Support tiling georeferenced 3D models into 3D Tiles

Cesium ion
4

Hello everyone,

I am wondering if there is any update on that matter ?

My team is using photogrammetric software such as RealityCapture and ContextCapture, that allows to automatically convert a model to b3dm format and to georeference it accurately in Cesium ion (this works well and we are using it).

The problem is that sometimes, we are postprocessing our models using Blender or alike, hence working with OBJ or COLLADA format, in local coordinates system (non WGS84).It would be very handy to be able to have them placed automatically on Cesium ion.

The georeferencing needs to be very accurate so the manual “adjust Tileset Location” is not suitable.
I tried to bind COLLADA models to a kml file according to this thread, the georeferencing seems to be working but, unfortunately, tiling to b3dm with the “KML/COLLADA” option does not retrieve a LOD that is satisfactory for large meshes. It seems that there is much less LOD generated compared to the “3D Models” upload option.

I also tested the CESIUM REST API mentioning the lat/lon/height of the model’s center but I am unsure on how to estimate the vertices center accurately enough and converting it to WGS84 (centroid, center of the bounding box ?)

Indeed having the option at the upload to read XML/text files to automatically place the model would be great. For information, here is an example of XML from ContextCapture:

 <?xml version="1.0" encoding="utf-8"?>
<ModelMetadata version="1">

	<!--Spatial Reference System-->
	<SRS>EPSG:2056</SRS>
	<!--Origin in Spatial Reference System-->
	<SRSOrigin>2532600,1152100,0</SRSOrigin>
	<Texture>
		<ColorSource>Visible</ColorSource>
	</Texture>

</ModelMetadata>

Is it something that is still investigated by Cesium ?