Licensing options for this format begin with FME Desktop Professional Edition.
The Cesium 3D Tiles Writer allows FME to write large 3D datasets for use in the Cesium virtual globe environment. For more information on Cesium, see https://cesiumjs.org/.
The 3D Tiles format allows Cesium to efficiently display very large datasets of 3D objects, such as an entire city. The dataset is divided into a hierarchy of tiles, and Cesium will only render tiles that are visible from the current viewpoint.
A 3D Tiles dataset consists of a single JSON file, tileset.json, which outlines the tile structure of the 3D dataset. Each tile will refer to additional files that contain features, attributes and geometries and textures.
Writer Overview
The Cesium 3D Tiles writer produces a separate tileset for each FME feature type. All features with a single feature type will be part of the same 3D scene.
The writer will assemble a hierarchy of tiles; each tile will contain a number of features. Features that are close together will generally be in the same tile. This allows Cesium to render the dataset more efficiently by minimizing the number of tiles that need to be loaded in memory at the same time.
Cesium will selectively render tiles based on the zoom level of the current view. Tiles that are closer to the bottom of the tile hierarchy may not be rendered until the view is zoomed in closer to the tile location. The cesium_priority attribute can be used to set the relative positions of features within the tile hierarchy. Features with a higher priority value will be closer to the top of the tile hierarchy, and therefore be rendered at higher zoom levels than features with a lower priority. The value of this attribute can be any floating point number. Features without a value will be assigned a priority of 0.