def test_close_to_zero(self):
# Value is considered zero if abs(value) < EPS_ZERO
zero = 0.0
assert close_to_zero(zero) == True
assert close_to_zero(zero + 0.9 * EPS_ZERO) == True
assert close_to_zero(zero - 0.9 * EPS_ZERO) == True
assert close_to_zero(zero + EPS_ZERO) == False
assert close_to_zero(zero - EPS_ZERO) == False
def is_on_surface(self, point):
# Just use any direction for a fake ray, we only need the distance
_, dist = ray_z_cylinder(self.length, self.radius, point, norm((1, 1, 1)))
if len(dist) == 0:
return False
dist = dist[0] # Only need closest intersection
if close_to_zero(dist):
# print("dist from point {} {} is_on_surface True".format(dist, point))
return True
# print("dist from point {} {} is_on_surface False".format(dist, point))
return False
def is_on_surface(self, point):
# Just use any direction for a fake ray, we only need the distance
_, dist = ray_z_cylinder(self.length, self.radius, point, norm((1,1,1)))
if len(dist) == 0:
return False
dist = dist[0] # Only need closest intersection
if close_to_zero(dist):
print("dist from point {} {} is_on_surface True".format(dist, point))
return True
print("dist from point {} {} is_on_surface False".format(dist, point))
return False
def next_hit(scene, ray):
""" Returns information about the next interface the ray makes with the scene.
Parameters
----------
scene : Scene
ray : Ray
Returns
-------
hit_node : Node
The node corresponding to the geometry object that was hit.
interface : tuple of Node
Two node: the `container` and the `adjacent` which correspond to the
materials either side of the interface.
point: tuple of float
The intersection point.
distance: float
Distance to the intersection point.
"""
# Intersections are in the local node's coordinate system
intersections = scene.intersections(ray.position, ray.direction)
# Remove on surface intersections
intersections = \
[x for x in intersections if not close_to_zero(x.distance)]
# Convert intersection points to world node
intersections = [x.to(scene.root) for x in intersections]
# Node which owns the surface
if len(intersections) == 0:
return None
# The surface being hit
hit = intersections[0]
if len(intersections) == 1:
hit_node = hit.hit
return hit_node, (hit_node, None), hit.point, hit.distance
container = find_container(intersections)
hit = intersections[0]
# Intersection point and distance from ray
point = hit.point
hit_node = hit.hit
distance = distance_between(ray.position, point)
if container == hit_node:
adjacent = intersections[1].hit
else:
adjacent = hit_node
return hit_node, (container, adjacent), point, distance
