CONTRIBUTING.md

Tile Format Spec Writing Guide

As we add more tile formats, 3D Tiles needs to stay consistent.

Terminology

• Tiles are composed of sections such as header and body. Sections are composed of fields such as magic and version.
• "Feature" - indicates one model in a batch of models (b3dm), one instance in a collection of instances (i3dm), one point in a point cloud (pnts), one polygon in a vector tile (vctr), etc.

Fields

• Field names are in camelCase.
• Length - a Length suffix on a field name indicates the number of elements in an array.
• ByteLength - a ByteLength suffix indicates the number of bytes, not to be confused with just Length.

Header

• Each tile format starts with a header that starts with the following fields:

magic            // uchar[4], indicates the tile format
version          // uint32,   1
byteLength       // uint32,   length, in bytes, of the entire tile.

Binary

• All binary data, e.g., tile formats, are in little endian.

Code of Conduct

To ensure an inclusive community, contributors and users in the Cesium community should follow the code of conduct.