[MC-3667] Light-emitting blocks don't emit light while being moved by a piston, causing flickering Created: 22/Nov/12  Updated: 30/Sep/20  Resolved: 30/Sep/20

Status: Resolved
Project: Minecraft: Java Edition
Component/s: None
Affects Version/s: Minecraft 1.4.5, Snapshot 12w50a, Minecraft 1.4.6, Minecraft 1.4.7, Minecraft 1.5, Minecraft 1.8.1, Minecraft 1.8.3, 1.16.3
Fix Version/s: None

Type: Bug
Reporter: [Mod] markderickson Assignee: Unassigned
Resolution: Duplicate Votes: 4
Labels: None

Attachments: PNG File 2012-11-21_22.46.04.png     PNG File 2015-02-23_23.42.19.png     PNG File 2020-09-24_20.39.29.png    
Issue Links:
Duplicate
duplicates MC-123217 Moving blocks don't inherit behaviors... Open
CHK:
Confirmation Status: Confirmed
Category:
Lighting
Mojang Priority: Low

 Description   

The bug

Upon pushing or pulling a light-emitting block (see below for affected blocks), the light flickers off while it is moving. This can cause performance issues due to excessive lighting updates, as well as just be undesirable in general.

How to reproduce

  1. Construct the contraption shown in this video if testing redstone lamps, or the simple contraption shown in this screenshot if testing Shroomlights or any other blocks
  2. Notice how the redstone lamp flickers every time it is pushed by the piston
  3. Replace the redstone lamp with any other light-emitting block from the list below and notice how this same behaviour is present

Affected blocks

  • Redstone Lamp (lit)
  • Shroomlight
  • Sea Lantern
  • Glowstone
  • Redstone Ore (lit)
  • Magma Block
Original description

Using the setup in the screenshot, the lamp will flicker when the lever is pulled.

Glowstone sometimes exhibits this behavior.



 Comments   
Comment by SunCat [ 30/Sep/20 ]

merged with MC-123217

Comment by [Mod] markderickson [ 16/Sep/20 ]

Thanks!

Comment by SunCat [ 16/Sep/20 ]

The ticket is yours now

Comment by [Mod] markderickson [ 16/Sep/20 ]

Hi! I'd like to request ownership of this report.

Comment by [Mojang] Searge (Michael Stoyke) [ 17/Mar/15 ]

While being moved by pistons, blocks do not emit light.

Comment by Aaron Rhodes [ 24/Feb/15 ]

Happens in 1.8.3 and affects sea lanterns as well as glowstone and redstone lamps. It seems that it does not matter whether the piston pushes or pulls these blocks, the flicker happens either way. I tested this using each set up in the screen shot separately. Hopefully I'm not misunderstanding this issue.

Comment by Galaxy_2Alex [ 30/Oct/14 ]

Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases. If this has been done, we can reopen the issue.

Keep in mind that the "Resolved"-Status on this ticket just means "Answered", and that we are waiting for further information on whether this issue still exists or not. We will reopen it as soon as the requested information has been deliviered.

Comment by Sealbudsman [ 07/Mar/13 ]

also in 1.5.

Comment by Sealbudsman [ 14/Feb/13 ]

In 13w07a, both these blocks flicker, and both when being pushed and pulled.

Comment by FireHunterX [ 03/Dec/12 ]

Yes, it only works when being PULLED by a piston, not pushed.

Comment by Chalmes (Jon) [ 22/Nov/12 ]

I can't get the glowstone lamp to flicker going up. I can see the bottom redstone lamp going on a few ticks before the glowstone lamp turns on, which makes it look a little inconsistent, but the glowstone lamp only flickers for me when coming back down.

Comment by Anon Ymus [ 22/Nov/12 ]

Glowstone flickers both ways, redstone lamps flicker only down.

Comment by Chalmes (Jon) [ 22/Nov/12 ]

Flickers on the way back down again right?

Comment by Anon Ymus [ 22/Nov/12 ]

Confirmed. The glowstone and the lamp don't appear to flicker, but you can see that the light flickers if you set the time to midnight.

Comment by FireHunterX [ 22/Nov/12 ]

Updated.

Comment by Pixelgraph [ 22/Nov/12 ]

Also happens with glowstone.

Comment by FireHunterX [ 22/Nov/12 ]

Delivered.

Don't know what exactly happened, I uploaded it already.

Comment by [Mod] CubeTheThird [ 22/Nov/12 ]

Can you post said screenshot?

Generated at Sun Jan 12 12:01:59 UTC 2025 using Jira 9.12.2#9120002-sha1:301bf498dd45d800842af0b84230f1bb58606c13.