Smooth lighting has completely broken for partial blocks as of 1.21.100. This was not an issue in 1.21.94. This change from the 1.21.100 changelog has most likely caused the issue:
Fixed faces of non-full blocks (eg. Cakes or Trapdoors) having an unnatural ambient occlusion applied to them in some neighboring blocks configurations
This has actually made lighting significantly worse for all non-full blocks. It is most noticeable on snow layers and village paths, since they are light in color and often surrounded by full blocks.
List of confirmed affected blocks:
All slabs
Snow layer
Dirt Path
Carpet
To Reproduce
In the main menu, navigate to Settings → Video → Graphics Mode, and select Fancy.
Enable Smooth Lighting.
Enter a world in Creative Mode with Cheats enabled.
Type the following command:
/locate biome minecraft:snowy_slopes
Teleport to the Snowy Slopes biome.
Observe a sloping hill with snow layers.
Observe the unnatural lighting on the snow layers.
Expected Result
Lighting is smooth on partial blocks when next to full blocks.
Observed Result
Lighting on partial blocks looks unnatural next to full blocks, with a harsh dividing line at the edge of the partial block.
I was exploring my city when I noticed that anytime there was an intersection in Dirt Paths, a strange light gradient/highlight was displayed on the Dirt Path block. Not a big issue but one that I think could be fixed.
Linked issues
is duplicated by 5
MCPE-226198
Strange shadow from blocks on snow
Resolved
MCPE-226227
Weird shadow shows on path blocks
Resolved
MCPE-226247
Smooth lighting on partial blocks is broken after 1.21.100
Resolved
MCPE-226478
carpet patterned in low light
Resolved
REALMS-13287
"Fancy" Shaders Look Worse Than Before
Resolved
I also encountered this issue and did some investigating to figure out why it’s happening. Here is a more thorough description of the issue:
Title: Smooth lighting on partial blocks is broken after 1.21.100
Description:
Smooth lighting has completely broken for partial blocks as of 1.21.100. This was not an issue in 1.21.94. This change from the 1.21.100 changelog has most likely caused the issue:
Fixed faces of non-full blocks (eg. Cakes or Trapdoors) having an unnatural ambient occlusion applied to them in some neighboring blocks configurations
This has actually made lighting significantly worse for all non-full blocks. It is most noticeable on snow layers and village paths, since they are light in color and often surrounded by full blocks.
List of confirmed affected blocks:
All slabs
Snow layer
Dirt Path
To Reproduce
In the main menu, navigate to Settings → Video → Graphics Mode, and select Fancy.
Enable Smooth Lighting.
Enter a world in Creative Mode with Cheats enabled.
Type the following command:
Teleport to the Snowy Slopes biome.
Observe a sloping hill with snow layers.
Observe the unnatural lighting on the snow layers.
Expected Result
Lighting is smooth on partial blocks when next to full blocks.
Observed Result
Lighting on partial blocks looks unnatural next to full blocks, with a harsh dividing line at the edge of the partial block.