def intersect(self, r, t_min, t_max):
oc = r.origin - self.center
a = r.squared_length()
half_b = u.dot(oc, r.directions)
c = u.dot(oc, oc) - self.radius * self.radius
discriminant = half_b * half_b - a * c
sqrtd = torch.sqrt(torch.maximum(torch.zeros_like(discriminant), discriminant))
h0 = (-half_b - sqrtd) / a
h1 = (-half_b + sqrtd) / a
# TODO: There should be t_min there. But let's wait for that
h = torch.where((h0 > 0.1) & (h0 < h1), h0, h1)
pred = (discriminant > 0) & (h > 0)
root = torch.where(pred, h, t_max)
return root
def intersect_straight(self, r, t_max):
oc = r.pos - self.center
a = u.dot(r.vel, r.vel) # This will be one always actually
half_b = u.dot(oc, r.vel)
c = u.dot(oc, oc) - self.radius * self.radius
discriminant = half_b * half_b - a * c
sqrtd = torch.sqrt(
torch.maximum(torch.zeros_like(discriminant), discriminant))
h0 = (-half_b - sqrtd) / a
h1 = (-half_b + sqrtd) / a
h = torch.where((h0 > 0.1) & (h0 < h1), h0, h1)
pred = (discriminant > 0) & (h > 0)
root = torch.where(pred, h, t_max)
return root
def hit(self, r, distance, color, world):
intersections = distance < self.radius
if intersections.any():
color = color.detach().clone()
outward_normal = (r.pos - self.center) / self.radius
scattered_pos, scattered_vel = self.material.scatter(
r, outward_normal)
r.update(intersections, scattered_pos, scattered_vel)
for light in world.lights:
r_shadow = Rays.from_shadow(r.pos, light - r.pos, r.dev)
distances, nearest_distance = world.hit_shadows(r_shadow)
see_light = distances[world.objects.index(
self)] == nearest_distance
lv = torch.clamp(u.dot(outward_normal, r_shadow.vel),
min=0) # Taking the maximum
color += self.material.albedo * see_light * lv
return r, color, intersections
def _reflect(v, n):
return v - 2 * dot(v, n) * n
def intersect(self, r):
oc = r.pos - self.center
distances = torch.sqrt(u.dot(oc, oc))
return distances