Affects Version/s: 1.15.1, 1.15.2, 20w06a, 20w18a, 20w20b, 20w22a, 1.16 Pre-release 3, 1.16.2
Fix Version/s: None
In some rare cases, sky light can remain after breaking a block.
All steps are also demonstrated in the showcase.mp4 video.
- Get a flat surface at a sub chunk. A superflat world with only the first 16 blocks works great.
- Make sure no blocks are in this subchunk or in the neighboring subchunks at the same level or higher.
- Place a solid block with one air block between the surface. This is shown in "picture-1.png".
- After removing this block, notice that the darker light level remains. See "picture-2.png". This is more clear with "Smooth Lighting: OFF", which you can see in "picture-3.png".
- Now place a block directly on top of the surface, and place a solid block with an air block between the surface near it. This is the setup shown in "picture-4.png".
- Removing this block, the light level updates correctly. See "picture-5.png"
The exact place that surrounding blocks affect whether or not the sky light is updated, is unclear to me. There is also a zone where having blocks won't update the skylight, but replacing blocks in that zone will update the skylight.