wrote a script to automate the export to unity

export_heightmaps.py

@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+import glob
+import math
+import os
+
+from osgeo import gdal
+
+RAW_DIR = "raw_dgm1"
+VRT_PATH = "work/dgm.vrt"
+OUT_DIR = "export_unity/height_png16"
+
+TILE_SIZE_M = 1000  # real-world tile size in meters
+OUT_RES = 1025  # Unity Terrain-friendly resolution (2^n + 1)
+RESAMPLE = "bilinear"
+
+os.makedirs("work", exist_ok=True)
+os.makedirs(OUT_DIR, exist_ok=True)
+
+# Open VRT
+ds = gdal.Open(VRT_PATH)
+if ds is None:
+    raise SystemExit(f"Could not open {VRT_PATH}. Did you run gdalbuildvrt?")
+
+band = ds.GetRasterBand(1)
+
+# Strategy B: compute global min/max for CURRENT downloaded AOI
+gmin, gmax = band.ComputeRasterMinMax(True)
+print(f"GLOBAL_MIN={gmin}, GLOBAL_MAX={gmax}")
+
+# Export manifest for Unity placement later
+manifest_path = os.path.join("export_unity", "tile_index.csv")
+with open(manifest_path, "w", encoding="utf-8") as f:
+    f.write("tile_id,xmin,ymin,xmax,ymax,global_min,global_max,out_res\n")
+
+    for tif in sorted(glob.glob(os.path.join(RAW_DIR, "*.tif"))):
+        tds = gdal.Open(tif)
+        if tds is None:
+            print(f"Skipping unreadable: {tif}")
+            continue
+
+        gt = tds.GetGeoTransform()
+        ulx, xres, _, uly, _, yres = gt  # yres typically negative in north-up rasters
+
+        # Snap tile bounds to the 1000 m grid to avoid drift/seams.
+        # (This also neutralizes the 1001×1001 overlap nuance.)
+        xmin = math.floor(ulx / TILE_SIZE_M) * TILE_SIZE_M
+        ymax = math.ceil(uly / TILE_SIZE_M) * TILE_SIZE_M
+        xmax = xmin + TILE_SIZE_M
+        ymin = ymax - TILE_SIZE_M
+
+        base = os.path.splitext(os.path.basename(tif))[0]
+        tile_id = base  # keep stable naming = easy re-export + reimport
+
+        tmp_path = os.path.join("work", f"{tile_id}_tmp.tif")
+        out_path = os.path.join(OUT_DIR, f"{tile_id}.png")
+
+        warp_opts = gdal.WarpOptions(
+            outputBounds=(xmin, ymin, xmax, ymax),
+            width=OUT_RES,
+            height=OUT_RES,
+            resampleAlg=RESAMPLE,
+            dstNodata=-9999,
+        )
+        gdal.Warp(tmp_path, ds, options=warp_opts)
+
+        # Scale to UInt16 (0..65535) using Strategy-B global min/max
+        trans_opts = gdal.TranslateOptions(
+            outputType=gdal.GDT_UInt16,
+            scaleParams=[(gmin, gmax, 0, 65535)],
+            format="PNG",
+        )
+        gdal.Translate(out_path, tmp_path, options=trans_opts)
+
+        f.write(f"{tile_id},{xmin},{ymin},{xmax},{ymax},{gmin},{gmax},{OUT_RES}\n")
+        print(f"Wrote {out_path}")
+
+print(f"Manifest: {manifest_path}")

export_unity/tile_index.csv

@@ -0,0 +1,11 @@
+tile_id,xmin,ymin,xmax,ymax,global_min,global_max,out_res
+dgm1_32_328_5511,327000,5512000,328000,5513000,124.13099670410156,297.1679992675781,1025
+dgm1_32_328_5512,327000,5513000,328000,5514000,124.13099670410156,297.1679992675781,1025
+dgm1_32_328_5513,327000,5514000,328000,5515000,124.13099670410156,297.1679992675781,1025
+dgm1_32_328_5514,327000,5515000,328000,5516000,124.13099670410156,297.1679992675781,1025
+dgm1_32_328_5515,327000,5516000,328000,5517000,124.13099670410156,297.1679992675781,1025
+dgm1_32_329_5511,328000,5512000,329000,5513000,124.13099670410156,297.1679992675781,1025
+dgm1_32_329_5512,328000,5513000,329000,5514000,124.13099670410156,297.1679992675781,1025
+dgm1_32_329_5513,328000,5514000,329000,5515000,124.13099670410156,297.1679992675781,1025
+dgm1_32_329_5514,328000,5515000,329000,5516000,124.13099670410156,297.1679992675781,1025
+dgm1_32_329_5515,328000,5516000,329000,5517000,124.13099670410156,297.1679992675781,1025