code/superpoint_ops/batch_gen_superpoints_mp.py

"""Batch generate pycut superpoint.npy for all S3DIS rooms (multiprocessing)."""
import os
import sys
import time
import numpy as np
from scipy.spatial import cKDTree
from multiprocessing import Pool, cpu_count

SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
LIBCP_DIR = os.path.join(SCRIPT_DIR, "_cut_pursuit", "build", "src")
sys.path.insert(0, LIBCP_DIR)
sys.path.insert(0, SCRIPT_DIR)

import libcp
from lib_geo import (
    _normalize_xyz_np,
    _normalize_normals_np,
    _local_geom_features_chunked_np,
    _build_adj_graph_np,
    _edge_weights_chunked_np,
    _relabel_contiguous_np,
)

S3DIS_ROOT = "/mnt/data/AODUOLI/_work_biptv3/pointcept_framework/data/s3dis_official"
OUT_ROOT = os.path.join(SCRIPT_DIR, "outputs", "superpoint_pycut_all")


def merge_small_components(xyz, labels, min_size=50):
    counts = np.bincount(labels)
    small_mask = counts[labels] < min_size
    if not small_mask.any():
        return labels
    labels = labels.copy()
    large_mask = ~small_mask
    if not large_mask.any():
        return labels
    tree = cKDTree(xyz[large_mask])
    _, nn_idx = tree.query(xyz[small_mask], k=1)
    large_indices = np.where(large_mask)[0]
    labels[small_mask] = labels[large_indices[nn_idx]]
    return _relabel_contiguous_np(labels)


def generate_superpoints_pycut(
    xyz, normals=None,
    k_feat=10, k_adj=10, chunk_size=8192,
    normal_scale=0.25, lam=0.03, sigma=0.5,
    min_comp_weight=20, weight_decay=0.7,
    merge_min_size=50,
):
    xyz_norm = _normalize_xyz_np(xyz)
    geom_feat = _local_geom_features_chunked_np(xyz_norm, k_feat=k_feat, chunk_size=chunk_size)
    feat_parts = [geom_feat]
    if normals is not None:
        nn = _normalize_normals_np(normals)
        feat_parts.append(nn * normal_scale)
    Y = np.hstack(feat_parts).astype(np.float32)

    src, dst = _build_adj_graph_np(xyz_norm, k_adj=k_adj, mutual=False, undirected=True)
    ew = _edge_weights_chunked_np(Y.T, src, dst, lam=1.0, sigma=sigma)

    components, in_component = libcp.cutpursuit(
        Y,
        src.astype(np.uint32),
        dst.astype(np.uint32),
        ew.astype(np.float32),
        float(lam),
        int(min_comp_weight),
        0,
        float(weight_decay),
    )
    labels = _relabel_contiguous_np(np.asarray(in_component, dtype=np.int32))

    if merge_min_size > 0:
        labels = merge_small_components(xyz, labels, min_size=merge_min_size)

    return labels


def process_room(args):
    area, room = args
    room_dir = os.path.join(S3DIS_ROOT, area, room)
    coord_path = os.path.join(room_dir, "coord.npy")
    normal_path = os.path.join(room_dir, "normal.npy")

    if not os.path.exists(coord_path):
        return (area, room, -1, 0, 0.0, "no coord.npy")

    out_dir = os.path.join(OUT_ROOT, area, room)
    os.makedirs(out_dir, exist_ok=True)
    out_path = os.path.join(out_dir, "superpoint.npy")

    if os.path.exists(out_path):
        return (area, room, -1, 0, 0.0, "exists")

    coord = np.load(coord_path).astype(np.float32)
    normals = None
    if os.path.exists(normal_path):
        normals = np.load(normal_path).astype(np.float32)

    t0 = time.time()
    labels = generate_superpoints_pycut(
        coord, normals=normals,
        lam=0.03, sigma=0.5,
        k_feat=10, k_adj=10,
        merge_min_size=50,
    )
    dt = time.time() - t0
    n_sp = int(labels.max()) + 1

    np.save(out_path, labels)
    return (area, room, coord.shape[0], n_sp, dt, "done")


if __name__ == "__main__":
    os.makedirs(OUT_ROOT, exist_ok=True)

    tasks = []
    areas = sorted([d for d in os.listdir(S3DIS_ROOT) if d.startswith("Area_")])
    for area in areas:
        area_dir = os.path.join(S3DIS_ROOT, area)
        rooms = sorted([r for r in os.listdir(area_dir)
                       if os.path.isdir(os.path.join(area_dir, r))])
        for room in rooms:
            tasks.append((area, room))

    total = len(tasks)
    pending = []
    for area, room in tasks:
        out_path = os.path.join(OUT_ROOT, area, room, "superpoint.npy")
        if not os.path.exists(out_path):
            pending.append((area, room))

    print(f"Total: {total} rooms, already done: {total - len(pending)}, pending: {len(pending)}")

    n_workers = min(12, cpu_count())
    print(f"Using {n_workers} workers")

    t_global = time.time()
    done_count = 0

    with Pool(n_workers) as pool:
        for result in pool.imap_unordered(process_room, pending):
            done_count += 1
            area, room, n_pts, n_sp, dt, status = result
            if status == "done":
                print(f"[{done_count}/{len(pending)}] {area}/{room}: {n_pts} pts -> {n_sp} sp  ({dt:.1f}s)")
            elif status == "exists":
                print(f"[{done_count}/{len(pending)}] {area}/{room}: EXISTS")
            else:
                print(f"[{done_count}/{len(pending)}] {area}/{room}: SKIP ({status})")
            sys.stdout.flush()

    print(f"\nDone! Total time: {time.time() - t_global:.0f}s")