failed tiling model

CesiumJS
1

I am working for a project of Municipality where we have to implement for them a city model and publish it in the same way of what you show in below link “:

https://cesiumjs.org/Cesium/Build/Apps/Sandcastle/gallery/3D%20Tiles%20Feature%20Picking.html

the method we are using is to create DTM and aerial imagery from drones with 4 cm resolution, - creating topo surface and buildings in Autodesk infraworks – exporting separate OBJ or FBX files – Using FME to create Cesium Tiles

after several weeks of intensive trials we managed to create a cesium tiles of small zone which contains 20 buildings / 2000 Trees / furniture’s , the total size of the OBJ files where around 9 GB and the total Tilset where around 4 GB, we managed to create 4 Tiles for each feature ( Ground / Trees / Furniture’s / Buildings )

but I admit that trial was not successful, I was searching all the forums trying to solve our issue without any progress.

Our problem specified in next :
• There is 1 b3dm file for each feature which means its loading all the features at once , the database not tiled so it cannot load partial data on each zoom level
• We cannot integrate database with models, I couldn’t find a way to separate models and feed information to it.
• I was comparing the data exported from obj23dtiles To the data from Context capture mesh model, the context capture creating mini tile for each feature which helps Cesium to read LOD layers, but never succeed in FME conversion or any other.

is there any guidance that guide how to make a project from A To Z , such as : converting OBJ files to tileset including coordinate system conversion and intelligent data feeding ? i assume this achievable but tiling the project and make it small B3dm files ?

2

Have you looked at using Cesium Ion to do the tiling?
You upload obj file and it generates all the LoD b3dm files.

3

Thank you for quick answer

Yes indeed I tried it, but next points recorded :

· placing models on the exact location was not accurate enough, in our method we used an accurate locations .

· the colors were lost when using OBJ format ( seems Ion Did not read the Mtl file)

· I couldn’t see a way to do Model tiling then to download the tileset to be used offline , is there a way to do that ?

· Cesium Ion is paid hosting service, will it allow for data conversion and offline usage ? in case I need to store models in our server ?

Thanks for Support

4

Hey Walid,

For tiling and then downloading, this isn’t possible on ion, but if you’re interested in offline use we do have on-premise tools:

Which are also paid and you can access them by talking to Tim (tim@cesium.com). Those might be useful for you to check out especially if you’re interested in being able to host your tilesets yourself.

I see there are some issues with uploading OBJ files on ion in the community repo (https://github.com/AnalyticalGraphicsInc/cesium-ion-community/issues). Like this issue. Feel free to make a comment there as well for your OBJ specific issues or see if the discussion there helps at all.

On the location issue, I believe ion lets you specify longitude and latitude for your tilesets. Can you elaborate a bit more on what you mean by not accurate enough? It’s a new tool and we definitely appreciate getting feedback on it from different use cases.