def test_ray_differential(self):
r = Ray(Point(0, 0, 0), Vector(1, 2, 3))
rd = RayDifferential(Point(0, 0, 0), Vector(1, 2, 3))
# test copy constructor from Ray
rd.has_differentials = True
rd1 = RayDifferential.from_ray_differential(rd)
self.assertTrue(isinstance(rd1, RayDifferential))
self.assertEqual(rd1.o, rd.o)
self.assertEqual(rd1.d, rd.d)
self.assertEqual(rd1.rx_origin, rd.rx_origin)
self.assertEqual(rd1.ry_origin, rd.ry_origin)
self.assertEqual(rd1.rx_direction, rd.rx_direction)
self.assertEqual(rd1.ry_direction, rd.ry_direction)
self.assertEqual(rd1.has_differentials, rd.has_differentials)
# test copy constructor from Ray
rd2 = RayDifferential.from_ray(r)
self.assertTrue(isinstance(rd2, RayDifferential))
self.assertEqual(rd2.d, r.d)
self.assertEqual(rd2.has_differentials, False)
# test constructor from parent ray
rd3 = RayDifferential.from_ray_parent(r.o, r.d, r, r.mint)
self.assertTrue(isinstance(rd3, RayDifferential))
self.assertEqual(rd3.depth, r.depth + 1)
# test operator()
p = rd(1.7)
self.assertEqual(p, Point(1.7, 3.4, 5.1))
def test_transform_ray(self):
ray_differential = RayDifferential(origin=Point(1,2,3),
direction=Vector(10,20,30))
ray_differential.rx_origin = Point(4,5,6)
ray_differential.ry_origin = Point(5,6,7)
ray_differential.rx_direction = Vector(2,3,4)
ray_differential.ry_direction = Vector(3,4,5)
ray_transformed = translate(Point(10,20,30))(ray_differential)
self.assertTrue(isinstance(ray_transformed, RayDifferential))
self.assertEqual(ray_transformed.o, Point(11,22,33))
self.assertEqual(ray_transformed.d, Vector(10,20,30))
self.assertEqual(ray_transformed.rx_origin, Point(14,25,36))
self.assertEqual(ray_transformed.ry_origin, Point(15,26,37))
self.assertEqual(ray_transformed.rx_direction, Vector(2,3,4))
self.assertEqual(ray_transformed.ry_direction, Vector(3,4,5))
def generate_ray_differential(self, sample):
"""Generate a RayDifferential from the camera."""
# Generate raster and camera samples
p_ras = Point(sample.image_x, sample.image_y, 0)
p_camera = self.raster_to_camera(p_ras)
ray = RayDifferential(Point(0, 0, 0),
normalize(Vector.from_point(p_camera)), 0.0,
float('inf'))
# Modify ray for depth of field
if self.lens_radius > 0.0:
# Sample point on lens
lens_u, lens_v = concentric_sample_disk(sample.lens_u,
sample.lens_v)
lens_u *= self.lens_radius
lens_v *= self.lens_radius
# Compute point on plane of focus
ft = self.focal_distance / ray.d.z
p_focus = ray(ft)
# Update ray for effect of lens
ray.o = Point(lens_u, lens_v, 0.0)
ray.d = normalize(p_focus - ray.o)
ray.rx_origin = Point.from_point(ray.o)
ray.ry_origin = Point.from_point(ray.o)
ray.rx_direction = normalize(Vector.from_point(p_camera) + \
self.dx_camera)
ray.ry_direction = normalize(Vector.from_point(p_camera) + \
self.dy_camera)
ray.time = sample.time
ray = self.camera_to_world(ray)
ray.has_differentials = True
return 1.0, ray
