Slimes are not spawning in my slime farm. I dug out a 16x16 area that I saw in the AMIDST. The dimensions are correct. light level is 10-12. I think there's a ravine type of thing just beside my farm. Is that a problem? The hole on wall is the entrance to ravine. I can hear a few mobs from here and the ravine is lit up.
There are a number of issues to be aware of when building a slime farm. It is not clear from your description if you took all of them into account, so I'll list them all:
- You know slimes only spawn in certain chunks. So, no worries there, but for future readers, just making that point clear. Amidst is one excellent tool for finding spawn chunks.
- Slimes only spawn below level 40. It isn't clear if your spawning pad is below level 40 or not.
- Slimes spawn more rarely than other mobs, so you need to have a lot more slime spawnable areas than normal mob spawning areas. The typical way to accomplish this, is to light up all surrounding caves, and the entire overworld in a 128 block radius around your spawning pad.
When I built a slime farm several months ago these were some of the things I learned:
Slimes are shy - they won't spawn if other mobs are nearby. Assuming your area is in the correct zone (inside a Slime spawn chunk and within ~40 blocks from bedrock), you also need to check the ravine nearby and light it with torches to keep other mobs from spawning nearby and stopping the Slimes from spawning.
You also have to stay close to the chunk (maybe even within it) for long periods of time to ensure the slimes will span because they won't spawn if you leave the area (I built a fishing platform and alchemy/enchanting lab above my farm to keep the chunk active and stay busy with interesting tasks).
There are these areas called slime chunks (source):
Slimes spawn throughout the world (except mushroom islands) below layer 40 regardless of light level, but only in certain chunks, 1 in 10 of all chunks. These "slime chunks" are determined pseudo-randomly by combining their chunk coordinates with the seed of the world:
Random rnd = new Random(seed + (long) (xPosition * xPosition * 0x4c1906) + (long) (xPosition * 0x5ac0db) + (long) (zPosition * zPosition) * 0x4307a7L + (long) (zPosition * 0x5f24f) ^ 0x3ad8025f); return rnd.nextInt(10) == 0; That is, using the chunk coordinates to help generate a seed, a random number between 0 and 9 will be generated, and if that number is 0, the chunk will be able to spawn slimes. To convert world coordinates to chunk coordinates, divide by 16 and round down
If you want to do it in swamp (source):
In swamps, slimes may spawn at night between the heights of 50 and 70 provided the light level is 7 or less. They spawn most often on a full moon, and never on a new moon.
More precisely, the game checks if the light level is equal to or less than a random integer (from 0 to 7), then if the fraction of the moon which is bright is greater than a random number (from 0 to 1). If these conditions are met and the altitude is acceptable, there is a 50% chance of spawning a slime.
And my few tips to end it of:
Make a mine at the maximum height where can spawn Bedrock (the floor is height 6) and make it flat. Mine resources and get slimes!
Enjoy your slimeballs!
Quotes from minecraft wiki.