Slimes spawn less frequently if there are any blocks above their spawning spaces
The bug
Since 1.14, slimes in spawn chunks (and from spawners?) spawn less frequently if there are any blocks (even glass) above their spawning spaces.
To reproduce
- Find a slime chunk
- Clear it completely, down to level 4 (for example) and make sure the spawning platform is adequately lit
- Count how many slimes spawn in a certain time frame
- Fill layers 20 to 64 with blocks (for example, you can also choose another amount of layers)
- Count again how many slimes spawn in the same amount of times
→
Significantly less slimes spawned
Original description
In my survival, I built a slime farm and I checked for slime chunks, and yet, slimes still aren't spawning. So I went to creative because I have cheats on and tried to spawn one with an egg but these slimes will just pop into existence and then pop out. I tried this in my farm and on the surface for about 10 minutes to no avail.
Linked Issues
is duplicated by9
MC-149039Slime chunksDuplicateMC-1538721.14.2 Slime chunk spwaningDuplicateMC-156187Slime don't spawn in slime chunks - 1.14.3DuplicateMC-158493Slimes not spawningDuplicateMC-159087Slimes stopped spawning in Amplified WorldDuplicateMC-161752Slimes aren't spawning? DuplicateMC-165162Glass blocks and many other transparent / non solid blocks affect mob spawningDuplicateMC-179691Slime chunks do not generate slimes more than a onceDuplicateMC-192856Slimes not spawning in slime chunksDuplicateAttachments1
Created Issue:
Slimes not spawing in slime chunks nor in slime spawner
In my survival, I built a slime farm and I checked for slime chunks, and yet, slimes still aren't spawning. So I went to creative because I have cheats on and tried to spawn one with an egg but these slimes will just pop into existence and then pop out. I tried this in my farm and on the surface for about 10 minutes to no avail.
![[Mod] Asteraoth](../../../data/avatars/users/92886.png){kind=small}
is duplicated by
relates to
is duplicated by
![[Helper] Johnibur](../../../data/avatars/users/28381.png){kind=small}
Please provide a world download with this issue. Without any further information, we are unable to reproduce or diagnose this issue.
In my survival, I built a slime farm and I checked for slime chunks, and yet, slimes still aren't spawning. So I went to creative because I have cheats on and tried to spawn one with an egg but these slimes will just pop into existence and then pop out. I tried this in my farm and on the surface for about 10 minutes to no avail.
![[Bot] Arisa](../../../data/assets/gravatar/mustek2.png){kind=small}
![[Mod] violine1101](../../../data/avatars/users/92858.png){kind=small}
is duplicated by
In my survival, I built a slime farm and I checked for slime chunks, and yet, slimes still aren't spawning. So I went to creative because I have cheats on and tried to spawn one with an egg but these slimes will just pop into existence and then pop out. I tried this in my farm and on the surface for about 10 minutes to no avail.
is duplicated by
relates to
The bug
Since 1.14, slimes in spawn chunks (and from spawners?) spawn less frequently if there are any blocks (even glass) above their spawning spaces.
To reproduce
- Find a slime chunk
- Clear it completely, down to level 4 (for example) and make sure the spawning platform is adequately lit
- Count how many slimes spawn in a certain time frame
- Fill layers 20 to 64 with blocks (for example, you can also choose another amount of layers)
- Count again how many slimes spawn in the same amount of times
→Original description
In my survival, I built a slime farm and I checked for slime chunks, and yet, slimes still aren't spawning. So I went to creative because I have cheats on and tried to spawn one with an egg but these slimes will just pop into existence and then pop out. I tried this in my farm and on the surface for about 10 minutes to no avail.
Slimesnot spawing in slime chunks nor in slime spawnerSlimes spawn less frequently if there are any blocks above their spawning spaces
is duplicated by
is duplicated by
![[Mod] SPGoding](../../../data/avatars/users/44622.png){kind=small}
is duplicated by
![[Bot] Arisa](../../../data/avatars/users/43007.png){kind=small}
![[Mojang] Adrian Östergård](../../../data/assets/gravatar/nighter.jpeg){kind=small}
![[Mod] ampolive](../../../data/avatars/users/18949.svg){kind=small}
is duplicated by
Slime chunks will be tracked at MC-153326.
Thank you for your report!
We're actually already tracking this issue in MC-153326, so I resolved and linked this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.
Thank you for your report!
We're actually already tracking this issue in MC-153326, so I resolved and linked this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.
Does MC-153326 describe your issue?
There is a separate issue with slime spawning: MC-153326. Perhaps that is relevant for you.
Thank you for your report!
We're actually already tracking this issue in MC-153326, so I resolved and linked this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – 📖 Game Wiki
Thank you for your report!
We're actually already tracking this issue in MC-153326, so I resolved and linked this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – ✍️ Feedback and Suggestions – 📖 Game Wiki
Does MC-153326 explain your issue?
No the mob cap appears to be fine. It might be related to MC-153326 but I'm not seeing this on the 1.15.2 build. I raised the issue because I've built these 100's of times now without any issues and the first time I did it in a snapshot for 1.16 it's not spawning anything. Like I said I used the exact same seed and mined out exactly the same area with the same lighting and in 1.15.2 I see slimes spawning and in 20w21a I've not seen a single one.
If people are seeing this working then I'm happy to close the issue, I raised it to find that out really.
Does MC-153326 describe your issue?
Does MC-153326 describe your issue?
Thank you for your report!
We're tracking this issue in MC-153326, so this ticket is being resolved and linked as a duplicate.
That ticket has already been resolved as working as intended, which means this is not considered a bug and won't be fixed. Please do not leave a comment on the linked ticket.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki
![[Mod] Jiingy](../../../data/avatars/users/91802.png){kind=small}
This is working as intended per the resolution of MC-153326 (see MC-165162 which was resolved as a dupe, but more closely fits the description of this issue). The spawning algorithm works in that it sorts from the top most block of the world down to the bottom most block, regardless of it being opaque or not
Cannot reproduce, slimes do spawn underground just fine for me
Since the 1.14.3 version was marked as duplicate add it to the affected versions
Slimes don't spawn in spawn chunks on my 1.14.4 server but they do spawn in swamps
Cannot reproduce. Please provide world seed and slime chunks coordinates if you have this issue.
Slimes dosen't spawn on my singleplayer word in slime chunks. Tried in multiple chunks, multiple times, for a week now. Still not a single slime spawned. The world was generated in the early snapshots of Minecraft Java edition 1.14
https://bit.ly/2GJrp5I Here is a world download of my survival world, where i came accross and tested the issue. The world was generated in the early snapshots of Minecraft Java edition 1.14. Now playing in 1.14.4
Slime spawn rates in slime chunks are negligible compared to same conditions in 1.12 and 1.13. Unless the whole chunk is mined out the rate appears to be negligible.
Chunk 0 0 -5, has had one spawn of the test world I attached, this is negligible to the rate prior to 1.14. Chunk 3 0 -2, have been experiment with. Currently with glass, but the rate is severely cut from having no block above the platform.
Slime test.zip
I have checked the attached world and it seems like slimes are indeed spawning, albeit at a much slower rate than previously.
What could be the reason for the "much slower rate"?
As of 1.14, all blocks other than air raise the max height of any particular (x, z) coordinate. Every slime spawn attempt at a particular (x, z) coordinate is distributed from bedrock to the corresponding max height. In previous versions, blocks like water and glass didn't raise the max height, so you could simply bomb a little hole in the bottom of the ocean and cover the top with glass to make a slime farm. Now in 1.14, you need to remove every block above the farm to get the same rates as previously.
It also helps significantly to dig out an area about 20 blocks out from your slime farm (as well as all blocks above this larger area), as this drastically increases the chance that spawn attempts will start in adjacent chunks and make their way to your slime chunk due to how pack spawning works.
In my testing I applied a glass roof and the rate appeared to have at least halved. Efficiency of a farm isn't the problem. I usually create a farm close to my base, passively generating slime and letting their own pathing algorithm remove them from the platforms. Now, to get any rates similar to 1.12 and 1.13, I have to create a hole, which I don't want near my base. Since its not near my base, i have to afk at it. As a casual player who wants to build a design using slime, but i am required to build a farm that would take 6 hrs compared to an hour, I am not inspired to play.
Efficiency isn't the problem when the spawning algorithm has changed, making spawn rates negligible unless you are trying to make a efficient design.
Alright, I have edited this ticket so that it actually includes that blocks above the spawning platform decrease the spawning frequency immensely, and I was able to confirm that.
While killing all other mobs that were spawning, in the slime chunk with no roof, 18707 slimes spawned, while in the one with a bunch of blocks above it, only 1369 spawned.
I repeated the experiment with glass instead of sandstone above the chunk with a roof, and here the numbers were similar (18082 without roof, and 1307 with glass above).
This is WAI. Since light went to its own thread, spawn algorithm uses a different heightmap to determine topmost spawnable block as the top block that is not air, rather than top block that is not transparent. There is no other heightmap that the spawning algorithm could currently use. That change was deliberate and intended. Just remove all the blocks above your farms and not worry about it.
Yes. The question is only, is it intentional that slimes have become way more rare than previously or is it an unintentional side effect of those changes? Of course the new behaviour can be explained with the new lighting engine from 1.14, but that doesn't mean that slimes underground were supposed to become rarer.
Oh interesting, I thought something was goofy-