Uploading Multi-Block Mesh Models from UAS photogrammetry

Cesium ion
1

Dear Team Cesium,

Using UAS for aerial mapping, I am generating high resolution mesh models of large sites predominantly using DJI Terra. Typically I am generating both .OBJ or .B3DM (aka “the most suitable for display in Cesium”, according to DJI Terra itself).

When generating B3DM mesh models, multiple blocks (with their own folder) are created, each containing many small .b3dm files and a few json. In addition a tileset.json file is created to help tie these together.

When generating OBJ mesh models, the folder hierarchy is similar but now each contain a single OBJ model and a series of tiled JPG texture images; in addition to a metadata.xml file to tie these together.

Having zipped and uploaded both to my Cesium Ion account, “something went wrong with this asset” so I am wondering where I am going wrong with regards to uploading these / selecting the correct parameters.

Could CRS projection be the issue, as this currently EPSG:27700 / OSGB1936 British National Grid?

Many thanks in advance for your help.

Kind regards,
Paul

The asset ID for the OBJ asset is 2842595.

2

Hi Paul,

It sounds like DJI Terra is trying to export pre-tiled data. I looked at the asset you provided and i has a metadata XML file which we don’t support for tiled data.

There are two you can try importing this data:

  1. Export a single OBJ mesh and upload to Cesium ion using the 3D Capture settings. Cesium ion will tile the data for you.
  2. Export a 3D tileset (tileset.json + B3DM) and upload to Cesium ion using the 3D Tiles setting. Cesium ion will host the tileset generated by DJI Terra

Please let us if either of those works for you.

Regards
-Mark