def make_ray(self, i, j):
# was having difficulty making a good mass-ray-generation routine, settled on on-demand
# speed is fine and it'll be good for future adaptive sampling stuff
n1 = np.random.random()
n2 = np.random.random()
origin = self.origin + self.dx_dp * (j + n1) + self.dy_dp * (i + n2)
ray = Ray(origin, unit(self.focal_point - origin))
ray.i = i
ray.j = j
return ray
def extend_path(path: Path, root: Box):
triangle, t = traverse_bvh(root, path.ray)
if triangle is not None:
# generate new ray
new_origin = path.ray.origin + path.ray.direction * t
new_direction = BRDF_sample(triangle.material, -1 * path.ray.direction, triangle.normal, path.direction)
new_ray = Ray(new_origin, new_direction)
new_ray.normal = triangle.normal
new_ray.material = triangle.material
new_ray.local_color = triangle.color
if triangle.emitter:
path.hit_light = True
path_push(path, new_ray)
# if path_health_check(path):
return True
else:
return False
def extend_path(path: Path, boxes, triangles):
triangle, t = traverse_bvh(boxes, triangles, path.ray)
if triangle is not None:
# generate new ray
new_origin = path.ray.origin + path.ray.direction * t
new_direction = brdf_sample(triangle.material, -1 * path.ray.direction,
triangle.normal, path.direction)
new_ray = Ray(new_origin, new_direction)
new_ray.normal = triangle.normal
new_ray.material = triangle.material
new_ray.local_color = triangle.color
if triangle.emitter:
path.hit_light = True
path_push(path, new_ray)
return True
else:
return False
def _trace_ray(self, ray, calc_color, tol, tracing_depth):
"""
:param ray: object of type Ray
:param calc_color: function, which takes Hit object as parameter and returns color of object in this point
:return: result of execution calc_color function
"""
min_dist = 1e8
min_hit = None
for obj in self.scene.objects:
hit = obj.intersect(ray, tol)
if hit is None:
continue
dist = hit.distance()
if dist < min_dist:
min_dist = dist
min_hit = hit
obj_color = calc_color(min_hit)
res_shading = np.array([0.0, 0.0, 0.0])
if min_hit is not None:
# Tracing shadow rays
for light in self.scene.lights:
shadow_ray = Ray(min_hit.point, light.origin - min_hit.point)
shadow_hit = self._trace_shadow_ray(shadow_ray, tol)
if shadow_hit is None:
res_shading += light.get_intensity(shadow_ray) * obj_color * max(0, np.dot(min_hit.normal, shadow_ray.direction))
# Tracing reflection ray
if tracing_depth > 0:
reflection_ray_dir = ray.direction - 2.0 * (np.dot(ray.direction, min_hit.normal)) * min_hit.normal
reflection_ray = Ray(min_hit.point, reflection_ray_dir)
reflection_shading = self._trace_ray(reflection_ray, calc_color, tol, tracing_depth - 1)
res_shading += REFLECTION_COEF * reflection_shading
return res_shading
def isValidMove(self, A, B):
# get the direction of the movement ray
D = B - A
dist = LA.norm(D)
# trace a ray to get the hit record towards scene objects
ray = Ray(A, D / dist)
d, hr = self.trace(ray)
# we can move if we don't hit a wall
return dist < d
def path_push(path: Path, ray: Ray):
# update stuff appropriately
if path.direction == Direction.STORAGE.value:
# don't change anything, this is just a stack. this reduces wasted calculation and preserves first-vertex values
pass
elif path.ray is None:
# this shouldn't come up
pass
else:
G = geometry_term(path.ray, ray)
path.ray.direction = unit(ray.origin - path.ray.origin)
if path.ray.prev is None:
# pushing onto stack of 1, just propagate p and color (?)
ray.color = path.ray.color * G
ray.p = path.ray.p * G
else:
# pushing onto stack of 2 or more, do some work
brdf = BRDF_function(path.ray.material, -1 * path.ray.prev.direction, path.ray.normal, path.ray.direction,
path.direction)
ray.color = path.ray.local_color * path.ray.color * brdf * G
ray.p = path.ray.p * G * BRDF_pdf(path.ray.material, -1 * path.ray.prev.direction, path.ray.normal, path.ray.direction,
path.direction)
ray.bounces = path.ray.bounces + 1
# store new ray
ray.prev = path.ray
path.ray = ray
def get_ray(self, point):
"""
:param point: point of type tuple (x: float, y: float), where -1 <= x, y <= 1
:return:
"""
fov_x, fov_y = self.fov_angle
d = 1 / np.tan(fov_x / 2)
x, y = point
u, v, w = self.direction
aspect = fov_y / fov_x
dir = x * u + aspect * y * v + d * w
normalized_direction = dir / np.sqrt(np.dot(dir, dir))
return Ray(self.origin, normalized_direction)
def generate_light_ray(box: Box):
light_index = np.random.randint(0, len(box.lights))
light = box.lights[light_index]
light_origin = light.sample_surface()
x, y, z = local_orthonormal_system(light.normal)
light_direction = random_hemisphere_uniform_weighted(x, y, z)
ray = Ray(light_origin, light_direction)
ray.color = light.color
ray.local_color = light.color
ray.normal = light.normal
ray.p = 1 / (2 * np.pi * light.surface_area)
return ray
def visibility_test(boxes, triangles, ray_a: Ray, ray_b: Ray):
delta = ray_b.origin - ray_a.origin
least_t = np.linalg.norm(delta)
direction = delta / least_t
if np.dot(ray_a.normal, direction) <= 0 or np.dot(ray_b.normal, -1 * direction) <= 0:
return False
test_ray = Ray(ray_a.origin, direction)
stack = [boxes[0]]
while stack:
box = stack.pop()
if box.right == 0:
if bvh_hit_inner(test_ray, box, least_t):
stack.append(boxes[box.left])
stack.append(boxes[box.left + 1])
else:
if visibility_hit_leaf(test_ray, box, triangles[box.left:box.right], least_t):
return False
return True
def visibility_test(root: Box, ray_a: Ray, ray_b: Ray):
delta = ray_b.origin - ray_a.origin
least_t = np.linalg.norm(delta)
direction = delta / least_t
if np.dot(ray_a.normal, direction) <= 0 or np.dot(ray_b.normal, -1 * direction) <= 0:
return False
test_ray = Ray(ray_a.origin, direction)
stack = BoxStack()
stack.push(root)
while stack.size:
box = stack.pop()
if box.left is not None and box.right is not None:
if bvh_hit_inner(test_ray, box, least_t):
stack.push(box.left)
stack.push(box.right)
else:
hit, t = bvh_hit_leaf(test_ray, box, least_t)
if hit is not None and t < least_t:
return False
return True
def generate_light_ray(emitters):
light = emitters[np.random.randint(0, len(emitters))]
light_origin = light.sample_surface()
x, y, z = local_orthonormal_system(light.normal)
light_direction = random_hemisphere_uniform_weighted(x, y, z)
ray = Ray(light_origin, light_direction)
ray.color = light.color
ray.local_color = light.color
ray.normal = light.normal
# this seems made up
ray.p = 1 / (2 * np.pi * light.surface_area)
return ray
def path_push(path: Path, ray: Ray):
# update stuff appropriately
G = geometry_term(path.ray, ray)
path.ray.direction = unit(ray.origin - path.ray.origin)
if path.ray.prev is None:
# pushing onto stack of 1, just propagate p and color (?)
ray.color = path.ray.color * G
ray.p = path.ray.p * G
else:
# pushing onto stack of 2 or more, do some work
brdf = brdf_function(path.ray.material, -1 * path.ray.prev.direction,
path.ray.normal, path.ray.direction,
path.direction)
ray.color = path.ray.local_color * path.ray.color * brdf * G
ray.p = path.ray.p * G * brdf_pdf(
path.ray.material, -1 * path.ray.prev.direction, path.ray.normal,
path.ray.direction, path.direction)
ray.bounces = path.ray.bounces + 1
# store new ray
ray.prev = path.ray
path.ray = ray
def ray_that_misses():
return Ray(ONES * 5, UNIT_Y)
def ray_inside_box():
return Ray(point(0.5, 0.5, 0.5), UNIT_Z)
def ray_that_hits():
# hits object in center
return Ray(point(0.2, 0.2, 5), -1 * UNIT_Z)
def ray_that_barely_hits():
# hits object at origin
return Ray(UNIT_Z * 5, -1 * UNIT_Z)
def extend_path(path, root, path_direction):
for i in range(MAX_BOUNCES):
ray = path[-1]
triangle, t = traverse_bvh(root, ray)
if triangle is not None:
# generate new ray
# new vectors
origin = ray.origin + ray.direction * t
direction = BRDF_sample(triangle.material, -1 * ray.direction,
triangle.normal, path_direction)
new_ray = Ray(origin, direction)
# store info from triangle
new_ray.normal = triangle.normal
new_ray.material = triangle.material
new_ray.local_color = triangle.color
if path_direction == Direction.FROM_CAMERA.value and triangle.emitter:
new_ray.hit_light = True
# probability, weight, and color updates
G = geometry_term(ray, new_ray)
if i == 0:
# only need to multiply by G because p of this direction is already stored at creation
new_ray.p = ray.p * G
# same deal, "brdf" of source is already in ray.color
new_ray.color = ray.color * G
new_ray.G = G
else:
# so the idea here is that each vertex has information about everything up to it but not including it,
# because we can't be sure of anything about the final bounce until we know the joining vertex
bounce_p = BRDF_pdf(ray.material, -1 * path[-2].direction,
ray.normal, ray.direction, path_direction)
new_ray.p = ray.p * G * bounce_p
new_ray.color = ray.color * ray.local_color * G * BRDF_function(
ray.material, -1 * path[-2].direction, ray.normal,
ray.direction, path_direction)
new_ray.G = G
ray.local_p = bounce_p
path.append(new_ray)
else:
break