Image tiles are not rendered completely

[Brakebein]

Describe the bug
When generating a 3D model, the texture contains a lot of black areas.
However, this issue doesn't occur with satellite imagery (MapBox-Satellite, Esri.WorldImagery), but with all the non-satellite imagery providers, e.g. ThunderForest-Outdoors, MapBox-Streets, Stamen-Toner, etc.
It seems that the downloaded image tiles are not processed correctly.
I tested it for different regions and with low, medium, and high image quality settings.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://elevationapi.com/playground_3dbbox
2. Select an area
3. For Imagery Provider, select "ThunderForest-Outdoors" or any other non-satellite imagery provider
4. Click on 'Generate 3D model'
5. See texture of generated 3D model

Expected behavior
A rendered texture without black areas.

Screenshots

Desktop (please complete the following information):

• OS: Windows 10
• Browser: Chrome 104, Firefox 103

Additional context
When choosing some imagery providers, e.g. "MapBox-Outdoors", error code Response status code does not indicate success: 410 (Gone). gets returned.

[xfischer]

Hi @Brakebein sorry for the late reply. I think it's an issue about multithreading still done in a poor way.
I will have a look.