OGC 3D Tiles

DroneDB supports OGC 3D Tiles for efficient streaming of large 3D models in the browser. 3D Tiles can be generated from existing OBJ/glTF/GLB models, or ingested directly as .3tz archives (ZIP-packaged 3D Tiles with tileset.json at the root).

Supported formats

Format	Extension	Description
OBJ	.obj	Wavefront 3D model (requires MTL + textures)
glTF	.gltf / .glb	GL Transmission Format
3D Tiles archive	.3tz	ZIP archive containing a tileset.json and associated tile files

Entry types

• A .3tz archive is indexed as a Tiles3D entry.
• An OBJ/glTF/GLB file is indexed as a Model entry.

When a Model entry is built, DroneDB generates a Nexus (NXS/NXZ) stream as the primary artifact and co-produces an additive OGC 3D Tiles tileset in a sibling 3dtiles/ folder as a best-effort artifact for the unified 3D viewer.

Generating 3D Tiles from the CLI

Use the ddb 3dtiles command (requires the optional Obj2Tiles binary):

# Generate a 3D Tiles tileset next to the input
ddb 3dtiles model.obj

# Specify an output directory
ddb 3dtiles model.obj ./3dtiles

# Force a local (non-georeferenced) tileset
ddb 3dtiles model.obj ./3dtiles --local

# Explicitly set a WGS84 origin
ddb 3dtiles model.obj ./3dtiles --lat 43.7 --lon 10.4 --alt 50

Georeferencing

By default, ddb 3dtiles auto-detects georeferencing from sidecar files next to the input model (following the ODM/Obj2Tiles convention). You can override this with --lat/--lon/--alt, or force a local/engineering coordinate system with --local.

Adaptive Tile Hierarchy

DroneDB uses a face-count-driven heuristic to select the right tile hierarchy depth for each model, rather than a single one-size-fits-all tile configuration. Small models (<10K faces) produce a single tile at the finest level of detail, avoiding unnecessary build time. Large models get progressively deeper splits. The hierarchy depth is hard-capped at 6 (≤ 4096 finest-LOD tiles) so that no model, regardless of size, can produce an unbounded number of .b3dm files.

Model Size	Faces	Tile Hierarchy Depth	Max Tiles (finest LOD)
Tiny	< 10K	0	1
Small	10K–50K	1	4
Medium	50K–200K	2	16
Large	200K–750K	4	256
XL	750K–3M	5	1024
XXL	3M–12M	5	1024
Massive	> 12M	6 (capped)	4096

In debug/testing scenarios, you can skip the heuristic and force the default parameters:

# Skip adaptive sizing; use defaults (divisions=3, lods=3, octree=true)
ddb 3dtiles model.obj ./3dtiles --force-defaults

Ingesting a .3tz archive

Add a .3tz file to a DroneDB index like any other file:

ddb add my-tileset.3tz

# Build extracts the archive and prepares it for streaming
ddb build

During build, the .3tz archive is extracted into build/{hash}/3dtiles/ and validated to ensure tileset.json is present at the archive root.

In Hub / Registry

3D Tiles are rendered by the unified 3D viewer (powered by giro3d):

• Progressive streaming: Tiles load at multiple levels of detail based on camera distance.
• Georeferenced placement: Georeferenced tilesets are placed on the Earth ellipsoid (ECEF).
• Unified viewer: The same viewer handles 3D Tiles, Gaussian Splats, point clouds, and rasters.

Build requirements

3D Tiles generation depends on the Obj2Tiles binary from OpenDroneMap. The DroneDB build scripts attempt to download it automatically; see Building from Source for manual setup. If Obj2Tiles is unavailable, 3D Tiles generation is skipped and other artifacts (NXS, COPC, COG, etc.) still complete normally.