def sampling_points_from_frustum(height,
width,
focal,
principal_point,
depth_min=0.0,
depth_max=5.,
frustum_size=(256, 256, 256)):
"""Generates samples from a camera frustum."""
# ------------------ Get the rays from the camera ----------------------------
sampling_points = grid.generate((0., 0.),
(float(width) - 1, float(height) - 1),
(frustum_size[0], frustum_size[1]))
sampling_points = tf.reshape(sampling_points, [-1, 2]) # [h*w, 2]
rays = perspective.ray(sampling_points, focal, principal_point) # [h*w, 3]
# ------------------ Extract a volume in front of the camera -----------------
depth_tensor = grid.generate((depth_min, ), (depth_max, ),
(frustum_size[2], ))
sampling_volume = tf.multiply(tf.expand_dims(
rays, axis=-1), tf.transpose(depth_tensor)) # [h*w, 3, dstep]
sampling_volume = tf.transpose(sampling_volume,
[0, 2, 1]) # [h*w, dstep, 3]
sampling_volume = tf.reshape(sampling_volume, [-1, 3]) # [h*w*dstep, 3]
return sampling_volume
def test_ray_project_random(self):
"""Tests that the end point of the ray projects at the good location."""
tensor_size = np.random.randint(3)
tensor_shape = np.random.randint(1, 10, size=(tensor_size)).tolist()
random_point_2d = np.random.normal(size=tensor_shape + [2])
random_focal = np.random.normal(size=tensor_shape + [2])
random_principal_point = np.random.normal(size=tensor_shape + [2])
ray_3d = perspective.ray(random_point_2d, random_focal,
random_principal_point)
point_2d = perspective.project(ray_3d, random_focal, random_principal_point)
self.assertAllClose(random_point_2d, point_2d, rtol=1e-3)
def test_project_ray_random(self):
"""Tests that that ray is pointing toward the correct location."""
tensor_size = np.random.randint(3)
tensor_shape = np.random.randint(1, 10, size=(tensor_size)).tolist()
random_point_3d = np.random.normal(size=tensor_shape + [3])
random_focal = np.random.normal(size=tensor_shape + [2])
random_principal_point = np.random.normal(size=tensor_shape + [2])
random_depth = np.expand_dims(random_point_3d[..., 2], axis=-1)
point_2d = perspective.project(random_point_3d, random_focal,
random_principal_point)
ray_3d = perspective.ray(point_2d, random_focal, random_principal_point)
ray_3d = random_depth * ray_3d
self.assertAllClose(random_point_3d, ray_3d, rtol=1e-3)