MCPE-52887Lighting error causes sky light in cave
A bottom slab, stair, or leaves placed on the surface updates solid opaque blocks below it to be lit by the sky light level. This is normal for the block immediately below it, but the effect is propagated downward until an air block is reached. This causes any cave beneath one of these blocks to be lit as if it were exposed to the sky. The effect is reset when something causes light to be recalculated, such as unloading and reloading the chunk, or reset for any single solid block if it is broken and replaced. The effect is not reset by breaking the slab, stair, or leaves, including if you replace them with solid opaque blocks.
This bug makes it possible to temporarily light up a cave by placing slabs or stairs on the surface above it.
Steps to reproduce:
- Find a dark spot in a cave below the surface with no other cave above it.
- Note the coordinates of a block in the dark space.
- On the surface, place a bottom slab, stair, or leaves at the corresponding X/Z coordinates.
- Return to the spot in the cave.
Expected results:
The cave is still dark.
Actual results:
The cave appears lit by skylight at the ceiling block with those X/Z coordinates. If you break the ceiling block, it will still be lit by the block above it. If you replace the broken block, the cave goes dark again.
The fix for MCPE-41273 may have caused this issue.
Linked Issues
is duplicated by1
Attachments1
![[Mod] LateLag](../../../data/avatars/users/92884.png){kind=small}
![[MCPE Mod] Auldrick](../../../data/avatars/users/10122.svg){kind=small}
Created Issue:
Lighting error causes sky light in cave
A bottom slab, stair, or leaves placed on the surface updates solid opaque blocks below it to be lit by the sky light level. This is normal for the block immediately below it, but the effect is propagated downward until an air block is reached. This causes any cave beneath one of these blocks to be lit as if it were exposed to the sky. The effect is reset when something causes light to be recalculated, such as unloading and reloading the chunk, or reset for any single solid block if it is broken and replaced. The effect is not reset by breaking the slab, stair, or leaves, including if you replace them with solid opaque blocks.
This bug makes it possible to temporarily light up a cave by placing slabs or stairs on the surface above it.
Steps to reproduce:
- Find a dark spot in a cave below the surface with no other cave above it.
- Note the coordinates of a block in the dark space.
- On the surface, place a bottom slab, stair, or leaves at the corresponding X/Z coordinates.
- Return to the spot in the cave.
Expected results:
The cave is still dark.Actual results:
The cave appears lit by skylight at the ceiling block with those X/Z coordinates. If you break the ceiling block, it will still be lit by the block above it. If you replace the broken block, the cave goes dark again.
A bottom slab, stair, or leaves placed on the surface updates solid opaque blocks below it to be lit by the sky light level. This is normal for the block immediately below it, but the effect is propagated downward until an air block is reached. This causes any cave beneath one of these blocks to be lit as if it were exposed to the sky. The effect is reset when something causes light to be recalculated, such as unloading and reloading the chunk, or reset for any single solid block if it is broken and replaced. The effect is not reset by breaking the slab, stair, or leaves, including if you replace them with solid opaque blocks.
This bug makes it possible to temporarily light up a cave by placing slabs or stairs on the surface above it.
Steps to reproduce:
- Find a dark spot in a cave below the surface with no other cave above it.
- Note the coordinates of a block in the dark space.
- On the surface, place a bottom slab, stair, or leaves at the corresponding X/Z coordinates.
- Return to the spot in the cave.
Expected results:
The cave is still dark.Actual results:
The cave appears lit by skylight at the ceiling block with those X/Z coordinates. If you break the ceiling block, it will still be lit by the block above it. If you replace the broken block, the cave goes dark again.The fix for
MCPE-41273may have caused this issue.
relates to
![[Mojang] Mega_Spud (Jay Wells)](../../../data/avatars/users/92696.png){kind=small}
is duplicated by
After studying the lighting problem, I realize now that it was that that give the appearance of this bug being fixed, and also caused no monsters to spawn after stairs were placed on the surface above my spawn floor at Y=6.
This bug is not fixed! When I placed stairs above the spawn floor, nothing spawned (because of MCPE-52887), but after I reloaded the world monsters started spawning again (because it caused all lighting to be recalculated). And the monsters that spawned were once again tagged as surface mobs. Note that MCPE-52887 makes this look like it's fixed, until you unload and reload the world after placing stairs on the surface.
Though the symptom is described a little differently (kind of the reverse), I believe this is the same bug as reported in MCPE-52887. That bug was fixed in the 1.13.0 release. Are you still experiencing this issue?
Relinked as a duplicate of MCPE-52887 because of similar symptoms and range of dates.
Could confirm. Attached screenshot as well.
A video clip that may provide more information: https://1drv.ms/v/s!Agfpi9lElwxOgcsBYcf0Xq6kO1x4OQ?e=5Eeq3S [edit: replaced with a better clip]
This was in a world that was upgraded from 1.12. It's the same world the attached screenshot was taken in. This is a fresh section of an ocean floor; I had never placed any blocks in or above the ocean here, yet the stone below the sand becomes brightly lit after I place sand on it, even though the ocean is dimming the light before my changes.