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Aislo/B04_wf1_Surface/B04_wf1_Surface_Engine_Contour.py
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2026-07-05 21:27:23 +09:00

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Python

"""B04 등고선 추출 엔진.
5종 표현(regular_grid/triangular_mesh/bspline_surface/local_rbf_height_field/
meshfree_surfels)의 npz 모델에서 표고 격자를 환원하고, marching squares로
지정 간격 등고선 라인을 추출한다. DTM valid_mask를 footprint로 사용해
경계 누출을 차단한다.
"""
from pathlib import Path
from typing import Any
import numpy as np
from scipy.interpolate import RBFInterpolator, RectBivariateSpline
from skimage import measure
# 등고선 캐시 형식/추출 규칙이 바뀔 때 증가시킨다.
CONTOUR_EXTRACTOR_VERSION = 3
def extract_contours_from_grid(
x_coords: np.ndarray,
y_coords: np.ndarray,
z_grid: np.ndarray,
valid_mask: np.ndarray | None,
interval: float,
min_interval: float = 0.5,
scene_center: tuple[float, float, float] | None = None,
) -> list[dict[str, Any]]:
"""정규 표고 격자로부터 등고선 라인을 추출한다."""
interval = max(interval, min_interval)
finite_mask = np.isfinite(z_grid)
if valid_mask is not None:
finite_mask &= valid_mask
if not finite_mask.any():
return []
z_min = float(np.min(z_grid[finite_mask]))
z_max = float(np.max(z_grid[finite_mask]))
start_level = np.ceil(z_min / interval) * interval
levels = np.arange(start_level, z_max, interval)
if len(levels) == 0:
return []
if len(levels) > 500:
new_interval = (z_max - z_min) / 100.0
levels = np.arange(np.ceil(z_min / new_interval) * new_interval, z_max, new_interval)
interval = new_interval
contours_geojson_list: list[dict[str, Any]] = []
# marching squares의 NaN 문제 예방: 무효 영역을 sentinel(z_min-1000)로 채운다.
z_grid_masked = z_grid.copy()
if valid_mask is not None:
z_grid_masked[~valid_mask] = z_min - 1000.0
invalid_mask = ~np.isfinite(z_grid_masked)
if invalid_mask.any():
z_grid_masked[invalid_mask] = z_min - 1000.0
cx, cy, cz = scene_center if scene_center is not None else (0.0, 0.0, 0.0)
for level in levels:
for contour in measure.find_contours(z_grid_masked, level):
current_segment: list[list[float]] = []
for y_idx, x_idx in contour:
x_idx_c = np.clip(x_idx, 0, len(x_coords) - 1)
y_idx_c = np.clip(y_idx, 0, len(y_coords) - 1)
x_0, x_1 = int(np.floor(x_idx_c)), int(np.ceil(x_idx_c))
y_0, y_1 = int(np.floor(y_idx_c)), int(np.ceil(y_idx_c))
is_valid = True
if valid_mask is not None and not (
valid_mask[y_0, x_0]
and valid_mask[y_0, x_1]
and valid_mask[y_1, x_0]
and valid_mask[y_1, x_1]
):
is_valid = False
if not is_valid:
if len(current_segment) >= 2:
mid_idx = len(current_segment) // 2
contours_geojson_list.append(
{
"level": float(level),
"coordinates": current_segment,
"label_position": current_segment[mid_idx],
}
)
current_segment = []
continue
tx = x_idx_c - x_0
ty = y_idx_c - y_0
x_val = (1.0 - tx) * x_coords[x_0] + tx * x_coords[x_1]
y_val = (1.0 - ty) * y_coords[y_0] + ty * y_coords[y_1]
if scene_center is not None:
current_segment.append(
[
round(float(x_val - cx), 3),
round(float(level - cz), 3),
round(float(-(y_val - cy)), 3),
]
)
else:
current_segment.append(
[round(float(x_val), 3), round(float(y_val), 3), round(float(level), 3)]
)
if len(current_segment) >= 2:
mid_idx = len(current_segment) // 2
contours_geojson_list.append(
{
"level": float(level),
"coordinates": current_segment,
"label_position": current_segment[mid_idx],
}
)
return contours_geojson_list
def _load_footprint_mask(
model_npz_path: Path, x_coords: np.ndarray, y_coords: np.ndarray
) -> np.ndarray | None:
"""같은 source filter의 DTM valid_mask를 현재 격자에 최근접 리샘플한다."""
stem = Path(model_npz_path).stem
if stem.endswith("_smooth"):
stem = stem[:-7]
parts = stem.split("_", 1)
if len(parts) < 2:
return None
filter_key = parts[1]
dtm_path = Path(model_npz_path).parent / f"dtm_{filter_key}.npz"
if not dtm_path.exists():
return None
try:
d = np.load(dtm_path)
dtm_x = np.asarray(d["x"]).ravel()
dtm_y = np.asarray(d["y"]).ravel()
dtm_mask = np.asarray(d["valid_mask"], dtype=bool)
except Exception:
return None
if len(dtm_x) < 2 or len(dtm_y) < 2:
return None
def _nearest_idx(axis: np.ndarray, coords: np.ndarray) -> np.ndarray:
ascending = bool(axis[0] <= axis[-1])
a = axis if ascending else axis[::-1]
idx = np.clip(np.searchsorted(a, coords), 1, len(a) - 1)
idx = np.where(np.abs(a[idx - 1] - coords) <= np.abs(a[idx] - coords), idx - 1, idx)
return idx if ascending else (len(axis) - 1 - idx)
xi = _nearest_idx(dtm_x, np.asarray(x_coords, dtype=np.float64))
yi = _nearest_idx(dtm_y, np.asarray(y_coords, dtype=np.float64))
return dtm_mask[np.ix_(yi, xi)]
def _apply_footprint(
model_npz_path: Path, x_coords: np.ndarray, y_coords: np.ndarray, valid_mask: np.ndarray
) -> np.ndarray:
"""valid_mask에 DTM footprint를 교집합으로 적용한다 (형상 다르면 최근접 리샘플)."""
fp = _load_footprint_mask(model_npz_path, x_coords, y_coords)
if fp is not None:
if fp.shape == valid_mask.shape:
return valid_mask & fp
from scipy.ndimage import zoom
zoom_y = valid_mask.shape[0] / fp.shape[0]
zoom_x = valid_mask.shape[1] / fp.shape[1]
fp_resized = zoom(fp.astype(float), (zoom_y, zoom_x), order=0) > 0.5
if fp_resized.shape == valid_mask.shape:
return valid_mask & fp_resized
return valid_mask
def _tin_face_coverage_mask(
vertices: np.ndarray, faces: np.ndarray, xx: np.ndarray, yy: np.ndarray
) -> np.ndarray:
"""저장된 TIN 면이 실제로 덮는 XY 영역만 True로 반환한다."""
vertices = np.asarray(vertices)
faces = np.asarray(faces, dtype=np.int64)
if vertices.ndim != 2 or vertices.shape[1] < 2 or not len(faces):
return np.zeros(xx.shape, dtype=bool)
edges = np.vstack((faces[:, [0, 1]], faces[:, [1, 2]], faces[:, [2, 0]]))
edges = np.sort(edges, axis=1)
unique_edges, counts = np.unique(edges, axis=0, return_counts=True)
boundary_edges = unique_edges[counts == 1]
if not len(boundary_edges):
return np.zeros(xx.shape, dtype=bool)
from shapely import get_parts, intersects_xy, linestrings, polygonize, union_all
boundary_lines = linestrings(vertices[boundary_edges, :2])
polygons = list(get_parts(polygonize(boundary_lines)))
if not polygons:
return np.zeros(xx.shape, dtype=bool)
coverage = union_all(polygons)
xx_flat = np.asarray(xx, dtype=np.float64).ravel()
yy_flat = np.asarray(yy, dtype=np.float64).ravel()
res_flat = np.asarray(intersects_xy(coverage, xx_flat, yy_flat), dtype=bool)
return res_flat.reshape(xx.shape)
def _grid_axes(x_min: float, x_max: float, y_min: float, y_max: float, target_grid_m: float):
cols = max(2, int(np.ceil((x_max - x_min) / target_grid_m)) + 1)
rows = max(2, int(np.ceil((y_max - y_min) / target_grid_m)) + 1)
x_coords = np.linspace(x_min, x_max, cols, dtype=np.float32)
y_coords = np.linspace(y_min, y_max, rows, dtype=np.float32)
return x_coords, y_coords
def extract_contours(
model_npz_path: Path,
representation: str,
interval: float,
target_grid_m: float = 1.0,
scene_center: tuple[float, float, float] | None = None,
) -> list[dict[str, Any]]:
"""표현별 npz 모델에서 표고 격자를 환원한 뒤 등고선 리스트를 추출한다."""
model_npz_path = Path(model_npz_path)
if not model_npz_path.exists():
raise FileNotFoundError(f"모델 파일이 존재하지 않습니다: {model_npz_path}")
data = np.load(model_npz_path)
if representation == "regular_grid":
x_coords, y_coords, z_grid, valid_mask = (
data["x"],
data["y"],
data["z"],
data["valid_mask"],
)
current_res = (x_coords[-1] - x_coords[0]) / (len(x_coords) - 1)
step = max(1, int(round(target_grid_m / current_res)))
if step > 1:
return extract_contours_from_grid(
x_coords[::step],
y_coords[::step],
z_grid[::step, ::step],
valid_mask[::step, ::step],
interval,
scene_center=scene_center,
)
return extract_contours_from_grid(
x_coords, y_coords, z_grid, valid_mask, interval, scene_center=scene_center
)
if representation == "triangular_mesh":
from scipy.interpolate import griddata
vertices, faces = data["vertices"], data["faces"]
x_min, x_max = float(np.min(vertices[:, 0])), float(np.max(vertices[:, 0]))
y_min, y_max = float(np.min(vertices[:, 1])), float(np.max(vertices[:, 1]))
x_coords, y_coords = _grid_axes(x_min, x_max, y_min, y_max, target_grid_m)
xx, yy = np.meshgrid(x_coords, y_coords)
z_grid = griddata(vertices[:, :2], vertices[:, 2], (xx, yy), method="linear")
face_mask = _tin_face_coverage_mask(vertices, faces, xx, yy)
valid_mask = np.isfinite(z_grid) & face_mask
valid_mask = _apply_footprint(model_npz_path, x_coords, y_coords, valid_mask)
return extract_contours_from_grid(
x_coords, y_coords, z_grid, valid_mask, interval, scene_center=scene_center
)
if representation == "bspline_surface":
control_x, control_y, control_z = data["control_x"], data["control_y"], data["control_z"]
degree = int(data["degree"][0])
spline = RectBivariateSpline(
control_y,
control_x,
control_z,
kx=min(degree, len(control_y) - 1),
ky=min(degree, len(control_x) - 1),
s=float(len(control_x) * len(control_y)) * 0.01,
)
x_coords, y_coords = _grid_axes(
float(control_x[0]),
float(control_x[-1]),
float(control_y[0]),
float(control_y[-1]),
target_grid_m,
)
z_grid = np.asarray(spline(y_coords, x_coords), dtype=np.float32)
valid_mask = _apply_footprint(
model_npz_path, x_coords, y_coords, np.ones_like(z_grid, dtype=bool)
)
return extract_contours_from_grid(
x_coords, y_coords, z_grid, valid_mask, interval, scene_center=scene_center
)
if representation == "local_rbf_height_field":
centers_xy, center_z = data["centers_xy"], data["center_z"]
smoothing = float(data["smoothing"][0])
interpolator = RBFInterpolator(
centers_xy.astype(np.float64),
center_z.astype(np.float64),
neighbors=min(64, len(centers_xy)),
smoothing=smoothing,
kernel="thin_plate_spline",
)
x_min, x_max = float(np.min(centers_xy[:, 0])), float(np.max(centers_xy[:, 0]))
y_min, y_max = float(np.min(centers_xy[:, 1])), float(np.max(centers_xy[:, 1]))
x_coords, y_coords = _grid_axes(x_min, x_max, y_min, y_max, target_grid_m)
xx, yy = np.meshgrid(x_coords, y_coords)
z_values = interpolator(np.column_stack([xx.ravel(), yy.ravel()])).astype(np.float32)
z_grid = z_values.reshape(len(y_coords), len(x_coords))
valid_mask = _apply_footprint(
model_npz_path, x_coords, y_coords, np.ones_like(z_grid, dtype=bool)
)
return extract_contours_from_grid(
x_coords, y_coords, z_grid, valid_mask, interval, scene_center=scene_center
)
if representation == "meshfree_surfels":
from scipy.interpolate import griddata
from scipy.spatial import Delaunay
points = data["points"]
x_min, x_max = float(np.min(points[:, 0])), float(np.max(points[:, 0]))
y_min, y_max = float(np.min(points[:, 1])), float(np.max(points[:, 1]))
x_coords, y_coords = _grid_axes(x_min, x_max, y_min, y_max, target_grid_m)
xx, yy = np.meshgrid(x_coords, y_coords)
z_grid = griddata(points[:, :2], points[:, 2], (xx, yy), method="linear")
valid_mask = np.isfinite(z_grid)
try:
tri = Delaunay(points[:, :2])
hull_inside = tri.find_simplex(np.column_stack([xx.ravel(), yy.ravel()])) >= 0
valid_mask = valid_mask & hull_inside.reshape(xx.shape)
except Exception:
pass
valid_mask = _apply_footprint(model_npz_path, x_coords, y_coords, valid_mask)
return extract_contours_from_grid(
x_coords, y_coords, z_grid, valid_mask, interval, scene_center=scene_center
)
raise ValueError(f"지원하지 않는 표현 방식입니다: {representation}")