Java Edition 20w49a

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 "field": " <span style=\"font-size:smaller\"><abbr title=\"decimal\">dec</abbr>: </span>1073741832<br /> <span style=\"font-size:smaller\"><abbr title=\"hexadecimal\">hex</abbr>: </span>40000008",
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}

20w49a is the fourth snapshot for Java Edition 1.17, released on December 2, 2020,^[1] which adds sculk sensors, the dripstone caves biome, and the ability to expand the world height limit.

👁 Image
Sculk sensor

• A new redstone component.
• Detects vibrations, and emits a redstone signal.
• Emits a different strength if connected to a comparator, and the signal strength is based on the vibration's frequency.
• Vibrations can be occluded using wool blocks.
• Can only be obtained via the Creative inventory or commands such as /give.

👁 Image
Dripstone caves

• A new underground biome.
• Made up of primarily dripstone blocks and stone, with large clusters of dripstone blocks hanging from the ceiling, pointed dripstone on the floor and ceiling and many pools of water.
• Does not generate naturally in normal worlds, and can only be generated using buffet worlds with "Dripstone caves" selected as the source biome or using custom world.

Death messages

• Added death messages for being skewered by a falling stalactite:
  • "<player> was skewered by a falling stalactite"
  • "<player> was skewered by a falling stalactite whilst fighting <entity>"

Particles

• New particle types: vibration and dust_color_transition

Tags

• Added the dripstone_replaceable_blocks block tag.
  • Contains the base_stone_overworld block tag and dirt.
  • Used in dripstone generation to determine what dripstone can replace and what pointed dripstone can generate on.
• Added the occludes_vibration_signals block tag.
  • Contains the wool block tag.
  • Blocks in this tag prevent sculk sensors from hearing vibrations if the block is between the sculk sensor and the vibration.
• Added new game_events tag type.
• Added the ignore_vibrations_stepping_carefully game event tag.
  • Contains the step, falling, and shooting projectile events.
  • Game events in this tag are ignored by sculk sensors if the source entity is sneaking.
• Added the vibrations game event tag.
  • Contains every game event.
  • Game events in this tag trigger sculk sensors.

Pointed dripstone

• When in a dimension with ultrawarm set to true, such as the Nether, downwards facing dripstone creates lava particles instead of water particles.

Bundle

• Fullness is now always shown even if advanced tooltips are disabled.

Absorption effect

• The yellow absorption hearts now stay yellow if the player has the Poison or Wither effects, instead of appearing empty.

Freezing

• Frozen hearts now appear in Hardcore mode.
  • However, they appear the same as normal frozen hearts.

Custom dimensions

• Added height and min_y variables to dimension types, allowing for the height limit to be increased in custom world settings.
  • The void now starts 64 blocks below min_y.

Servers

• Removed the max-build-height server setting.

28 issues fixed

From released versions before 1.17

• MC-18880 – The Absorption effect has no texture for poison/wither hearts (appears empty instead).
• MC-46650 – When flying through blocks in spectator mode in , the camera zooms in and out a lot.
• MC-201840 – Optional function tags sometimes don't run even when the tag exists.

From the 1.17 development versions

• MC-203797 – Placing or removing a block over the void causes a DecoderException on servers.
• MC-204314 – Double copper slabs only drop a single slab when mined.
• MC-205043 – Absorption hearts appear broken when taking freezing damage.
• MC-205096 – Hardcore hearts lose all color when player is taking freeze damage.
• MC-205391 – Waxing cut copper does not prevent it from oxidising.
• MC-205629 – Unused sign cache when rendering signs.

From the previous development version

• MC-206553 – Pointed Dripstone creates water particles in the Nether.
• MC-206563 – Pointed dripstone is not connected to the player's hand.
• MC-206578 – Large pillars of stalactites don't fall when the block above is removed.
• MC-206583 – Cauldrons below stalactites at least 2 blocks tall will not fill up.
• MC-206591 – Setting any floating block to a pointed dripstone, causes the replaced block to drop as an item.
• MC-206594 – Large stalactites falling occasionally do not drop all of their pointed dripstone items.
• MC-206606 – Frustum stage of stalactites negates fall damage.
• MC-206613 – Pointed Dripstone duplicates when the block it was attached to is removed.
• MC-206615 – Pointed dripstone's hitbox can extend further than a block, causing nearby stalactites to not be able to fall.
• MC-206642 – Stalactites destroy items they fall on, however stalagmites don't.
• MC-206643 – When a dripstone's hitbox extends into the space of another block, the area that extends into said block cannot be targeted.
• MC-206669 – Inconsistency between dripstone and non-mob entities.
• MC-206682 – Floating dripstone tips are sometimes left behind from large dripstone pillars.
• MC-206689 – Floating pointed dripstone top.
• MC-206691 – Pointed dripstone replaces items with pointed dripstone items.
• MC-206711 – Coding error at net.minecraft.world.entity.Entity.resetPos().
• MC-206790 – Waterlogged dripstone does not update.
• MC-206878 – Pointed dripstone attached to a piston is not removed as the piston extends.
• MC-206961 – Flashing frozen hearts use the poisoned absorption heart texture.