3D tiles confusion

CesiumJS
1

Hey all,

I’m a little confused as to weather or not I’ve done 3D tiling correctly, as during my work I’ve split a 250MB+ test 3D model of a castle into 50 different tiles. Each tile is its own .b3dm file, with a feature table so that it can be styled. The tile spec defines the structure of the tiles as a quad tree. However now I’ve split the model into these tiles, the load times have increased and the overall download has too. The tiles together, have an overall size of 318MB+, also there are more requests to the server, due to each tile being downloaded as I zoom into the model and navigate it. Also due to the size of each tile, I can zoom in and navigate the model before the tiles pop in/replace or add to the level of detail.

Therefore I was wondering if there was anyway to convert all the tiles into a single file, weather or not I need more or less tiles, or any advice in general in how to tile a very, very large singular 3D model…

Thanks for all the help and advice.

2

Hey again,

So really the best approach for a model like that is to use replacement refinement and have more simplified models at higher levels of the tree. That way the highest res / largest MB tiles don’t all need to be downloaded unless required. It also would avoid tiles popping in in favor of noticeable level-of-detail shifts. It sounds like your approach is more additive refinement based…?

The model simplification can be tricky though, the decimate modifier in Blender is pretty good. Using an octree data structure is probably a good way to go to start.

Overall I would recommend going with the more tiles approach. Are you using any textures? If that is adding to the tileset bloat the tiles could all reference the same external texture file.