[MC-3961] Water, Cobwebs, Magma, Leaves and other blocks save sunlight Created: 29/Nov/12  Updated: 23/Oct/18  Resolved: 23/Oct/18

Status: Resolved
Project: Minecraft: Java Edition
Component/s: None
Affects Version/s: Minecraft 1.4.5, Minecraft 1.4.7, Snapshot 13w05b, Minecraft 1.5, Snapshot 13w11a, Minecraft 1.7.5, Minecraft 14w11b, Minecraft 14w21b, Minecraft 1.7.10, Minecraft 14w28a, Minecraft 14w28b, Minecraft 1.8, Minecraft 1.8.1-pre3, Minecraft 1.8.1, Minecraft 1.8.2-pre6, Minecraft 15w38b, Minecraft 15w47c, Minecraft 1.9 Pre-Release 1, Minecraft 1.10, Minecraft 1.10.2, Minecraft 16w32a, Minecraft 16w32b, Minecraft 16w33a, Minecraft 16w35a, Minecraft 16w44a, Minecraft 1.11.2, Minecraft 17w06a, Minecraft 17w13a, Minecraft 17w13b, Minecraft 17w14a, Minecraft 17w15a, Minecraft 17w16a, Minecraft 17w17b, Minecraft 17w18a, Minecraft 17w18b, Minecraft 1.12 Pre-Release 1, Minecraft 1.12 Pre-Release 2, Minecraft 1.12 Pre-Release 3, Minecraft 1.12 Pre-Release 4, Minecraft 1.12 Pre-Release 5, Minecraft 1.12 Pre-Release 6, Minecraft 1.12 Pre-Release 7, Minecraft 1.12, Minecraft 17w31a, Minecraft 1.12.1 Pre-Release 1, Minecraft 1.12.1, Minecraft 1.12.2 Pre-Release 1, Minecraft 1.12.2 Pre-Release 2, Minecraft 1.12.2, Minecraft 17w43a, Minecraft 17w43b, Minecraft 17w45a, Minecraft 17w48a, Minecraft 17w50a, Minecraft 18w01a, Minecraft 18w03b, Minecraft 18w06a, Minecraft 18w09a, Minecraft 18w16a, Minecraft 1.13-pre1, Minecraft 1.13-pre3, Minecraft 1.13-pre10, Minecraft 1.13, Minecraft 18w30b, Minecraft 18w31a, Minecraft 1.13.1
Fix Version/s: Minecraft 18w43a

Type: Bug
Reporter: Hinata Assignee: [Mojang] Georgii Gavrichev
Resolution: Fixed Votes: 49
Labels: cobweb, leaves, light, magma_block, sky, water

Issue Links:
Duplicate
is duplicated by MC-13574 Glowstone lighting issue Resolved
is duplicated by MC-22737 When sky light is blocked it does not... Resolved
is duplicated by MC-56362 sunlight bug with some light emiting ... Resolved
is duplicated by MC-77178 Webs save light. Resolved
is duplicated by MC-110343 Water saving sunlight Resolved
is duplicated by MC-111503 Water blocks, under the right circums... Resolved
is duplicated by MC-114780 lighting error Resolved
is duplicated by MC-120269 Glowing Water 1.12.1 Resolved
is duplicated by MC-124484 Weird auto-lighting bug Resolved
is duplicated by MC-129147 Sea Lanterns absorb natural sky light... Resolved
Relates
relates to MC-102162 Some light-emitting blocks (magma, li... Resolved
relates to MC-117067 Trees/Leaves too bright under big pla... Resolved
relates to MC-13003 Lighting Bug - I shut off light, the ... Resolved
relates to MC-18526 Light with no nearby light sources Resolved
relates to MC-77311 Wrong light level through covered ice. Resolved
relates to MC-119932 Light-emitting solid blocks (lit furn... Resolved
CHK:
Confirmation Status: Confirmed

 Description   
Note

This issue is about sunlight. For the related block light issue, see MC-102162.

The bug

Certain blocks "save" sunlight, emiting it even after the original source has been removed. This creates an annoying glowing spot and is very difficult to clean up given that the blocks are not obviously the source of the glowing (and that it can chain between multiple of them).

Affected blocks (may be incomplete)

  • Water
  • Leaves
  • Cobweb
  • Magma
  • Lit redstone ore
  • Lit furnace
  • Powered redstone lamp
  • Glowstone
  • Sea lantern
  • Jack-o-lantern

Reproduction

  1. Build a sealed room without any lights in it with a single layer between it and the sky.
  2. Place one of the effected blocks on the floor.
  3. Break the ceiling block above that block.
  4. Replace the ceiling block.
  5. Observe that the room remains lit, despite the lack of a light source.

Notes

  • In versions prior to 1.7.2ish, this also affected other blocks (for sure glowstone, lit redstone ore, lit furnaces, and jack 'o lanterns — mostly, blocks that exhibit MC-102162 but also similar blocks that emit full light). In 1.7.2 it was fixed for those blocks. Incidentally, 1.7.2 had a fix that removed an x-ray effect when inside of glowstone; it's possible that those are related. this issue returned for 1.11.2
  • Lava is not effected, despite also being a fluid.
  • Water only finicky about being affected; if it's in a pit it doesn't get affected but if it's above the ground it is.
  • This only happens when the block is in direct sunlight; if it's next to the sunlight but not exposed to the sun it doesn't seem to happen.

Demos

Demonstration from the Minecraft version 1.4.5 : http://youtu.be/8nTd1KbbrLA

EDIT SEPT 19 2015: Demonstration from the Minecraft version 15w38b: https://youtu.be/bPUdssOvU78



 Comments   
Comment by Fabian Röling [ 02/Mar/18 ]

No, it's a bug and the blog author was already notified.

Comment by Somebody62 [ 02/Mar/18 ]

Redstone ore is supposed to do this, according to Minecraft.net here. However, this may be wrong, because I doubt the author would know definitively what the desired behavior should be here.

Comment by [Mod] violine1101 [ 07/Sep/17 ]

carson_he, 1.12.1 has already been marked as affected.

Comment by Carson He [ 07/Sep/17 ]

Confirmed for 1.12.1

Comment by Brasseur Dylan [ 16/Jun/16 ]

Confirmed for 1.10, glowstone not affected. You can see the result with cobweb on this video : https://youtu.be/fZa-kKz-K3E

What i think is that when the ceiling is sealed, all the air blocks's light level underneath are updated but they omit other blocks (for optimisation purpose) so cobweb is not updated except if you place the block just above it (for glass and other stuff it works though)

F3 confirms that the light is skylight, not block light

Comment by user-f2760 (Inactive) [ 21/May/16 ]

Please mark both videos (https://youtu.be/bPUdssOvU78 and http://youtu.be/8nTd1KbbrLA) as either public or hidden, if it's private, we can't watch them.

Comment by Immaterialise [ 17/Feb/16 ]

Confirmed for 1.9-pre1, although glowstone doesn't seem to be affected anymore. It still occurs with water and cobwebs.

Comment by Daniel Burnett [ 30/Nov/15 ]

Confirmed in 15w47c. It interferes with the operation of daylight sensors, which think the "saved" light from glowstone, etc. are daylight and emit a signal where there should be none. It's also difficult to fix once it occurs, because the "sky light" emitting from one block of glowstone will be "saved" as "sky light" in nearby blocks, so they must all be broken before you can replace them or else it'll still think there's skylight around.

Comment by Hinata [ 19/Sep/15 ]

Bug still confirmed in 15w38b. It's been 3 years, maybe it's time to fix it, Mojang?

Comment by kazblox [ 02/Aug/14 ]

EDIT: wait no, I was wrong

Comment by Kyle Cuthbert [ 15/Jul/14 ]

this is still a problem in 1.7.10 and 14w28b

Comment by Sean Wammer [ 05/Jun/14 ]

I can also confirm for 14w21b. Additionally powered redstone blocks act as transparent and exhibit this behavior. It seems that transparent blocks often do not update their light level, thus preserving previous sky light levels.

I've had this same problem with stained glass but am having trouble duplicating it.

Comment by Missingno_26 [ 05/Jun/14 ]

can confirm for 14w21b

Comment by [Mod] Ezekiel (ezfe) [ 29/Jan/14 ]

Is this still a concern in the latest Minecraft version 14w04b? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Comment by Jae Yoon Kim [ 02/Feb/13 ]

Confirmed

Comment by [Mod] CubeTheThird [ 29/Nov/12 ]

Can confirm.

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