#!/usr/bin/env python3 # -*- coding: utf-8 -*- """ UE4-Stereo -- stop-and-rotate acquisition (Scenes 1 and 2). Flies a closed-loop route in Unreal Engine 4.27 / Microsoft AirSim, recording synchronized stereo RGB images, planar metric depth and 6-DoF poses. The vehicle is commanded through successive position and heading targets: it flies to a waypoint, stops, rotates in place, and only then proceeds. For the continuous-motion variant used in Scenes 3 and 4 see `acquire_continuous.py`. See README.md for the output format, the camera model and the reference-frame conventions. Example: python acquire_stepwise.py --output scene_1/sequence01 \ --route route_a_dir1 --baseline 0.24 Requires airsim, numpy and opencv-python, with the simulator already running. """ from __future__ import annotations import argparse import math import os import threading import time import airsim import cv2 import numpy as np # --------------------------------------------------------------------------- # Routes. Waypoints are (x, y, z, yaw) in the AirSim world frame: metres, z # negative upwards, yaw in degrees. "_offset" marks the laterally displaced # variants; in route_b these are also 0.5 m higher. "_dir2" runs the loop # backwards. # --------------------------------------------------------------------------- ROUTES: dict[str, list[tuple[float, float, float, float]]] = { "route_a_dir1": [ (0, 0, -2.5, 0), (17, 0, -2.5, 90), (17, 12, -2.5, 0), (28, 12, -2.5, -90), (28, -14, -2.5, 180), (0, -14, -2.5, 90), (0, 0, -2.5, 0) ], "route_a_dir1_offset": [ (0, 0, -2.5, 0), (18, 0, -2.5, 90), (18, 11, -2.5, 0), (29, 11, -2.5, -90), (29, -15, -2.5, 180), (0, -15, -2.5, 90), (0, 0, -2.5, 0) ], "route_a_dir2": [ (0, 0, -2.5, -90), (0, -14, -2.5, 0), (28, -14, -2.5, 90), (28, 12, -2.5, 180), (17, 12, -2.5, -90), (17, 0, -2.5, 180), (0, 0, -2.5, 0) ], "route_a_dir2_offset": [ (0, 0, -2.5, -90), (0, -15, -2.5, 0), (29, -15, -2.5, 90), (29, 11, -2.5, 180), (18, 11, -2.5, -90), (18, 0, -2.5, 180), (0, 0, -2.5, 0) ], "route_b_dir1": [ (0, 0, -2.5, 0), (10.5, 0, -2.5, 90), (10.5, 21.3, -2.5, 0), (16, 21.3, -2.5, -90), (16, 11, -2.5, 0), (27, 11, -2.5, -90), (27, -1, -2.5, 180), (20, -1, -2.5, -90), (20, -15.5, -2.5, 180), (0, -15.5, -2.5, 90), (0, 0, -2.5, 0) ], "route_b_dir1_offset": [ (0, 0, -3, 0), (11, 0, -3, 90), (11, 21.3, -3, 0), (15, 21.3, -3, -90), (15, 10, -3, 0), (28, 10, -3, -90), (28, 0, -3, 180), (19, 0, -3, -90), (19, -15.5, -3, 180), (1, -15.5, -3, 90), (0, 0, -3, 0) ], "route_b_dir2": [ (0, 0, -2.5, -90), (0, -15.5, -2.5, 0), (20, -15.5, -2.5, 90), (20, -1, -2.5, 0), (27, -1, -2.5, 90), (27, 11, -2.5, 180), (16, 11, -2.5, 90), (16, 21.3, -2.5, 180), (10.5, 21.3, -2.5, -90), (10.5, 0, -2.5, 180), (0, 0, -2.5, 0) ], "route_b_dir2_offset": [ (0, 0, -3, -90), (1, -15.5, -3, 0), (19, -15.5, -3, 90), (19, 0, -3, 0), (28, 0, -3, 90), (28, 10, -3, 180), (15, 10, -3, 90), (15, 21.3, -3, 180), (11, 21.3, -3, -90), (11, 1, -3, 180), (0, 0, -3, 0) ], } # -------------------------------------------------------------------------- # Rig extrinsics (relative to the vehicle body frame, NED: +z is down) # -------------------------------------------------------------------------- CAMERA_FORWARD_M = 1.00 # x offset of both cameras CAMERA_DOWN_M = 0.10 # z offset of both cameras CAMERA_PITCH_DEG = -23.0 # both cameras tilt downwards by this angle SUBFOLDERS = ("left_rgb", "right_rgb", "depth_npy", "depth_visual") MOVE_SPEED_MPS = 1.0 # speed passed to moveToPositionAsync ROTATE_SPEED_DPS = 2.0 # rotation rate passed to rotateToYawAsync def decode_rgb(response) -> np.ndarray | None: if response.width <= 0 or response.height <= 0: return None return np.frombuffer(response.image_data_uint8, dtype=np.uint8).reshape( response.height, response.width, 3) def decode_depth(response) -> np.ndarray | None: if response.width <= 0 or response.height <= 0: return None depth = np.array(response.image_data_float, dtype=np.float32).reshape( response.height, response.width) return np.nan_to_num(depth, nan=0.0, posinf=0.0, neginf=0.0) def capture_loop(stop_event: threading.Event, output_dir: str, period_s: float, depth_visual: bool) -> None: client = airsim.MultirotorClient() client.confirmConnection() requests = [ airsim.ImageRequest("front-left", airsim.ImageType.Scene, pixels_as_float=False, compress=False), airsim.ImageRequest("front-right", airsim.ImageType.Scene, pixels_as_float=False, compress=False), airsim.ImageRequest("front-left", airsim.ImageType.DepthPlanar, pixels_as_float=True, compress=False), ] gt_path = os.path.join(output_dir, "groundtruth.txt") rgb_path = os.path.join(output_dir, "associate_rgb.txt") rgbd_path = os.path.join(output_dir, "associate_rgbd.txt") with open(gt_path, "w", encoding="utf-8") as gt_file, \ open(rgb_path, "w", encoding="utf-8") as assoc_rgb, \ open(rgbd_path, "w", encoding="utf-8") as assoc_rgbd: gt_file.write("# timestamp tx ty tz qx qy qz qw\n") assoc_rgb.write("# timestamp_left left_image timestamp_right right_image\n") assoc_rgbd.write("# timestamp_left left_image timestamp_depth depth_image\n") seq_counter = 0 while not stop_event.is_set(): ts_str = f"{time.time():.9f}" pose = client.simGetVehiclePose() p, q = pose.position, pose.orientation gt_file.write( f"{ts_str} {p.x_val:.6f} {p.y_val:.6f} {p.z_val:.6f} " f"{q.x_val:.6f} {q.y_val:.6f} {q.z_val:.6f} {q.w_val:.6f}\n") responses = client.simGetImages(requests) seq_name = f"{seq_counter:06d}" rel_left = f"left_rgb/{seq_name}.png" rel_right = f"right_rgb/{seq_name}.png" rel_depth = f"depth_npy/{seq_name}.npy" left = decode_rgb(responses[0]) if left is not None: cv2.imwrite(os.path.join(output_dir, rel_left), left) right = decode_rgb(responses[1]) if right is not None: cv2.imwrite(os.path.join(output_dir, rel_right), right) depth = decode_depth(responses[2]) if depth is not None: np.save(os.path.join(output_dir, rel_depth), depth) if depth_visual: preview = cv2.normalize(depth, None, 0, 255, cv2.NORM_MINMAX, dtype=cv2.CV_8U) cv2.imwrite(os.path.join(output_dir, "depth_visual", f"{seq_name}.png"), preview) assoc_rgb.write(f"{ts_str} {rel_left} {ts_str} {rel_right}\n") assoc_rgbd.write(f"{ts_str} {rel_left} {ts_str} {rel_depth}\n") seq_counter += 1 time.sleep(period_s) def configure_cameras(client: airsim.MultirotorClient, baseline: float, convergence_deg: float) -> None: half = baseline / 2.0 pitch = math.radians(CAMERA_PITCH_DEG) toe = math.radians(convergence_deg) client.simSetCameraPose("front-left", airsim.Pose( airsim.Vector3r(CAMERA_FORWARD_M, -half, CAMERA_DOWN_M), airsim.to_quaternion(pitch, 0.0, toe))) client.simSetCameraPose("front-right", airsim.Pose( airsim.Vector3r(CAMERA_FORWARD_M, half, CAMERA_DOWN_M), airsim.to_quaternion(pitch, 0.0, -toe))) def parse_args() -> argparse.Namespace: ap = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter) ap.add_argument("--output", required=True, help="directory for this sequence; created if absent") ap.add_argument("--route", required=True, choices=sorted(ROUTES), help="route to fly") ap.add_argument("--baseline", type=float, default=0.24, help="stereo baseline in metres (default: 0.24)") ap.add_argument("--convergence", type=float, default=0.0, help="inward toe-in per camera in degrees (default: 0, parallel)") ap.add_argument("--period", type=float, default=0.1, help="sleep between capture iterations in seconds " "(default: 0.1; the achieved rate is lower)") ap.add_argument("--depth-visual", action="store_true", help="also write 8-bit depth previews (not metric)") return ap.parse_args() def main() -> None: args = parse_args() for sub in SUBFOLDERS: if sub == "depth_visual" and not args.depth_visual: continue os.makedirs(os.path.join(args.output, sub), exist_ok=True) waypoints = ROUTES[args.route] client = airsim.MultirotorClient() client.confirmConnection() client.enableApiControl(True) client.armDisarm(True) client.takeoffAsync().join() configure_cameras(client, args.baseline, args.convergence) stop_event = threading.Event() capture_thread = threading.Thread( target=capture_loop, args=(stop_event, args.output, args.period, args.depth_visual), daemon=True) capture_thread.start() print(f"Flying '{args.route}' ({len(waypoints)} waypoints)") try: for x, y, z, yaw in waypoints: client.moveToPositionAsync(x, y, z, MOVE_SPEED_MPS).join() client.rotateToYawAsync(yaw, ROTATE_SPEED_DPS).join() finally: stop_event.set() capture_thread.join() print("Capture finished. Returning home.") client.goHomeAsync().join() client.armDisarm(False) client.enableApiControl(False) if __name__ == "__main__": main()