I have a generic mob grinder near my main base which is build on land and far from sea.
That was my very first "farm" ever, there are things I would correct now ...
I made another one using flying machines in Skyblock (1.12) world recently and mobs were just litterally raining.
The first one has a very slow spawnrate, and I always considered that this wa due to it build underground in the continent, so there are probably unexplored caves here and there.
I decided to build a new grinder the way I would build it with some more experience, and I have always heard that the middle of the ocean was a good place for spawning due to the absence of other spawning places. I placed it in the middle of an ocean, altitude ~230 and "AFK floor" approximately 24~28 levels below. In a day of existence, this grinder spawned something like 1 skeletons and 3 zombies. That's is even slower than anything I would have imagined.
In the meantime, my "continental" mob grinder, still being very, feels infinitely faster ...
I just done a visit of the the surroundings with elytras, the closest thing I found is my own guardian farm at approx. 179 blocks away (closest blocks), but yet, under altitude 63 . From what I head, 128 blocks away from "anywhere" is enough.
Any advice/idea on why this farm in the sky and in the middle of the ocean is not spawning anything ?
This sounds like an instance of a known bug "Minecraft 1.13 Mob spawn rate" [ https://bugs.mojang.com/browse/MC-134969 ] which is claimed as fixed by 1.13.2, although reports to the contrary are still being made…
" Mop Spawn rates are still very low in 1.13.2 " [ https://bugs.mojang.com/browse/MC-139904 which is marked BOTH "resolved" & "awaiting response" and still recieving reports as of 06Dec18 ] may also be relevant.
Rollback Post to RevisionRollBack
"Why does everything have to be so stoopid?" Harvey Pekar (from American Splendor)
WARNING: I have an extemely "grindy" playstyle; YMMV — if this doesn't seem fun to you, mine what you can from it & bin the rest.
Any advice/idea on why this farm in the sky and in the middle of the ocean is not spawning anything ?
It is NOT true (nor has it ever been) that mobs will only spawn up to 128 blocks away. That's a misunderstanding of the mechanics going on. What it really means is that mobs will not exist in the world further away than 128 blocks from the nearest player. In 1.12, we could clearly see that mobs were spawning further away than 128 blocks...they would spawn, which triggers an AI event (if I recall, this is part of the mob initialization process), and in the course of resolving this action the mob gets despawned. This doesn't happen in 1.13, but the game is still picking spots in this invalid zone to check for spawnability. The "cod AI" fix didn't mess with how the game spawns mobs, it only messed with where they could be successfully placed (another example of this style of fix is the maximum world border).
Thus, you probably have a lot more water within spawning range than you realize and the game is simply wasting a lot of spawn cycles rejecting these spots.
Regarding players, that, I understand, I don't think that there were players in the area, even considering much more than 128 blocks.
The rest of your reply is interesting but confusing.
- This would confirm what I once thought that the AI could waste spawn cycles selecting spawnable blocks then discarding them for some reason. Right?
- Then it also invalidates all the wide-spread advice that say things like "make all caves withing 128 blocks unspawnable"? In the sense that it's not necessarily enough.
- And then it would also be better to make such a build on continent than ocean ? Because all water blocks are potentially spawnable while on continent, filled blocks are not spawnable, only caves and surface are spawnable, which makes manyless spawnable blocks?
Other players can mess up your spawn rates wherever they are (in the same dimension) mobs that have spawned near them can fill up your shared mob cap.
Most of the wasted spawn cycles would be selecting random blocks that turn out to not be spawnable.
As I understood things mobs spawned in cubes 256 blocks on a side with the X and Z values centered on a player and the Y value being 0-255 and then mobs that were outside spheres with a 256 block diameter (128 block radius) centered on any player despawned.
According to DuhDerp they no longer spawn outside the spheres.
You absolutely want to make everything within 128 blocks (preferably within 128 blocks of all players) but outside your mob farm unspawnable, unspawnable blocks may waste spawn cycles, which only slows down spawning, but spawnable blocks spawn mobs that fill up the mob cap and stop more mobs from spawning.
If you aren't going to build way up in the air then yes, land would probably be better than sea, caves are easier to mob proof than oceans.
Now, about the wasted spawn cycles, apparently Minecraft only checks up to the highest solid block in a chunk (before 1.13 rounded up to an even 16 blocks) so, for the absolute maximum spawn rates (which probably aren't worth aiming for on a server) you'd want to build your mob farm as low as possible, like WAY down on the bedrock and keep the farm itself as flat as possible, and remove all blocks above it as well as spawn proofing everything within 128 blocks of your position.
Now, you obviously have some other problem that needs to be addressed before you put any effort into optimization.
At around 130 blocks above the surface you shouldn't be causing drowned to spawn in the ocean so it seems like its either a bug, as suggested earlier in the thread, some server setting, something wrong with your design or mobs around other players filling up the mob cap.
How big a server is it?
Can you see any difference in spawn rates when there are fewer players on?
--
Can you tell what biome you're in?
It would be maximally unlucky to have happened to build it right above a mushroom island.
I'm aware of the mob caps/server things, but that wouldn't explain why at the same moment my ocean-sky grinder spawns littarelly nothing (5 mobs/day), while my continental underground grinder is working slowly but "infinitely" faster.
Minecraft only checks up to the highest solid block
If it checks only the highest, how do mobs spawn in caves ?
256 block diameter (128 block radius)
Then, since I'm ~130 above sea level ... I should be fine?
Can you tell what biome you're in?
It would be maximally unlucky to have happened to build it right above a mushroom island.
I would not have built on top of mushroom island but I didn't check the biome. The biome is "deep_cold_ocean" ... would that explain something?
I didn't chec
I'm aware of the mob caps/server things, but that wouldn't explain why at the same moment my ocean-sky grinder spawns littarelly nothing (5 mobs/day), while my continental underground grinder is working slowly but "infinitely" faster.
No it wouldn't.
The only things I can think of are what I mentioned, being in a mushroom island biome, some server settings or plugin or something wrong with the design of the spawner.
I would not have built on top of mushroom island but I didn't check the biome. The biome is "deep_cold_ocean" ... would that explain something?
I didn't chec
I wouldn't think so, I'm pretty sure animals won't spawn in ocean biomes but as far as I know Mushroom Islands (and Ocean Monuments) are the only place that normal hostiles don't spawn.
What I tried is to build a grinder in a player built town. Expecting the most player built areas around it would be unspawnable and players being around would trigger spawn. I made the small design relying on water which is more compact and much faster to build than those with flying machines... and so far it's the best performing of my 3 generic mob grinders. (Still nowhere near the performance of my Skyblock grinder.)
(on a multiplayer 1.13 semi-vanilla server)
I have a generic mob grinder near my main base which is build on land and far from sea.
That was my very first "farm" ever, there are things I would correct now ...
I made another one using flying machines in Skyblock (1.12) world recently and mobs were just litterally raining.
The first one has a very slow spawnrate, and I always considered that this wa due to it build underground in the continent, so there are probably unexplored caves here and there.
I decided to build a new grinder the way I would build it with some more experience, and I have always heard that the middle of the ocean was a good place for spawning due to the absence of other spawning places. I placed it in the middle of an ocean, altitude ~230 and "AFK floor" approximately 24~28 levels below. In a day of existence, this grinder spawned something like 1 skeletons and 3 zombies. That's is even slower than anything I would have imagined.
In the meantime, my "continental" mob grinder, still being very, feels infinitely faster ...
I just done a visit of the the surroundings with elytras, the closest thing I found is my own guardian farm at approx. 179 blocks away (closest blocks), but yet, under altitude 63 . From what I head, 128 blocks away from "anywhere" is enough.
Any advice/idea on why this farm in the sky and in the middle of the ocean is not spawning anything ?
This sounds like an instance of a known bug "Minecraft 1.13 Mob spawn rate" [ https://bugs.mojang.com/browse/MC-134969 ] which is claimed as fixed by 1.13.2, although reports to the contrary are still being made…
" Mop Spawn rates are still very low in 1.13.2 " [ https://bugs.mojang.com/browse/MC-139904 which is marked BOTH "resolved" & "awaiting response" and still recieving reports as of 06Dec18 ] may also be relevant.
It also say unconfirmed ... maybe it's "resolved" because it doesn't require treatment any more?
It is NOT true (nor has it ever been) that mobs will only spawn up to 128 blocks away. That's a misunderstanding of the mechanics going on. What it really means is that mobs will not exist in the world further away than 128 blocks from the nearest player. In 1.12, we could clearly see that mobs were spawning further away than 128 blocks...they would spawn, which triggers an AI event (if I recall, this is part of the mob initialization process), and in the course of resolving this action the mob gets despawned. This doesn't happen in 1.13, but the game is still picking spots in this invalid zone to check for spawnability. The "cod AI" fix didn't mess with how the game spawns mobs, it only messed with where they could be successfully placed (another example of this style of fix is the maximum world border).
Thus, you probably have a lot more water within spawning range than you realize and the game is simply wasting a lot of spawn cycles rejecting these spots.
Regarding players, that, I understand, I don't think that there were players in the area, even considering much more than 128 blocks.
The rest of your reply is interesting but confusing.
- This would confirm what I once thought that the AI could waste spawn cycles selecting spawnable blocks then discarding them for some reason. Right?
- Then it also invalidates all the wide-spread advice that say things like "make all caves withing 128 blocks unspawnable"? In the sense that it's not necessarily enough.
- And then it would also be better to make such a build on continent than ocean ? Because all water blocks are potentially spawnable while on continent, filled blocks are not spawnable, only caves and surface are spawnable, which makes manyless spawnable blocks?
Other players can mess up your spawn rates wherever they are (in the same dimension) mobs that have spawned near them can fill up your shared mob cap.
Most of the wasted spawn cycles would be selecting random blocks that turn out to not be spawnable.
As I understood things mobs spawned in cubes 256 blocks on a side with the X and Z values centered on a player and the Y value being 0-255 and then mobs that were outside spheres with a 256 block diameter (128 block radius) centered on any player despawned.
According to DuhDerp they no longer spawn outside the spheres.
You absolutely want to make everything within 128 blocks (preferably within 128 blocks of all players) but outside your mob farm unspawnable, unspawnable blocks may waste spawn cycles, which only slows down spawning, but spawnable blocks spawn mobs that fill up the mob cap and stop more mobs from spawning.
If you aren't going to build way up in the air then yes, land would probably be better than sea, caves are easier to mob proof than oceans.
Just testing.
Now, about the wasted spawn cycles, apparently Minecraft only checks up to the highest solid block in a chunk (before 1.13 rounded up to an even 16 blocks) so, for the absolute maximum spawn rates (which probably aren't worth aiming for on a server) you'd want to build your mob farm as low as possible, like WAY down on the bedrock and keep the farm itself as flat as possible, and remove all blocks above it as well as spawn proofing everything within 128 blocks of your position.
Now, you obviously have some other problem that needs to be addressed before you put any effort into optimization.
At around 130 blocks above the surface you shouldn't be causing drowned to spawn in the ocean so it seems like its either a bug, as suggested earlier in the thread, some server setting, something wrong with your design or mobs around other players filling up the mob cap.
How big a server is it?
Can you see any difference in spawn rates when there are fewer players on?
--
Can you tell what biome you're in?
It would be maximally unlucky to have happened to build it right above a mushroom island.
Just testing.
I'm aware of the mob caps/server things, but that wouldn't explain why at the same moment my ocean-sky grinder spawns littarelly nothing (5 mobs/day), while my continental underground grinder is working slowly but "infinitely" faster.
If it checks only the highest, how do mobs spawn in caves ?
Then, since I'm ~130 above sea level ... I should be fine?
I would not have built on top of mushroom island but I didn't check the biome. The biome is "deep_cold_ocean" ... would that explain something?
I didn't chec
No it wouldn't.
The only things I can think of are what I mentioned, being in a mushroom island biome, some server settings or plugin or something wrong with the design of the spawner.
"Up to"!
So it checks the highest solid blocks in the chunk and everything lower than that but nothing higher.
I would have thought so.
I wouldn't think so, I'm pretty sure animals won't spawn in ocean biomes but as far as I know Mushroom Islands (and Ocean Monuments) are the only place that normal hostiles don't spawn.
Just testing.
What I tried is to build a grinder in a player built town. Expecting the most player built areas around it would be unspawnable and players being around would trigger spawn. I made the small design relying on water which is more compact and much faster to build than those with flying machines... and so far it's the best performing of my 3 generic mob grinders. (Still nowhere near the performance of my Skyblock grinder.)