[MC-241216] Terrain blending of old worlds has sharp boundaries for snow on windswept hills

When upgrading old worlds, the terrain blending has sharp snow borders on the windswept hills.

To reproduce:
1.Create a world in 1.17.1 with seed 3. (This seed has windswept hills near spawn.)
2.Load this world in 1.18-pre1 (or other version being tested).
3.Inspect the biome blending at the edges -> No snow on the windswept hills where the biome was blended.

Likely cause: snow turns to rain at a slightly higher elevation in these biomes.

Attachments

S3-1171.zip

Comments

migrated 2021-11-11T21:06:15Z

[media][media][media]

bdm68 2021-11-11T21:08:01Z

Screenshot was taken with seed 3.

tryashtar 2021-11-19T06:50:23Z

Does this still occur when upgrading from 1.17 to pre-4?

bdm68 2021-11-19T21:22:47Z

Affects pre-release 4 and pre-release 5.

Attached is a world save, "S3-1171.zip". This world shows the issue after upgrading near the coordinates -48 29 and -14 346.

bdm68 2021-11-20T05:35:50Z

The world save in this report is referenced in MC-242026 (structures in wrong biome) and MC-241592 (cut off trees) because it replicates issues in both of those reports.

The world save was generated using seed 3 in 1.17.1 and then saving the game without moving from the spawn location.

Moesh 2021-11-22T10:25:22Z

Dupe of MC-241760