@developmentseed/deck.gl-zarr

High-level deck.gl layer for rendering GeoZarr datasets directly from a Zarr store, with on-the-fly reprojection to Web Mercator.

This package builds on @developmentseed/deck.gl-raster and @developmentseed/geozarr to render Zarr arrays as a tiled raster source. It uses zarrita for store access, pairs the Zarr's native chunk grid with deck.gl's TileLayer, and reprojects each chunk into the Web Mercator viewport.

Quick Start

import { ZarrLayer } from "@developmentseed/deck.gl-zarr";
import * as zarr from "zarrita";

// The user creates the zarrita store; wrap it with middleware as needed
const store = new zarr.FetchStore("https://example.com/my-dataset.zarr");
const node = await zarr.open(store, { kind: "group" });

const layer = new ZarrLayer({
  id: "zarr-layer",
  node,
  // One entry per non-spatial dim. Use `null` for the default slice,
  // a number to pin to an index, or a `zarr.Slice` for a range.
  selection: { band: null },
  getTileData,
  renderTile,
});

The caller supplies two callbacks:

• getTileData(arr, options) — receives the opened zarr array for the requested level and a pre-built sliceSpec. Call zarr.get(arr, options.sliceSpec) and convert the result into whatever shape your renderTile expects.
• renderTile(data) — convert that result into a RenderTileResult (an ImageData/texture, or a custom luma.gl RenderPipeline).

This split keeps {@link ZarrLayer} agnostic about data type and rendering pipeline — the layer handles tiling, level selection, and reprojection; you decide how chunks become pixels.

Features

• GeoZarr-aware: Reads the spatial, multiscales, and geo-proj conventions to derive the level pyramid, per-level affine transforms, and CRS.
• Single- and multi-resolution support: A plain [H, W] or [bands, H, W] Zarr array works as a single-level source; a multiscale group is rendered as a pyramid.
• On-the-fly reprojection: Source CRS → Web Mercator using @developmentseed/raster-reproject, with no server-side tile service.
• Caller-owned store: Pass a pre-opened zarr.Array or zarr.Group so you control consolidation, range coalescing, authentication, and version selection.