We have mostly been working on the generation of Mapbox Vector Tiles from OSM data. It would be interesting to try the new 3d tiles specification.

We can use JTS to create tessellations Delaunay Triangulation.

We can use Jgltf to generate GLTF data.

Finally we can render the 3d tiles directly with Cesium.

For anyone interested in getting started with 3d tiles and GLTF, I recommend the following links:

• Read all the 6 resources listed on this page https://cesium.com/why-cesium/3d-tiles/
• Read the reference card for GLTF here https://github.com/KhronosGroup/glTF