CityGML support for the PLATEAU project in Japan

Cesium ion
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The Ministry of Land, Infrastructure, Transport and Tourism of Japan is working on a 3D city model development project called the PLATEAU project.
The PLATEAU project develops data in CityGML format and makes it open data.
When uploading this CityGML to Cesium ion, an error occurs.
After investigating, we have confirmed that the CityGML developed by the PLATEAU project can be loaded into Cesium ion by:

  1. Reverse the latitude and longitude
  2. Exclude grp:CityObjectGroup *This mainly applies to LOD4 models of buildings and underground malls

For this reason, could you please improve Cesium ion so that PLATEAU-compatible CityGML can be imported?

・Standard Data Product Specification for 3D City Model

・opendeta

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Cesium distributes Japan 3D Buildings, but PLATEAU data also includes roads, urban facilities, vegetation, and underground shopping malls, and there has been a demand from users to incorporate this data independently using Cesium ion.

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Cesium does offer pre-tiled data that was created from the PLATEAU buildings data. The data set is described in Japan 3D Buildings – Cesium and was announced in the blog post at https://cesium.com/blog/2024/06/03/japan-3d-buildings/ . The data has recently been updated to include information about bridges that can be found in the CityGML data. This update is described in the blog post at https://cesium.com/blog/2024/10/24/updates-to-japan-3d-content/

Tiling this data required some manual work and curation. It is not yet possible to simply upload all of the PLATEAU data and tile it in one, automated pass. Longer term, it may be possible for end-users to tile certain parts of the PLATEAU data via ion. There is no specific timeline for this, but users will be informed with blog posts and forum threads about any updates here.

In the meantime, mentioning which aspects of the PLATEAU data you’d like to process or see included in the preprocessed data that is available on Cesium ion can help to properly prioritize the tasks both for the preprocessed data as well as for the ion tiling functionality.

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Thank you for your comment. I will check with people who actually use it.

1 Like
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Hi @Marco13 @Dave_Braig
I had a chance to talk with @takuya_danjo today. Unfortunately, they have not found the solution to this topic yet. I would add the explanation of the background on behalf of @takuya_danjo as below.
According to them, the project doesn’t allow to use Japan 3D Buildings because the project specification has been already agreed and engaged before the release of Japan 3D Building.
Therefore they still have to seek the way to upload CityGML data to Cesium ion. And they also need not only 3D Building data but also the following data to upload on Cesium.

Road, Urban Facilities, Vegetation,Urban Planning Decision Information, Railway, Pedestrian Path,Plaza,Navigation Route (or Waterway, depending on context), Bridge ,Tunnel, Underground Installations, Underground Arcade (or Underground Mall), Water Body, Zone, and Other structures which PLATEAU data has.

And they said they can not proceed with this project which requires uploading the PLATEAU CityGML data on Cesium ion without solving this issue because they can’t afford to manually adjust this issue every time when they or their customer needs to upload the new data.
Is it possible for you to provide further advise like confirming some information on lat/long, and/or on the useful information based on the knowledge from handling PLATEAU data so far.

@takuya_danjo Please add any information on project background or correct if the above explanation is wrong.

Thank you.
//

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@Gen_Kukita, @takuya_danjo thank you for sharing this additional information. The PLATEAU data is very valuable, and I understand the need to make it more accessible. This is a primary reason Cesium curated the Japan 3D Buildings and Terrain data.

When building the Japan 3D Building dataset we encountered many challenges in processing the source data including the reversed coordinates. In general, we followed these steps:

  • Manually identify each of the 200+ CityGML files to be downloaded by location and version (most recent)
  • Process the zip files to extract the buildings and bridge data and removing duplicate structures to generate a single dataset.
  • Tile the single dataset with a custom tiling process which accounts for the reversed longitude and latitude information in the CityGML data.
    • There is a specific GDAL Flag that needs to be accounted to address the reversed coordinates when tiling the CityGML data.

As @Marco13 mentioned, currently it is not possible to simply upload some of the PLATEAU CityGML data directly to ion. The team is looking into how best to incorporate updates to address the reversed values in the CityGML data as part of a standard upload to Cesium ion. There is no specific timeline for this, but we will be sure to keep you informed about any updates.