Reality Capture/Reality Scan LOD Export Settings

Cesium ion
1

Hello,

I am in need of your expertise regarding the ideal level of detail export settings from reality capture for cesium ion streaming.

The model sizes range from 2-10M tris and 20-65 parts. The current issues are:

Gray/untextured polygons in the model (sometimes these go away when zooming/sometimes not), extremely deformed geometry when at medium distance, (this fixes once zooming in).

I have tried sharing straight to cesium from Reality Capture/Reality Scan and get the second issue.

when I do an Level of Detail export , depending on settings I get either error.

At this point I have exported at least 40 different times at different settings to find a solution. I am eagerly awaiting your direction!

Thank you!

2

Hey,

I apologize that you are running into errors with your export. Are there asset ids for some samples that you have uploaded that we can take a look at? We don’t currently have specific recommendations for export. But taking a look at the source data you are uploading would help us provide the most helpful recommendation to you.

Thanks,
Ankit

3

Hi Ankit, Please see the asset ID: 4101475, 4094926, and 4101452. These are all having quality issues. Thank you!
4

Hi,

I have forwarded these ids to our tiling team to investigate. I will reach back out to you as soon as I have an update.

Thanks,
Ankit

5

Hi,

Following up on my previous email, it looks like the source type is 3D Tiles for the data you are uploading. When uploading data as 3D Tiles, Cesium ion doesn’t process the data and only hosts it for streaming. Since this data is exported from Reality Scan, we can’t comment on how to increase the quality of the output.

Instead of doing an LOD export from the software, I would recommend trying to export the models as an obj mesh and uploading that to Cesium ion. Based on the data, I would pick the 3D_CAPTURE option when uploading the obj. This will allow the Cesium ion tilers to process the data and convert them to 3D Tiles for LOD streaming.

Thanks,
Ankit

6

Hi Ankit,

Thank you for the solution, it works a lot better, however, I am still getting the deformed geometry.

I recently created asset: 4508037 and am getting the same issue.

Could I send you the export data privately?

Thank you!
7

Hi Jogilles,

I looked at that asset. I did notice some small deformations when the geometry was far away from the camera. They would resolve when the camera got closes and a higher level of detail was loaded.

Is this what you were seeing? If so you can set tileset.maximumScreenSpaceError to a lower value (eg 8 instead of the default 16) to load the higher level of detail sooner. This will let you use the existing tileset while we investigate further.

If this is not what you are seeing you can send a message to support@cesium.com and reference this thread. Please make sure to include:

  • Screenshots of the deformed geometry in the 3D tileset vs the original geometry.
  • Let us know where that geometry is located in the overall model so we can locate it. Our engineers will not be as famialar with the data as you are.

Either way please let us so we look into this further.