iTwin RealityData Actor

[ckghd]

Hello,

I'm looking for some documentation or guide on how this actor works. We have pointcloud data loaded in our imodel. Is it possible to stream this into unreal from there?

Thanks,

Chris

[GhisBntly]

Hello,
I know cesium-unreal can display point clouds as there is a sample project (https://github.com/CesiumGS/cesium-unreal-samples/blob/main/README.md#cloud-level-11---point-clouds - streaming that from Ion I guess) but I don't know what the workflow is for an iTwin, I will ask my colleagues.
I'm not sure to understand, is your pointcloud data inside a dedicated iModel, or is it stored as a Reality data in your iTwin project?

[ckghd]

Hey,

Thanks for the reply. It's reality data in the iTwin project. We have the LAS files stored in a ProjectWise folder as well, but they are not included in the iModel.

I'll deconstruct the example, maybe there is something in there I am missing. :)

[GhisBntly]

Hello,
I had confirmation that the Reality Conversion Service can indeed convert Point Clouds to 3D tiles.
To use the Reality data actor in the plugin, you will need to set the ServerConnection property and the Reality data ID (maybe the iTwin Id too...?).
The only way to retrieve the Reality data Id that I am aware of is to use the developer api directly on https://developer.bentley.com/apis/reality-management/operations/get-all-reality-data/

• Click "Try it out",
• Select "authorizationCode" in the drop-down and complete the log-in process if needed:

• Fill the project Id (aka iTwin Id), and click "Execute"
• Once the server has replied, scroll down to the bottom of the window to see the json reply with the list of Reality data associated to the iTwin, for example (you will get the full IDs, I just masked part of it in my example with ************):

HTTP response
HTTP/1.1

200 OK

content-encoding: gzip
content-type: application/json; charset=utf-8
date: Thu, 04 Dec 2025 08:07:07 GMT
(...)

{
    "realityData": [{
        "id": "d534422b-f003-4938-95a7-************",
        "displayName": "Production_4_microsoft_3dtiles",
        "type": "Cesium3DTiles"
    }],
    "_links": {
        "next": null
    }
}

Hope this helps,

[GhisBntly]

I was just told of simpler way to get the ID: just go to https://connect-contextshare.bentley.com/, search for your Reality data by its name, and use the copy icon button in the "Id" column to the right to get the Reality data Id.

[ckghd]

Thanks! I am working on this trying to sort out our data. I can see my project but cannot see my reality capture data in the management tab. I can locate the project when I search but it tells me "Team members of projects who have reality management's use permission are allowed to consume the associated reality data." Good times lol Once I get that sorted I will let you know if i can get it to work.

[ckghd]

UPDATE. I got this working, sort of. I can see it in the outliner, but it does not spawn in the world. I think it also crashes the file... here is the error message:

Fatal error: [File:D:\build++UE5\Sync\Engine\Source\Runtime\Core\Private\Containers\ContainerHelpers.cpp] [Line: 8]
Trying to resize TArray to an invalid size of 2147483648

[GhisBntly]

Hello,
Thanks for the feedback - maybe it doesn't spawn in the right (geo-)location :-/

Strangely, I had the same crash error in ContainerHelpers.cpp last week and it was because I was trying to load content files (pak and related files though, not uassets) generated by UE 5.5 into UE 5.6.
Since the newly released plugin uses UE 5.5 and no longer 5.3, the coincidence is intriguing: are all your other use cases working with the new UE 5.5 plugin? (if you indeed updated to the latest version).

Maybe worth cleaning the Intermediate, DerivedDataCache and Saved subdirs from your project folder?
Although ContainerHelpers.cpp is very low level so the error could also be totally unrelated...

As a last resort, could you share the Reality data with us so we can test on our end?
Thanks,

[ckghd]

Thanks for your help. I cannot share this project data unfortunately. :( I will clean and let you know

[GhisBntly]

Hello,
I finally got around to testing loading a standalone Reality data model in the plugin, and I noticed that when I add the actor to the Unreal world, I get random coordinates for the actor's "Location": those need to be reset to zero to get the mesh at the right location. I realize those were visible in your capture, which I apparently failed to notice...
In any case, when you are in the Editor without running in "PIE" mode, you can select the cesium tileset actor (not the itwin reality data actor!) and hit the shortcut "F" to have it centered in the viewport (or right-click in the Outliner and choose "frame selected").

I mentioned geolocation but your capture also shows that your tileset is not geolocated, is that expected?

But more importantly for you, the crash certainly needs to be investigated. The error hints at a problem with handling a very large amount of data, as Unreal collections are limited to 2 billions elements (2**32).
Do you think your dataset indeed has more than 2 billions points in total?
What surprises me is that, by definition, the tileset should distribute those into more manageable tiles. Possibly there may be uncovered corner cases where a single tile would end up with more than 2B elements, maybe when there is a very high concentration of points in a comparatively small volume (compared to the overall tileset physical extent).

Any information that you may share about the number of points and the kind of spatial distribution in your tileset could be useful at this point: note that I have only tested a Reality data made of triangles so far, where the triangles are evenly distributed over the tileset's extent. I will ask for very large point dataset to test with, but your information could help the iTwin Capture team provide me with a tileset that best matches your use case.

[ckghd]

Hello,

I had been pulled in other directions and then a holiday break, so I apologize for the delay in getting back to this. Your first method of finding the Reality Data ID seems to work as I see the actor change to the correct / corresponding name but it does not spawn in the world. I also zeroed out the location as you mentioned. Any thoughts on this?

[GhisBntly]

Hello,
Have you tried the "F" shortcut in the Editor as mentioned in previous message, to see if the viewpoint is changed to some other place?
Is it expected that the tileset is not geolocated?

About the crash, I have still not been able to test a large point dataset, sorry :-/ I will ask again now that most colleagues are back from seasonal holidays :-)

[GhisBntly]

@ckghd , about the crash, we do not have a very large points dataset readily available, although we can easily generate one.
Before I ask a colleague to spend time on this, can you please confirm the approximate size of the dataset that crashed Unreal? (total number of LIDAR points, not a file size)
Thanks!

[ckghd]

Hello, Have you tried the "F" shortcut in the Editor as mentioned in previous message, to see if the viewpoint is changed to some other place? Is it expected that the tileset is not geolocated?

About the crash, I have still not been able to test a large point dataset, sorry :-/ I will ask again now that most colleagues are back from seasonal holidays :-)

@GhisBntly I am back from holidays as well ;) I have, regarding "F" The tileset is defiantly geolocated as I can see it in place on infrastructurecloud.bentley.com iModel.

regarding the crash, I cannot re-create it either so that must have been an anomaly

[ckghd]

@ckghd , about the crash, we do not have a very large points dataset readily available, although we can easily generate one. Before I ask a colleague to spend time on this, can you please confirm the approximate size of the dataset that crashed Unreal? (total number of LIDAR points, not a file size) Thanks!

As I mentioned in the other reply that I cannot create the crash so i think that was an anomaly, but I do see the correct actor being displayed in the outliner but it is not spawning in the VP.

[GhisBntly]

Hello @ckghd , hope you enjoyed the holidays :-)
Thanks for the feedback!
I would like to have a look at the plugin logs to see why the dataset's geolocation doesn't seem to be recognized/loaded, could you please share this file : %TEMP%\ITwinAdvViz\Logs\log_AdvViz-App.txt (send to ghislain dot cottat at bentley etc.)
NOTE that the file contains the IDs for the datasets loaded, but of course I will not have access to them, I just want to see if there were some errors related to geolocation.
Thanks,