Java 3D Tiles Downloader

tiles-downloader-cli

A ridiculously fast, parallel Java CLI to download Google Photorealistic 3D Tiles GLB leaves within a spherical region.
No rotation, no baking, no transforms — just download.

Build

Requirements: Java 17+, Maven 3.8+

mvn -q -DskipTests clean package

This produces:

target/tiles-downloader-cli-1.0.0-all.jar

Usage

java -jar target/tiles-downloader-cli-1.0.0-all.jar \
  --key <API_KEY> \
  --lat <deg> --lng <deg> \
  --radius <meters> \
  -o <outdir> \
  [--parallel <n>] [--no-elevation] [-v] [-h]

Flags

• --key (required): Google API key.
• --lat, --lng (required): target center, in degrees.
• --radius (required): culling sphere radius, in meters (ECEF).
• -o, --out: output directory (default ./out).
• --parallel: max parallel network ops (default 10).
• --no-elevation: skip the Elevation API (assumes height=0 for ECEF).
• -v: verbose logs.

Examples

Download around San Francisco (with elevation, 16-way parallel):

java -jar target/tiles-downloader-cli-1.0.0-all.jar \
  --key YOUR_GOOGLE_API_KEY \
  --lat 37.7793 --lng -122.4193 --radius 250 \
  -o out --parallel 16 -v

Skip elevation (assume h=0), Los Angeles:

java -jar target/tiles-downloader-cli-1.0.0-all.jar \
  --key YOUR_GOOGLE_API_KEY \
  --lat 34.0522 --lng -118.2437 --radius 300 \
  -o out --parallel 12 --no-elevation

Output

• Files are saved as <SHA1>.glb into the output directory.

• The SHA1 is computed from the tile path + query, excluding key and session, so names are stable across runs.

• At the end, the tool prints:

  • Downloaded: N file(s).
  • DOWNLOADED_TILES: [...] — the list of filenames.

Performance & Exit Behavior

• Uses Java 17 HttpClient with HTTP/2 and connection reuse.
• Bounded parallelism for both parsing and downloading.

Notes

• Only .glb leaves are downloaded; sub-tilesets are followed recursively.
• Coarse culling uses a conservative sphere from each node’s boundingVolume.box.
• Be mindful of your Google Maps Platform quotas and Terms of Service.