From 83168119b815865302ceb720937fdcd9f063b86e Mon Sep 17 00:00:00 2001
From: "s0wlz (Matthias Puchstein)" <matthias@puchstein.lu>
Date: Sat, 13 Dec 2025 18:07:57 +0100
Subject: [PATCH] Improve heightmap export stability

---
 export_heightmaps.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/export_heightmaps.py b/export_heightmaps.py
index 0a5395b..9eba2c3 100644
--- a/export_heightmaps.py
+++ b/export_heightmaps.py
@@ -23,8 +23,8 @@ if ds is None:
 
 band = ds.GetRasterBand(1)
 
-# Strategy B: compute global min/max for CURRENT downloaded AOI
-gmin, gmax = band.ComputeRasterMinMax(True)
+# Strategy B: compute global min/max for CURRENT downloaded AOI (full scan for stability)
+gmin, gmax = band.ComputeRasterMinMax(False)
 print(f"GLOBAL_MIN={gmin}, GLOBAL_MAX={gmax}")
 
 # Export manifest for Unity placement later
@@ -59,7 +59,8 @@ with open(manifest_path, "w", encoding="utf-8") as f:
             width=OUT_RES,
             height=OUT_RES,
             resampleAlg=RESAMPLE,
-            dstNodata=-9999,
+            srcNodata=-9999,
+            dstNodata=gmin,  # fill nodata with global min to avoid deep pits
         )
         gdal.Warp(tmp_path, ds, options=warp_opts)