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 hit(self,r,t_min,t_max):
rec = None
oc = r.origin - self.center(r.time)
a = Vec3.dot(r.direction,r.direction)
b = Vec3.dot(oc,r.direction)
c = Vec3.dot(oc,oc) - (self.radius*self.radius)
discriminant = (b*b) - (a*c)
if discriminant > 0:
rec = {}
temp = (-b - sqrt(discriminant)) / a
if t_min < temp < t_max:
rec["t"] = temp
rec["p"] = r.point_at_parameter(rec["t"])
rec["u"],rec["v"] =getSphereUv((rec["p"] - self.center) / self.radius)
rec["normal"] = (rec["p"] - self.center(r.time)) / self.radius
rec["material"] = self.material
return rec
temp = (-b + sqrt(discriminant)) / a
if t_min < temp < t_max:
rec["t"] = temp
rec["p"] = r.point_at_parameter(rec["t"])
rec["u"],rec["v"] =getSphereUv((rec["p"] - self.center) / self.radius)
rec["normal"] = (rec["p"] - self.center(r.time)) / self.radius
rec["material"] = self.material
return rec
return None
def hit_sphere(center,radius,r): oc = r.origin -center a = Vec3.dot(r.direction,r.direction) b = 2.0 * Vec3.dot(oc,r.direction) c = Vec3.dot(oc,oc) - radius * radius discriminant = b*b - 4*a*c return discriminant > 0
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
def hit(self,r,t_min,t_max):
rec = None
oc = r.origin - self.center
a = Vec3.dot(r.direction,r.direction)
b = Vec3.dot(oc,r.direction)
c = Vec3.dot(oc,oc) - (self.radius*self.radius)
discriminant = (b*b) - (a*c)
if discriminant > 0:
rec = {}
temp = (-b - sqrt(discriminant)) / a
if t_min < temp < t_max:
rec["t"] = temp
rec["p"] = r.point_at_parameter(rec["t"])
rec["normal"] = (rec["p"] - self.center) / self.radius
return rec
temp = (-b + sqrt(discriminant)) / a
if t_min < temp < t_max:
rec["t"] = temp
rec["p"] = r.point_at_parameter(rec["t"])
rec["normal"] = (rec["p"] - self.center) / self.radius
return rec
return None
def trilinear_interp(c,u,v,w):
uu = u*u*(3-2*u)
vv = v*v*(3-2*v)
ww = w*w*(3-2*w)
accum = 0.0
for i in range(2):
for j in range(2):
for k in range(2):
weight_v= Vec3(u-i,v-j,w-k)
accum += (((i*uu) + (1-i)*(1-uu)) *
((j*vv) + (1-j)*(1-vv)) *
((k*ww) + (1-k)*(1-ww)) * Vec3.dot(c[i][j][k],weight_v))
return accum
def createFromVectors(v1, v2):
""" Function createFromVectors expects two 3d vectors. Quat has the Sofa format i.e (x,y,z,w).
Examples:
>>> q = Quat.createFromVectors([1,0,0],[0,1,0])
>>> print(q)
[0.,0.,0.707,0.707]
"""
from quat import Quat
from vec3 import Vec3
from math import sqrt
q = Quat()
v = Vec3.cross(v1, v2)
q[0:3] = v
q[3] = sqrt((Vec3(v1).getNorm()**2) *
(Vec3(v2).getNorm()**2)) + Vec3.dot(v1, v2)
q.normalize()
return q
def random_in_unit_sphere(cls):
while True:
p = 2.0 * Vec3(random(), random(), random()) - Vec3(1, 1, 1)
if Vec3.dot(p, p) < 1.0:
return p
def get_closest_point_to(self, point):
n = self.get_normal()
return point - (Vec3.dot(Vec3.from_to(self.origin, point), n)*n)
def random_in_unit_disk():
while True:
p = 2.0 * Vec3(random(),random(),0) -Vec3(1,1,0)
if Vec3.dot(p,p) < 1.0:
return p
def random_in_unit_sphere(cls):
while True:
p = 2.0*Vec3(random(),random(),random()) - Vec3(1,1,1)
if Vec3.dot(p,p) < 1.0:
return p
def reflect(v_in: Vec3, normal: Vec3):
return v_in - 2*v_in.dot(normal)*normal
def get_closest_point_to(self, point):
l = self.direction.get_unit()
return self.origin + (Vec3.dot(Vec3.from_to(self.origin, point), l)*l)
def random_in_unit_disk():
while True:
p = 2.0 * Vec3(random(), random(), 0) - Vec3(1, 1, 0)
if Vec3.dot(p, p) < 1.0:
return p
