Files
calibration/code/visualize_pair_3d.py
T

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6.5 KiB
Python

#!/usr/bin/env python3
"""Interactive 3D comparison of raw, RTK, GICP and hand-eye-predicted motion."""
import argparse
import json
import numpy as np
from scipy.spatial.transform import Rotation
from rigorous_calibration import (
inverse_transform, load_stations, rotation_angle_deg, rpy_deg, transform_points,
)
COLORS = {
"target": [0.10, 0.65, 1.00],
"source": [1.00, 0.35, 0.05],
}
def cloud(o3d, points, color, voxel):
item = o3d.geometry.PointCloud()
item.points = o3d.utility.Vector3dVector(points)
item = item.voxel_down_sample(voxel)
item.paint_uniform_color(color)
return item
def delta_components(reference, candidate):
"""Components of reference^-1*candidate, plus coordinate-invariant norms."""
delta = inverse_transform(reference) @ candidate
translation = np.asarray(delta[:3, 3], float)
return {
"translation_xyz_cm": (translation * 100.0).tolist(),
"translation_norm_cm": float(np.linalg.norm(translation) * 100.0),
"rotation_rpy_deg_xyz": rpy_deg(delta[:3, :3]),
"rotation_angle_deg": rotation_angle_deg(delta[:3, :3]),
}
def body_left_rpy(x, rpy_correction_deg):
correction = np.eye(4)
correction[:3, :3] = Rotation.from_euler(
"xyz", np.asarray(rpy_correction_deg, float), degrees=True
).as_matrix()
return correction @ x
def print_delta(name, reference, candidate):
item = delta_components(reference, candidate)
tx, ty, tz = item["translation_xyz_cm"]
roll, pitch, yaw = item["rotation_rpy_deg_xyz"]
print(
f"{name}: B^-1*motion translation xyz = "
f"[{tx:+.4f}, {ty:+.4f}, {tz:+.4f}] cm; "
f"rpy xyz = [{roll:+.4f}, {pitch:+.4f}, {yaw:+.4f}] deg; "
f"norm = {item['translation_norm_cm']:.4f} cm / "
f"{item['rotation_angle_deg']:.6f} deg"
)
return item
def main():
import open3d as o3d
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument("--frames", required=True)
parser.add_argument("--pairs", required=True)
parser.add_argument("--extrinsic", required=True)
parser.add_argument("--pair-index", type=int, default=0)
parser.add_argument("--voxel", type=float, default=0.10)
parser.add_argument(
"--left-rpy-deg", nargs=3, type=float, default=[0.0, 0.0, 0.0],
metavar=("ROLL", "PITCH", "YAW"),
help="optional body-frame left correction applied as DeltaR_body * X",
)
args = parser.parse_args()
stations = load_stations(args.frames, 1.0, 60.0)
with np.load(args.pairs, allow_pickle=False) as data:
if len(stations) != len(data["station_times"]):
raise ValueError(
f"frames contain {len(stations)} stations but pair file records "
f"{len(data['station_times'])}"
)
if not 0 <= args.pair_index < len(data["A"]):
raise IndexError(
f"pair-index {args.pair_index} outside [0,{len(data['A']) - 1}]"
)
a_ij = np.asarray(data["A"][args.pair_index], float)
b_gicp = np.asarray(data["B"][args.pair_index], float)
i, j = np.asarray(data["meta"][args.pair_index, :2], int)
with open(args.extrinsic, encoding="utf-8-sig") as stream:
result = json.load(stream)
x = np.asarray(result["matrix_4x4"], float)
b_calibrated = inverse_transform(x) @ a_ij @ x
transforms = {
"1 raw": np.eye(4),
"2 RTK initial (X0=I)": a_ij,
"3 GICP B": b_gicp,
"4 calibrated X^-1 A X": b_calibrated,
}
correction = np.asarray(args.left_rpy_deg, float)
if np.any(np.abs(correction) > 0.0):
x_test = body_left_rpy(x, correction)
transforms[
f"5 test body-left RPY {correction.tolist()} deg"
] = inverse_transform(x_test) @ a_ij @ x_test
target = stations[i][3]
source = stations[j][3]
print(f"pair_index={args.pair_index}, station {i} <- {j}")
print("blue = target station i; orange = source station j after selected transform")
print("keys: 1 raw | 2 RTK initial | 3 GICP | 4 calibrated | 5 test correction | Q/Esc exit")
print(
"IMPORTANT: delta xyz/rpy are components of B^-1*(X^-1*A*X), expressed "
"in station-j LiDAR coordinates; screen-left/right depends on the 3D camera view."
)
baseline = print_delta("mode 4 minus mode 3", b_gicp, b_calibrated)
roll, pitch, yaw = np.abs(baseline["rotation_rpy_deg_xyz"])
if max(roll, pitch) > max(0.10, 2.0 * yaw):
print("diagnosis: roll/pitch components dominate yaw; do not prioritize yaw tuning for this pair.")
tx, ty, tz = np.abs(baseline["translation_xyz_cm"])
if tz > max(tx, ty):
print("diagnosis: the largest translation component is relative Z, not lateral XY.")
body_up = np.array([0.0, 0.0, 1.0])
if np.linalg.norm(a_ij[:3, :3] @ body_up - body_up) < 1e-8:
print(
"observability: this A preserves the body Z axis, so body-left X.z "
"translation is unobservable from this pair; use ground/external height constraints."
)
if "5 test body-left RPY " + str(correction.tolist()) + " deg" in transforms:
print_delta("mode 5 minus mode 3", b_gicp, list(transforms.values())[-1])
viewer = o3d.visualization.VisualizerWithKeyCallback()
viewer.create_window("Rigorous LiDAR registration inspection - 3D", 1400, 900)
target_cloud = cloud(o3d, target, COLORS["target"], args.voxel)
source_cloud = cloud(o3d, source, COLORS["source"], args.voxel)
viewer.add_geometry(target_cloud)
viewer.add_geometry(source_cloud)
axes = o3d.geometry.TriangleMesh.create_coordinate_frame(size=1.0)
viewer.add_geometry(axes)
current = np.eye(4)
def select(name):
def callback(vis):
nonlocal current
desired = transforms[name]
source_cloud.transform(desired @ inverse_transform(current))
current = desired
vis.update_geometry(source_cloud)
if name == "3 GICP B":
print(f"{name}: reference registration B; delta = 0")
else:
print_delta(name + " minus mode 3", b_gicp, desired)
return False
return callback
for key, name in zip((ord("1"), ord("2"), ord("3"), ord("4"), ord("5")), transforms):
viewer.register_key_callback(key, select(name))
viewer.get_render_option().background_color = np.array([0.02, 0.02, 0.02])
viewer.get_render_option().point_size = 2.0
viewer.run()
viewer.destroy_window()
if __name__ == "__main__":
main()