def local_intersect(self, local_ray):
xtmin, xtmax = self.check_axis(local_ray.origin[0],
local_ray.direction[0])
ytmin, ytmax = self.check_axis(local_ray.origin[1],
local_ray.direction[1])
ztmin, ztmax = self.check_axis(local_ray.origin[2],
local_ray.direction[2])
tmin = max(xtmin, ytmin, ztmin)
tmax = min(xtmax, ytmax, ztmax)
# ray misses cube?
if tmin > tmax:
return []
return [Intersection(tmin, self), Intersection(tmax, self)]
def intersect_caps(self, ray, xs):
# caps only matter if the cylinder is closed, and might possibly be
# intersected by the ray.
if not self.closed or abs(ray.direction[1]) < self.EPSILON:
return []
# check for an intersection with the lower end cap by intersecting
# the ray with the plane at y=cyl.minimum
t = (self.minimum - ray.origin[1]) / ray.direction[1]
if self.check_cap(ray, t, self.minimum):
xs.append(Intersection(t, self))
# check for an intersection with the upper end cap by intersecting
# the ray with the plane at y=cyl.maximum
t = (self.maximum - ray.origin[1]) / ray.direction[1]
if self.check_cap(ray, t, self.maximum):
xs.append(Intersection(t, self))
def local_intersect(self, local_ray):
a = local_ray.direction[0]**2 - \
local_ray.direction[1]**2 + \
local_ray.direction[2]**2
b = 2 * local_ray.origin[0] * local_ray.direction[0] - \
2 * local_ray.origin[1] * local_ray.direction[1] + \
2 * local_ray.origin[2] * local_ray.direction[2]
if abs(a) < self.EPSILON and abs(b) < self.EPSILON:
return []
c = local_ray.origin[0]**2 - \
local_ray.origin[1]**2 + \
local_ray.origin[2]**2
if abs(a) < self.EPSILON:
t = -c / (2 * b)
xs = [Intersection(t, self)]
self.intersect_caps(local_ray, xs)
return xs
discriminant = b**2 - 4 * a * c
# ray does not intersect the cone
if discriminant < 0:
return []
t0 = (-b - sqrt(discriminant)) / (2 * a)
t1 = (-b + sqrt(discriminant)) / (2 * a)
if t0 > t1:
t0, t1 = t1, t0
xs = []
y0 = local_ray.origin[1] + t0 * local_ray.direction[1]
if self.minimum < y0 < self.maximum:
xs.append(Intersection(t0, self))
y1 = local_ray.origin[1] + t1 * local_ray.direction[1]
if self.minimum < y1 < self.maximum:
xs.append(Intersection(t1, self))
self.intersect_caps(local_ray, xs)
return xs
def local_intersect(self, local_ray):
sphere_to_ray = subtract(local_ray.origin, point(0, 0, 0))
a = dot(local_ray.direction, local_ray.direction)
b = 2 * dot(local_ray.direction, sphere_to_ray)
c = dot(sphere_to_ray, sphere_to_ray) - 1
discriminant = b**2 - 4 * a * c
if discriminant < 0:
return []
t1 = (-b - sqrt(discriminant)) / (2 * a)
t2 = (-b + sqrt(discriminant)) / (2 * a)
i1 = Intersection(t1, self)
i2 = Intersection(t2, self)
return [i1, i2]
def local_intersect(self, local_ray):
a = local_ray.direction[0]**2 + local_ray.direction[2]**2
# ray is parallel to the y axis?
if abs(a) < self.EPSILON:
xs = []
self.intersect_caps(local_ray, xs)
return xs
b = 2 * local_ray.origin[0] * local_ray.direction[0] + \
2 * local_ray.origin[2] * local_ray.direction[2]
c = local_ray.origin[0]**2 + local_ray.origin[2]**2 - 1
discriminant = b**2 - 4 * a * c
# ray does not intersect the cylinder
if discriminant < 0:
return []
t0 = (-b - sqrt(discriminant)) / (2 * a)
t1 = (-b + sqrt(discriminant)) / (2 * a)
if t0 > t1:
t0, t1 = t1, t0
xs = []
y0 = local_ray.origin[1] + t0 * local_ray.direction[1]
if self.minimum < y0 < self.maximum:
xs.append(Intersection(t0, self))
y1 = local_ray.origin[1] + t1 * local_ray.direction[1]
if self.minimum < y1 < self.maximum:
xs.append(Intersection(t1, self))
self.intersect_caps(local_ray, xs)
return xs
def local_intersect(self, local_ray):
dir_cross_e2 = cross(local_ray.direction, self.e2)
determinant = dot(self.e1, dir_cross_e2)
if abs(determinant) < self.EPSILON:
return []
f = 1.0 / determinant
p1_to_origin = subtract(local_ray.origin, self.p1)
u = f * dot(p1_to_origin, dir_cross_e2)
if u < 0.0 or u > 1.0:
return []
origin_cross_e1 = cross(p1_to_origin, self.e1)
v = f * dot(local_ray.direction, origin_cross_e1)
if v < 0.0 or (u + v) > 1.0:
return []
t = f * dot(self.e2, origin_cross_e1)
if self.smoothed:
return [Intersection(t, self, u, v)]
return [Intersection(t, self)]
def create_intersections_from_string(context, intersections):
result = []
for part in intersections.split(','):
part = part.strip()
if ':' in part:
(pos, obj) = part.split(':')
if pos == 'sqrt(2)/2':
pos_num = sqrt(2) / 2
elif pos == '-sqrt(2)/2':
pos_num = -sqrt(2) / 2
elif pos == 'sqrt(2)':
pos_num = sqrt(2)
else:
pos_num = float(pos)
var = getattr(context, obj, None)
result.append(Intersection(pos_num, var))
else:
var = getattr(context, part, None)
result.append(var)
return result
def step_create_intersection_i_with_uv(context, t, obj_name, u, v):
obj = getattr(context, obj_name, None)
context.i = Intersection(t, obj, u, v)
def step_impl(context, t):
context.i = Intersection(t, context.s)
def step_determine_intersection_i1_at_sqrt_2_for_p(context):
context.i1 = Intersection(sqrt(2), context.p)
def local_intersect(self, local_ray):
if abs(local_ray.direction[1]) < self.EPSILON:
return []
t = -local_ray.origin[1] / local_ray.direction[1]
return [Intersection(t, self)]
