From b16ceac9c9b352e69e4c8f10879db046db6a9912 Mon Sep 17 00:00:00 2001
From: Sean Collins <173011278+SMC17@users.noreply.github.com>
Date: Tue, 19 May 2026 16:35:58 -0400
Subject: [PATCH] docs(h3-hexagon-layer): add GeoJSON FeatureCollection example

When ingesting a GeoJSON FeatureCollection where each feature's
properties carries the H3 cell ID (a common export pattern from
geopandas, QGIS, h3-py, and custom spatial-index pipelines), the
default getHexagon accessor (object => object.hexagon) silently
returns undefined because GeoJSON parsers surface features as
{type, geometry, properties} objects.

This adds a worked example to the H3HexagonLayer docs showing the
getHexagon: d => d.properties.h3_id override so the recipe is
discoverable without reading the source.

Tested against a 1,665-feature H3 res-5 FeatureCollection export.

Docs-only; no code touched.
---
 .../geo-layers/h3-hexagon-layer.md            | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/docs/api-reference/geo-layers/h3-hexagon-layer.md b/docs/api-reference/geo-layers/h3-hexagon-layer.md
index b3e9260718a..547f02f02ea 100644
--- a/docs/api-reference/geo-layers/h3-hexagon-layer.md
+++ b/docs/api-reference/geo-layers/h3-hexagon-layer.md
@@ -123,6 +123,38 @@ function App() {
 </Tabs>
 
 
+### Consuming H3 cells from a GeoJSON FeatureCollection
+
+A common export pattern is GeoJSON where each feature's `properties`
+carries the H3 cell ID as a string (produced by `geopandas`, QGIS,
+`h3-py`, or a custom spatial-index pipeline). The default
+`getHexagon: object => object.hexagon` accessor returns `undefined`
+for these features because GeoJSON parsers surface them as
+`{type, geometry, properties}` objects.
+
+Override `getHexagon` to pull the cell ID out of `properties`:
+
+```js
+import {H3HexagonLayer} from '@deck.gl/geo-layers';
+
+new H3HexagonLayer({
+  id: 'h3-cells-from-geojson',
+  data: 'cells.geojson',  // FeatureCollection; each feature.properties carries h3_id
+  pickable: true,
+  filled: true,
+  extruded: true,
+  getHexagon: d => d.properties.h3_id,
+  getFillColor: d => [255, (1 - d.properties.value) * 255, 0],
+  getElevation: d => d.properties.value * 1000
+});
+```
+
+Any per-feature value to be styled or extruded by lives under
+`d.properties.*` in this shape. The geometry on each feature is
+ignored — `H3HexagonLayer` reconstructs the hexagon from the cell
+ID via `cellToBoundary`.
+
+
 ## Installation
 
 To install the dependencies from NPM: