We have a long-running branch—3d-tiles-terrain— that adds a new Cesium3DTilesTerrainProvider class. This is used for rending global 3D Tiles via the existing terrain engine.

This terrain provider supports only a subset of 3D tilesets (ie. 3D Tiles 1.1 with implicit tiling schemes matching that of terrain), so it may not quite ready for prime time yet. As such we should use the experimental tag to give us some flexibility if things need to change.

In the interest of maintenance as well as making this early work generally available, let's get this branch updated and merged into main. We'll also want to ensure the testing, documentation, and API structure are up to par as a part of this.