Display glitch?

[Enkidu]

Minetest-5.6.0-dev-ec9f157 (server)
Minetest-5.6.0-dev-ec9f157 (client)
Running on Ubuntu 22.04

So, I'm deep (>1024) in a large cavern. In the distance, across the cavern there are lighted areas, blue in colour, like I can see the sky! When it is night outside I can see the stars. I can see the moon pass across a lighted area. These lighted areas seem to be openings to further reaches of the cavern.

In addition, when I look into a nearby dark or dimly lit area I see little sparkles.

This seems to have come on fairly recently, but doesn't seem to be related to any particular update. (I update and compile every week or so.) Does anyone know what is going on here? I'll try to attach a couple of screenshots, but I'm unsure if that will work.

[GayJesus]

same problem i've had for a long time. can be used as a cheat if you turn your view distance down to see players through stuff far away on PVP.

[Festus1965]

yes, you see the sky, as your client has (still) not loaded further other solid rock, and so can't show it = show sky behind. normal ...

[Enkidu]

@Festus1965 It was not always this way. At one time I would see a bright grey-white patch which would fade away. It doesn't fase away now. Are you saying that there is no solution?

[TenPlus1]

I change the skybox to black when below -100 so this doesnt happen.

[Enkidu]

I change the skybox to black when below -100 so this doesnt happen.

I see. Where do I set that? I don't know much about the innards of MT. Thanks

[TenPlus1]

You could use Sofar's SkyBox mod to create and set an underground skybox for when you are digging: https://content.minetest.net/packages/sofar/skybox/

..or..

The Other Worlds mod adds an asteroid layer which uses it's own skyboxes and the underground one is already set to black for you: https://notabug.org/TenPlus1/other_worlds

[Enkidu]

You could use Sofar's SkyBox mod to create and set an underground skybox for when you are digging: https://content.minetest.net/packages/sofar/skybox/

Thanks. I'll look into that.

What puzzles me is why this has suddenly started happening. These bright areas used to disappear after a second or two, but now they stay there for ever.

I checked the git log for the last week or so, but nothing sticks out.

[Enkidu]

Update:

I discovered that my Minetest server script was not bringing the server down. Having fixed that, so that the server and client are at exactly the same version, the problem seems to have been ameliorated. It hasn't been completely fixed, though. The version were never very different, so it's a bit odd.

I'll continue to update the server and the client every week or so, and hope that the issue goes away completely. If I find out what is causing this I will update this topic.