From dc0729fc5fd408f989489c329dbb10156af67de4 Mon Sep 17 00:00:00 2001
From: htlee <htlee@gcsc.co.kr>
Date: Sun, 15 Feb 2026 13:15:41 +0900
Subject: [PATCH] fix(map): reduce bathymetry fill complexity at low zoom

---
 apps/web/src/widgets/map3d/Map3D.tsx | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/apps/web/src/widgets/map3d/Map3D.tsx b/apps/web/src/widgets/map3d/Map3D.tsx
index fb7685a..e4cebbf 100644
--- a/apps/web/src/widgets/map3d/Map3D.tsx
+++ b/apps/web/src/widgets/map3d/Map3D.tsx
@@ -218,6 +218,10 @@ function injectOceanBathymetryLayers(style: StyleSpecification, maptilerKey: str
     type: "fill",
     source: oceanSourceId,
     "source-layer": "contour",
+    // Very low zoom tiles can contain extremely complex polygons (coastline/detail),
+    // which may exceed MapLibre's per-segment 16-bit vertex limit and render incorrectly.
+    // We keep the fill starting at a more reasonable zoom.
+    minzoom: 4,
     paint: {
       // Dark-mode friendly palette (shallow = slightly brighter; deep = near-black).
       "fill-color": bathyFillColor,