How to convert 3d tiles file into other form?

Is it possible to convert 3d tiles file into other form? like .obj or .dae?

**Or can **3d tiles file be modified?

**Further more, is there any chance that **3d tiles and esri i3s will be compatible with each other?

I don’t know of a tool that currently converts 3D Tiles back into OBJ files. Is this something you need just to view your data in other programs or in order to edit it?

So far the workflow we’ve had is if you need to edit it, you’d edit the source data (the obj or the dae) and then re-tile tile. It would be very interesting to be able to edit the 3D Tiles directly, though. Perhaps as more people start to use 3D Tiles, more editing tools will support it. The 3d models are stored as glTF, so it should be possible to support this eventually.

I think 3D Tiles and i3s are two different standards, so I don’t think they’re compatible as different formats, but I think tools (like CesiumJS) could potentially support both formats if there’s demand for it so they can be loaded together in the same scene.

Hello Omar,

I’m trying to edit the 3D Tiles file, because on some occasion, the 3D Tiles file we got is not quite the way we want, and even worse we can’t find the original creator or the original model.So I wonder if there is any chance to directly modify the 3D Tiles file.

I think what most needed is a tool that can import 3d models like obj or dae file, with some basic edit and validate functions, then export into 3D Tiles.

More realistic and immediate maybe a tool that can read and modify the json file, like reset the bounding volume and the geometric error value. That is position, scale, and LOD.

For better knowing of 3D Tiles, my question are as follows:

Is there any formula or function to calculate those values?

I’ve seen this: https://github.com/AnalyticalGraphicsInc/3d-tiles/issues/162 ,in which @lilleyse says that geometricError doesn’t have an exact formula.So just manually designated a number of the size of a leaf node?

And the bounding volume like this?

var lon = 175.3050519951;

var lat = -41.1948830262;

var height = 0;

var location = Cesium.Cartesian3.fromDegrees(lon, lat, height);

console.log(Cesium.Transforms.eastNorthUpToFixedFrame(location));

How to split a huge model into many b3dm files in the first place? As I understand each b3dm file represent a leaf node?

I still don’t understand how does the 3D Tiles simplify the model at root level, Is it correct to think that 3D Tiles does not use something like Progressive Mesh or Vertex Clustering to simplify the model, it just split a huge model into many pieces to load when needed?

If that’s the case, how to handle a scene like your New York demo, a huge scene, thousands of buildings, without LOD, must be shown at the same and all time?

Thank you.

在 2019年1月10日星期四 UTC+8上午12:16:58,Omar Shehata写道:

How to split a huge model into many b3dm files in the first place? As I understand each b3dm file represent a leaf node?

That’s really the core problem Cesium ion tries to solve. Of course the answer depends on the source data, and finding the optimal tiling is something I know members of the team have spent a lot of time on.

I think for photogrammetry models it does simplify the model to create LODs. For something like New York I think smaller buildings are not loaded until the camera is closer. There’s some more info on the building tiler here:

I’m trying to edit the 3D Tiles file, because on some occasion, the 3D Tiles file we got is not quite the way we want, and even worse we can’t find the original creator or the original model.So I wonder if there is any chance to directly modify the 3D Tiles file.

I think a tool like that would have to recreate the source data by collecting all the leaf nodes, allowing you to edit, and then re-tiling it. Being able to re-tile tilesets like that is something on our radar, but there’s no timeline on it yet.

For now, most tilesets can be edited (in terms of rotation, translation and scale) using ion (just click on “Edit Tileset” in the top right when selecting your asset on https://cesium.com/ion/ )