Projecting tileset on ellipsoid instead of on a plan.

I am programmatically generating a GLTF file to represent clouds. Instead of implementing each cloud with its own index and vertex buffer, I am simply applying a transform to multiple nodes, each applying the same mesh. I upload the data to Cesium Ion and it generates a tileset. I have attached a screenshot showing how it looks.

  1. Since the co-ordinate system is XYZ, naturally it will be a plane. How do I project this on to the Earth’s surface? The Z value for each tile is the altitude above sea level.

  2. If I wanted to have batch table attached to this so I can get data per each node of the GLTF, will I have to create my own B3DM? At the moment, I have a GLTF with BATCHID properly implemented (here I am not using the node approach - I am generating a large mesh). But I would like to use Cesium’s tiler to generate and host the tileset.