The National Geospatial-Intelligence Agency (NGA) partners with Vricon to distribute high-resolution 3D surface models. These are distributed as 3D Tiles (.t3z/.b3dm extension) for use with Cesium-based viewers and as Indexed 3D Scene (.slpk extension) for compatibility with Esri products. The .slpk files can be added to both Earth and Earth Mobile - and while the scene renders with elevations - the files cannot be added as Terrain files. As a result, other data cannot be draped on top of the .slpk. The use case that frustrates me the most is that I cannot draw lines/routes draped on the .slpk.
