Clouds near the horizon disappear when the camera enters the cloud layer. Rays should continue tracing after exiting and re-entering. This works correctly with alternate mode Tracing Max Distance Mode: Distance from Point of View.
Clouds below the planet’s atmospheric bottom boundary should be clipped, as the planet occludes them. Instead, they remain visible and can cause bright Skylight artifacts, especially at sunset.
In Tracing Max Distance Mode: Distance from Point of View mode, rays can re-enter the cloud layer, but UpdateMaterialCloudParam still samples the conservative density material while outside the cloud hull. Skipping directly to the re-entry point could avoid these unnecessary samples. Ideally, the default tracing mode should also support re-entry.
Screenshot 1 just below the cloud layer showing clouds beyond the planetary horizon remain visible:
Distance from point of view traces up to the specified TracingMaxDistance from the point of view. You have to tweak the view distance.
Distance From Cloud Layer Entry Point: this other mode trace from the first entry point traced from the camera up to the first exit point as I recall. That is an optimisation for point of view on the ground: only spend the tracing sample budget from the entry point into the cloud layer to the exit point. With TracingMaxDistance being the largest distance which in this case can be lower. Re-entry is not supported: that is why the Distance from point of view mode was added. If the camera is inside the later, the tracing will be from camera to first exit point, and so due to curvature some clouds can disappear. We do not trace twice.
It seems that you will have to use the Distance from point of view mode then.
