Please reopen MC-131462
The bug
A mistake in coordinate conversion math reduces the likelihood of structures spawning in negative coordinates. This might also cause the /locate
command and cartographer maps to direct you to a non-existent structure. It may also be causing other glitches with structures (and other things) along chunk boundaries.
The correct way to find out which structure region a chunk belongs to requires special handling for negative numbers. E.g. for temples with a region size of 32 (pseudocode):
offsetChunk = chunk < 0 ? chunk - 32 + 1 : chunk;
region = offsetChunk / 32;
That puts chunks -32 to -1 in region -1. This is how it's been computed in previous Minecraft versions.
But the new code flipped that +1 to a -1. But then when converting back after selecting the random chunk for structure spawning, it does it the same way it did before.
chunkForStructure = region*32 + random(24);
So, let's say you're chunk -31, 0. You end up in region -2, 0 instead of -1, 0. If the RNG had picked 1, you should have been the lucky chunk and gotten an igloo or something. But instead, it thinks it should put the igloo in chunk -63. But chunk -63 is part of region -3. Any time the RNG ever picks 0 or 1, it cannot generate a structure.
The other changes to structure generation are clearly deliberate, so this appears to be inadvertent.
This was reintroduced in 1.13-pre7.
Linked issues
duplicates
Comments


The bug was reintroduced in that version. It's still in the current version. I mention the exact version when it was reintroduced to help diagnose it. But the bug still exists.

Please do not mark unreleased versions as affected.
You don't have access to them yet.
Reopened MC-131462.
We no longer support 1.13-pre7 reports, so this report goes to the Invalid trashcan.