def setUp(self):
self.clean_state()
self.diameter = 0.1
self.aperture_origin = Position.from_xyz((10.0, 20.0, 30.0))
self.aperture_direction = Direction.from_xyz((1.0, 2.0, 3.0))
self.placement = Ray(self.aperture_origin, self.aperture_direction.normalized())
self.aperture = Aperture(placement=self.placement, diameter=self.diameter)
self.initial_wavefront = WaveFront.unit_sphere
self.orthogonal_directions = [
self.aperture_direction.cross(Direction.right).normalized(),
self.aperture_direction.cross(Direction.forward).normalized(),
self.aperture_direction.cross(Direction.backward).normalized(),
]
class TestAperture(unittest.TestCase):
"""
Test Aperture class
"""
def clean_state(self):
self.aperture = None
self.diameter = None
self.aperture_origin = None
self.aperture_direction = None
self.orthogonal_directions = None
self.placement = None
self.ray_location = None
self.orthogonal_direction = None
self.scale_factor = None
self.test_ray_distance = None
self.test_ray = None
self.initial_wavefront = None
self.filtered_wavefront = None
def setUp(self):
self.clean_state()
self.diameter = 0.1
self.aperture_origin = Position.from_xyz((10.0, 20.0, 30.0))
self.aperture_direction = Direction.from_xyz((1.0, 2.0, 3.0))
self.placement = Ray(self.aperture_origin, self.aperture_direction.normalized())
self.aperture = Aperture(placement=self.placement, diameter=self.diameter)
self.initial_wavefront = WaveFront.unit_sphere
self.orthogonal_directions = [
self.aperture_direction.cross(Direction.right).normalized(),
self.aperture_direction.cross(Direction.forward).normalized(),
self.aperture_direction.cross(Direction.backward).normalized(),
]
def tearDown(self):
self.clean_state()
def test_aperture_radius(self):
self.assertAlmostEqual(self.diameter / 2.0, self.aperture.radius)
def test_aperture_correctly_measures_ray_distances(self):
self.then_test_with_multiple_location_directions_and_scales()
def then_test_with_multiple_location_directions_and_scales(self):
for self.ray_location in [
Position.from_xyz((44.0, 33.0, 2.0)),
Position.from_xyz((-9.0, 3.0, -2.0)),
]:
self.then_test_location_with_multiple_direction_and_scales()
def then_test_location_with_multiple_direction_and_scales(self):
for self.orthogonal_direction in self.orthogonal_directions:
self.then_test_location_and_direction_with_multiple_scales()
def then_test_location_and_direction_with_multiple_scales(self):
for self.scale_factor in [1.0, 0.1, 0.01, 0.001, 1000.0]:
self.then_test_location_direction_and_scale()
def then_test_location_direction_and_scale(self):
self.when_test_ray_is_constructed()
self.when_test_ray_distance_is_measured()
self.then_test_ray_distance_is_correct()
def when_test_ray_is_constructed(self):
scaled_normal = self.orthogonal_direction.scale(self.scale_factor)
ray_endpoint = self.aperture_origin.add(scaled_normal)
ray_direction = ray_endpoint.difference(self.ray_location).normalized()
self.test_ray = Ray(self.ray_location, ray_direction)
def when_test_ray_distance_is_measured(self):
self.test_ray_distance = self.aperture.distance_to_ray(self.test_ray)
def then_test_ray_distance_is_correct(self):
self.assertAlmostEqual(self.scale_factor, self.test_ray_distance)
def test_volume_calculations(self):
# Testing the test to be sure expected volume is correct.
# The correct math using 1-cosine(angle) is inaccurate for small angles.
# Instead a more complex tangent based formula is used.
# This test makes sure the more complex formula is still correct.
self.assertEqual(0.0, self.volume_of_spherical_cone(0.0))
for angle in [0.1, 0.2, 0.5, 1.0, 0.01]:
cosine = math.cos(angle)
tangent = math.tan(angle)
expected_height_factor = 1.0 - cosine
actual_height_factor = self.height_factor_of_spherical_cone(tangent)
self.assertAlmostEqual(expected_height_factor, actual_height_factor)
def volume_of_spherical_cone(self, tangent):
height_factor = self.height_factor_of_spherical_cone(tangent)
volume = height_factor * math.pi * 2.0 / 3.0
return volume
def height_factor_of_spherical_cone(self, tangent):
tangent_squared = tangent * tangent
secant_squared = 1 + tangent_squared
secant = math.sqrt(secant_squared)
alpha_squared = tangent_squared + 2.0 * (1.0 - secant)
alpha = math.sqrt(alpha_squared)
height_factor = alpha / secant
return height_factor
@unittest.skip("slow test because it does a lot of calculation")
def test_aperture_filters_wavefront(self):
self.when_wavefront_is_filtered()
self.then_filter_wavefront_has_correct_properties()
def when_wavefront_is_filtered(self):
self.filtered_wavefront = self.aperture.filter_wavefront(self.initial_wavefront)
def then_filter_wavefront_has_correct_properties(self):
distance_to_aperture = vector_norm(self.aperture_origin.xyz)
tangent = self.aperture.radius / distance_to_aperture
expected_volume = self.volume_of_spherical_cone(tangent)
actual_volume = self.filtered_wavefront.volume
self.assertAlmostEqual(expected_volume, actual_volume, 3)
