A proposal for a 3D Tiles packaging format specification

[javagl]

There have been several issues that asked about an archive/package format for 3D Tiles datasets (#89, #399, #422, and some issues in related repositories).

An early proposal for a packaging format was given in a comment in one of these issues, which described a format that is based on an SQLite database that just contains a table with a key (a "file name") and a content (a blob with the data of that "file"). Over the years, this format has become a "de facto" standard for tileset packages. This includes support via the tilesetToDatabase function in the 3d-tiles-tools repository. This still carries the note that the specification for the tables in the database is not final.

The following PDF file is an attempt to specify this format in more detail, including some technical constraints and implementation notes:

3DTilesPackageSpecification-1.0.0-2022-12-08.pdf

There are many discussion threads in the linked issues, about generalizing the keys, indexing, adding metadata, or different compression options. But for now, this document is mainly intended to capture something that could reasonably be called "version 1.0.0" of the packaging format specification.