()
scattered = Ray()
reflect_prob = 0.0
refracted = Vec3.refract(r_in.direction,outward_normal,ni_over_nt)
if refracted is not None:
reflect_prob = schlick(cosine,self.ref_idx)
else:
reflect_prob = 1.0
if random() < reflect_prob:
scattered = Ray(rec["p"],reflected)
else:
scattered = Ray(rec["p"],refracted)
return attenuation, scattered
def scatter(self, r_in,rec):
reflected = Vec3.reflect(Vec3.unit_vector(r_in.direction),rec["normal"])
scattered = Ray(rec["p"],reflected + self.fuzz * Material.random_in_unit_sphere())
attenuation = self.albedo
if Vec3.dot(scattered.direction,rec["normal"]) > 0:
return attenuation,scattered
else:
return None,None
def scatter(self, r_in, rec):
reflected = Vec3.reflect(Vec3.unit_vector(r_in.direction),
rec["normal"])
scattered = Ray(
rec["p"], reflected + self.fuzz * Material.random_in_unit_sphere())
attenuation = self.albedo
if Vec3.dot(scattered.direction, rec["normal"]) > 0:
return attenuation, scattered
else:
return None, None