A truly fabulous snapshot enters the arena! This snapshot brings fundamental changes to our rendering pipeline with the introduction of the brand new tech that is OpenGL Core 3.2. On top of that, we're finally introducing the Lush Caves biome. However, as with the Dripstone Caves, this is only available through creating a custom world.
There's an important note about this snapshot for those of you with older computers: With the introduction of OpenGL Core 3.2 there is a chance Minecraft Java will no longer run on computers that do not meet the minimum system requirements. Computers that meet the minimum system requirements should not be affected.
New Features in 21w10a
Added Lush Caves underground biome!
Added Cracked Deepslate Bricks and Cracked Deepslate Tiles
There is now an Infested variant of Deepslate found in the underground
While they will not generate in the world by default, Deepslate versions of copper, emerald and coal ores have been added for use by creators of maps and data packs
Lush caves biome
The Lush Caves underground biome now exists for use in single-biome worlds. It does not yet generate in other world types.
Moss covers the floors and ceilings
Spore Blossoms grow from the ceiling and drip particles
Contains clay pools with dripleaf plants grow out of them
Contains azalea bushes and flowering azalea bushes
The azalea tree loves to have its roots in lush caves, so if you find an azalea tree (either overground or in a cave) you know there is a lush cave beneath you
Cave vines with glow berries grow from the ceiling and light up the caves
Changes in 21w10a
Cobbled Deepslate can now be smelted into Deepslate.
Deepslate can now be placed along any axis
Lightning rods can now be waterlogged
Fossils in the deepest part of the underground generate with deepslate diamond ore instead of coal ore
Some ore textures have been updated
Ore texture changes in snapshot 21w10a. Click here for a link to the full resolution image.
New textures for emerald, coal, and copper in Deepslate. Click here for a link to the full resolution image.
Ore distribution
Overworld ore generation has been tweaked.
More emeralds in mountains
More lapis
Less copper, gold, and redstone
Smaller diamond blobs, but slightly more frequent. Less diamond ore overall though
Less iron, and it generates lower down
Reduced air exposure for coal
Ore distribution in snapshot 21w10a. Click here for a link to the full resolution image.
Technical Changes in 21w10a
The game now runs using OpenGL 3.2 core profile
The maximum size that slimes can be summoned with is now 128
The give command can only give up to 100 stacks of items at a time (e.g. 6400 stone or 100 iron swords)
OpenGL
Rendering is now using OpenGL 3.2 core profile. All fixed function rendering has been replaced with shader based rendering.
Shaders
Shaders are now included for all supported render states. Any shader except for the blit shader can also be replaced in resource packs. For now replacing these shaders is not officially supported and the way it works may change in the future.
The current rendering engine uses a system similar to the post processing shader pipeline. There are some differences between both system that cater to the slightly different requirements.
Bugs fixed in 21w10a
MC-29318 Client misses inventory updates while player is manipulating items causes invisible items
MC-84121 Shape of glow effect is based on mob's base layer
MC-87019 Only visible slots are updated clientside when you are inside an inventory
MC-154094 Lectern running /clear turns items into ghost items
MC-175964 Setblock command run by book in lectern to clear inventory run in command block causes ghost items
MC-201316 The /give command can create so many items that the game will freeze
MC-207818 Placing a sign from the offhand closes the sign UI immediately
MC-208301 /clear does not properly affect the item on the mouse pointer after crafting it
MC-210408 /spawnpoint allows players to set their spawnpoint to out-of-bounds coordinates, which crashes the game when trying to respawn