I am running this command to convert las file to cesium points cloud tiles:
py3dtiles convert mypointcloud.las --out cesiumtiles/output
This generates tile data, and I upload it to cesium ion viewer.
But rendered data is displayed for a moment only, and then goes away.
Is it an issue with generated tile data or cesium renderer?
Or is it related to projection systems? I am not sure which SRIDs I need to have.
Maintainer of py3dtiles here. Without seeing a video of what is happening, it's difficult to know for sure, but what you describe is often a symptom of a badly positioned pointcloud, for instance very far the surface of the globe.
When you load the pointcloud, you make your camera zoom to it, but then the camera control change the camera back to a position above the globe. Cesium controls are not ideal for an arbitrary view, they are tailored for the Globe.
Why it is badly positioned? Cesium scene are in the EPSG:4978 CRS, but usually pointclouds don't come in this system. This issue is so common that we have a full FAQ entry for this. I encourage you to read it. In short, you can try to convert it with the --srs_out 4978 parameter, so that it is transformed during the conversion.