Slime Overlay is broken

[ytterx]

Unfortunately, after digging out a whole chunk, I think I found out the Slime Overlay is broken?

Version Minecraft 1.16.5 Java
Seed: 6950385622658651799
The generated map shows chunk 64 -3 to be a Slime Chunk

But, verifying with other tools like https://www.chunkbase.com/apps/slime-finder#6950385622658651799 shows that it is not.

Map generated is using the default orientation:

renders["day"] = {
    "title": "Day",
    "dimension": "overworld",
    "markers": markers,
    "rendermode": "smooth_lighting",
    "world": "minecraft",
}

renders["overlay_slime"] = {
    "title": "Slime Chunk Overlay",
    "dimension": "overworld",
    "overlay": ["day"],
    "rendermode": [ClearBase(), SlimeOverlay()],
    "world": "minecraft",
}
 

[robosphinx]

EDIT: I've just re-read your initial report and it seems I completely misunderstood what you said. I mistakenly thought you said this chunk should be marked and isn't, but you said it should NOT be marked and it is.

[CounterPillow]

It's possible that Minecraft has since changed which chunks are slime chunks. I've not really kept up with it to be honest. I'll see if some constant changed that is causing this.

[CounterPillow]

Still looks accurate to me on a world of mine, I'll have to try with your seed.

[CounterPillow]

With your seed, the overlay seems completely different. I've tried making our java.util.Random emulation match the implementation of opendjk8, to no avail; the slime overlay still doesn't match what that website shows. Are we 100% sure that tool is correct?

[Hraefin]

@CounterPillow / @ytterx Are you using chunkbase for finding the slime chunks? I had a serious problem with that working on my world which was updated from 1.8.2 incrementally over the years to 1.16.2. If I have it load in the level.dat it returns a different seed than the one I used to generate the world and the maps are all wrong. You may want to bounce it across another tool like Amidst or something. That seems to work pretty accurately for me.

[ytterx]

@CounterPillow / @ytterx Are you using chunkbase for finding the slime chunks? I had a serious problem with that working on my world which was updated from 1.8.2 incrementally over the years to 1.16.2. If I have it load in the level.dat it returns a different seed than the one I used to generate the world and the maps are all wrong. You may want to bounce it across another tool like Amidst or something. That seems to work pretty accurately for me.

I'm indeed using chunkbase, but the world is new, generated in 1.16

[Hraefin]

@CounterPillow / @ytterx Are you using chunkbase for finding the slime chunks? I had a serious problem with that working on my world which was updated from 1.8.2 incrementally over the years to 1.16.2. If I have it load in the level.dat it returns a different seed than the one I used to generate the world and the maps are all wrong. You may want to bounce it across another tool like Amidst or something. That seems to work pretty accurately for me.

I'm indeed using chunkbase, but the world is new, generated in 1.16

Did you try loading your world file into chunkbase and see what seedc it says? Double check against the actual seed. You might want to try amidst for slime chunk checking. It works perfectly as far as I know and if it differs from overviewer in the same way, that would be confirmation of a bug.