I3S Scene Layers
I3S (Indexed 3D Scene Layers) is an OGC standard for streaming large 3D datasets over the web. It is the native format for ArcGIS Scene Services and is commonly used for city-scale 3D buildings, terrain meshes, and point clouds that are too large to load as a single file.
I3S layers stream directly from the server — only the tiles visible in your current view are loaded, so performance stays consistent even for very large datasets.
Adding an I3S layer
- In the Layers panel, click + Add Layer to open the Import Layer dialog.
- Select I3S Scene Layer as the layer type.
- Paste the I3S Scene Layer URL into the URL field. This URL typically ends with
/SceneServeror/SceneServer/layers/0. - Optionally, enter a Geoid terrain URL if the dataset uses a geoid-based vertical datum that needs correcting (see Vertical datum correction below).
- Click Add Layer.
The layer loads progressively — tiles appear as the viewer streams them from the server.
You can also ask GeoAI to add an I3S layer directly: "Add an I3S layer from https://tiles.arcgis.com/…/SceneServer"
Where to find I3S data
| Source | Notes |
|---|---|
| ArcGIS Online | Search for Scene Layers on ArcGIS Online. Open a Scene Layer item and copy the Scene Service URL |
| ArcGIS Enterprise | Your organisation's ArcGIS Enterprise portal — ask your GIS administrator for scene service URLs |
| National mapping agencies | Many national agencies publish city 3D models as I3S services |
| Any OGC I3S endpoint | Any server that implements the OGC I3S specification |
A valid I3S URL looks like:
https://tiles.arcgis.com/tiles/<org-id>/arcgis/rest/services/<service-name>/SceneServer
or with a layer index:
https://tiles.arcgis.com/tiles/<org-id>/arcgis/rest/services/<service-name>/SceneServer/layers/0
Automatic symbology
AugmentCity applies the symbology defined in the I3S service automatically. This means colours, materials, and visual styles set by the data publisher appear without any manual configuration. You do not need to restyle the layer unless you want to override the defaults.
Vertical datum correction
Some I3S datasets use a geoid-based vertical datum (for example, EGM96 or EGM2008) rather than the ellipsoidal heights that CesiumJS uses internally. Without correction, buildings may appear to float above or sink below the ground surface.
To fix this, enter a Geoid terrain URL when adding the layer. This is a URL to a quantized-mesh terrain service that encodes the geoid undulation. AugmentCity uses it to shift the I3S geometry to the correct elevation.
Most I3S datasets from ArcGIS Online do not need geoid correction — ArcGIS Online normalises vertical datums automatically. You are most likely to need this setting when connecting to I3S services from national mapping agencies that publish data in local vertical datums.
If you are unsure whether your data needs geoid correction, add the layer without a geoid URL first. If buildings look correctly placed on the terrain, no correction is needed.
Layer panel
I3S Scene Layers appear in the 3D Tileset category in the Layers panel, shown with a building icon and labelled I3S Scene Layer.
The following standard layer controls are available:
| Control | Description |
|---|---|
| Visibility toggle | Show or hide the layer |
| Opacity | Adjust layer transparency from 0% to 100% |
| Zoom to | Fly the camera to the layer's extent |
| Delete | Remove the layer from the project |
Scenarios and split view
I3S layers are fully scenario-aware. Visibility and opacity settings are saved as part of the scenario snapshot and restored when you switch scenarios.
I3S layers also support Split View — you can compare an I3S layer against other data using the swipe compare tool. See Split View for details.
Performance tips
- I3S layers stream tiles on demand. The viewer prioritises tiles close to the camera, so flying to a new area may show a brief loading period as tiles arrive.
- If the dataset is very dense (for example, a city-wide photogrammetry capture), zoom in to a specific area rather than viewing the full extent at once.
- Reducing the opacity of other layers can make it easier to inspect I3S geometry in dense scenes.