Note from [~GoldenHelmet]
The observed result is actually that the game begins to treat the location of the block light source (e.g. the spot the torch is in) as if it is a sky light source, even after you break the block light source. During daytime the location becomes brighter than a torch, and if you break the block light source at night you will see a low light level where there should be no light at all.
While building a mob spawner farm, I used tinted glass or sold blocks to darken the area. However, when I flicker the Redstone lamp and updated some blocks, the light source renders "overworld" lighting, making the cave too bright.
How to Reproduce
Locate a cave or another source of darkness.
Place any block that supports light. For example, place several torches.
Break or place several blocks near torches.
Destroy all torches.
Observed Results
When updating blocks, light sources nearby will render the area as if the user is standing on the surface. This means that it will increase the light levels much brighter than a torch or a glowstone.
Expected Results
Updating the blocks near a light source should not render the area as "overworld" surface light.
Linked issues
is duplicated by 6
MCPE-154462
Phantom/Too Bright Lights
Resolved
MCPE-154791
Skylight underground after updating/breaking light producing blocks
Resolved
MCPE-154968
Light issues, since 1.18.30
Resolved
MCPE-155138
Torches still emit light after I break them.
Resolved
MCPE-155437
Torches lights’ are broken.
Resolved
Attachments
Comments 7
This does not happen every time you break a light source underground. It seems to depend on location but I am not sure of the exact mechanic for that. It does not require relogging, reloading the chunk, or 2-player scenarios. I was able to reproduce after trying a few different spots in an enclosed box in a brand new world.
Most of the time you have to place a solid block in the position where the block light source was broken in order to remove the sky light:
[media]
However, this video seems to show the light levels in the blocks where the torch actually reached returning to 0 after destroying the torch while sky light remains one block farther away:
[media]I wonder if this is related to the fix for MCPE-151266? It seems that the block light source tries to update its light level whenever a solid block is placed nearby, but when doing so it incorrectly treats its location as being at the surface of the world.
Looks like this is more frequent when I’m lighting up dark caves and mining at the same time. Thanks for confirming this bug!
If you have a copy of the world available, you might like to upload a copy of it for investigation.
On Windows 10 you can use the Export world feature.
On Android or iOS you need to use a file explorer to navigate to Device storage > games > com.mojang > minecraftWorlds
On Xbox or Switch the only way is to upload it to a Realm, and then download the world on Windows 10 or Android/iOS. (Please do not purchase a Realms subscription just to provide a world to us - but if you have a Realm already this may be a viable option if you wish to do so.)
If the world is larger than 10MB you can upload the world to OneDrive or a similar file sharing site, and then share the link.
It does not depend on the world.
[media]shows me reproducing the bug in a brand new world with a random seed.
Same results in another new world with random seed:
[media]To reproduce:
Open the world.
Place a torch on the target.
Place a block anywhere else inside the box you are in.
Break the torch.
Place a block on the target, where the torch was (to reset any phantom skylight).
If all light goes away after breaking the torch, repeat steps (2) - (4) but placing the block in a different place.
Demo:
[media]
In most runs of these steps some sky light will remain somewhere in the room after step (4). You can verify that it is skylight by switching between night and day with commands.
Can you upload a video of this happening? Does this occur every time you break a light source underground?