Draco compression about pg2b3dm HOT 2 CLOSED

One method to compress b3dm with Draco is a combination of existing npm tools 3d-tiles-tools and gltf-pipeline.

Procedure:

• Unpack b3dm to glb

• Compress glb with Draco

• Pack glb to b3dm

In code:

$ 3d-tiles-tools b3dmToGlb -i 1.b3dm -o 1.glb
$ gltf-pipeline -i 1.glb -o 1.glb -d -b
$ 3d-tiles-tools GlbToB3dm -i 1_draco.glb -o 1_draco.b3dm

In the library used for creating glTF's (SharpGLTF) there is no support (yet) for Draco compression.

Results first test with 3d-tiles-tools / gltf-pipeline:

• Compression is a factor of 6 to 10 (for example 1.b3dm goes from 800KB to 81 KB);

• Compression takes some time: a few seconds per tile;

• Test in Cesium 1.57: Draco compressed tiles are working, impression its drawing faster, fps in both cases roughly the same (15 - 30 fps).

Concern:

• Extra information in b3dm (like batch info) might get lost using this method.

Todo:

• Write script/docker tool to compress all b3dm's in current directory

from pg2b3dm.

Experimental 3D Tile Draco compressor is created at https://github.com/bertt/compressor5000 . It uses gltf-pipeline to create Draco glTF's.

from pg2b3dm.