Creating a unified basemap from terrain, imagery and 3D Tiles in Cesium ion

Hi all,

I’m currently exploring workflows with Cesium ion (both cloud and on-prem) and I would like to better understand what is technically supported when building custom basemaps.

Our goal is to create a unified basemap that combines:

  • Custom terrain (from DEM / GeoTIFF)

  • Custom imagery (orthophotos)

  • Local 3D content (3D Tiles generated from FBX/GLB)

From our tests so far:

  • We can generate terrain from DEM without issues

  • We can upload 3D models and convert them to 3D Tiles

  • We can visualize terrain, imagery and 3D Tiles together in a viewer

However, what is not clear to us is whether it is possible to go beyond visual composition and actually:

  1. Merge multiple datasets (terrain, imagery, 3D Tiles) into a single asset that behaves as a basemap

  2. Use 3D Tiles directly as terrain (we’ve seen references to Cesium3DTilesTerrainProvider, but it seems experimental)

  3. Patch or override parts of an existing terrain (e.g. replace a specific area with higher resolution data)

  4. Programmatically generate a new terrain or tileset by combining multiple sources (using ion APIs or tools like 3d-tiles-tools)

In short:
:backhand_index_pointing_right: Is there any supported workflow to create a “fused” basemap asset, or is the recommended approach always to keep terrain, imagery and 3D Tiles as separate layers and compose them at runtime?

Any guidance, best practices, or pointers to documentation would be greatly appreciated.

Thanks!