Minecraft 26.4 Snapshot 2: Mojang Fixes the Sky and Squashes a Nasty Chunk Generation Crash

Mojang just dropped the second snapshot for 26.4, and while the patch notes read like a graphics engineer's diary at first glance, there's some genuinely useful stuff buried in here for anyone running a server. The headline features are visual: a new sky occluder, smarter fog blending, and a full redesign of the F3 debug screen. But the bug fix list is where things get interesting, including a fix for a crash that's apparently been happening during chunk generation.

You can read Mojang's full rundown on the official snapshot post, but let's break down what's actually worth paying attention to.

The Sky Finally Looks Right

If you've ever noticed the sky doing something weird near the horizon, especially underwater during sunrise or sunset, that's a bug Mojang has apparently known about for over a decade. MC-152504 describes exactly that: the sky overlapping fog underwater in a way that looks broken. Snapshot 2 fixes it as part of a broader overhaul to how terrain fog interacts with the sky and clouds.

When Improved Transparency is enabled, the sky background and any clouds behind terrain now blend into the render distance fog instead of creating a visible seam. Mojang also fixed clouds rendering behind foggy terrain entirely (MC-300250), which was one of those bugs you stop noticing because you've just gotten used to it.

The new celestial occluder is the more visible change here. In the Overworld, the bottom half of the skybox now hides the sun, moon, and stars past a certain angle instead of letting them clip weirdly through terrain or fog. It's a small thing, but anyone who screenshots builds or runs a server with a heavily customized resource pack will probably notice the difference immediately.

"When Improved Transparency is on, sky background and clouds that are behind the terrain are now blended into the terrain render distance fog, making the boundary between the sky and the terrain invisible."

For shader and resource pack developers, this isn't just a cosmetic footnote. The resource pack version bumped to 99.0, and screenquad.vsh got renamed to screentriangle.vsh because, as Mojang put it, it's been rendering a single triangle for a while now anyway. There's also a new blit_clouds.fsh shader and two new shaders specifically for the sky occlusion effect. If your server runs a custom pack or shader setup, budget some time to update it.

F3 Got a Glow Up

The debug overlay redesign is easy to skim past in the patch notes, but it's probably the change regular players will interact with the most. Mojang says it's been reworked to be "easier to read and understand," which, if you've ever squinted at a wall of coordinates and chunk data crammed into tiny text, is overdue.

No word yet on exactly what the new layout looks like structurally since Mojang didn't go into detail in the notes, so the best way to see it is to boot up the snapshot yourself.

The Bug Fixes Server Owners Should Actually Care About

Buried under dozens of tooltip and capitalization corrections (seriously, there are at least 25 of them in this snapshot alone) are a handful of fixes that touch actual gameplay and stability. These are the ones worth flagging for admins and plugin developers:

• MC-312064 fixes a crash that could happen randomly during chunk generation. If your server has been experiencing random crashes on new terrain generation, this is the fix to watch for.
• Swamps were apparently drowning in mushrooms. MC-312046 addresses excessive mushroom generation in that biome, so expect swamp terrain to look a bit less cluttered going forward.
• Donkeys, horses, and mules swimming near shorelines could previously be ridden straight onto land without a partial block to climb onto. MC-312066 closes that exploit-adjacent movement quirk.
• Two separate bugs around instant mining, MC-311758 and MC-311777, are fixed. Both dealt with block breaking particles and sounds continuing to play after the action was already canceled, which was a persistent annoyance in Creative-heavy or build-server environments.
• Modders and datapack authors should note MC-310503 and MC-311780. The first fixed yaw randomization using radians instead of degrees in LivingEntity's constructor, and the second corrected trigonometric functions that weren't properly wrapping angles. Both are the kind of under-the-hood math bugs that can quietly throw off custom mob AI or animation code without anyone realizing why.
• Breaking armor stands or other block-attached entities near a sculk catalyst was draining player experience for no good reason. MC-311924 fixes that.

There's also a batch of input and display fixes that matter more for specific setups than the average player. MC-311451 fixes mouse input not registering on monitors positioned negatively on Wayland, and MC-311424 fixes the Right Shift key getting misread as unbound with certain input methods. Niche, but if that's been breaking your setup, it's finally sorted.

New Data Pack Tools: has_sky_occluder and below_heightmap

Two additions are worth a mention for anyone building custom dimensions or datapacks. A new environment attribute, minecraft:visual/has_sky_occluder, lets you toggle the new sky occlusion effect on or off per dimension. It defaults to true in the Overworld and false in the Nether and End, so custom dimensions will need this set explicitly if the occluder effect is wanted.

There's also a new predicate, below_heightmap, which checks whether a position falls below a specified heightmap value. It's a small addition, but it opens up cleaner structure placement and loot logic for datapack authors who've been working around the absence of this check with messier conditions.

Where This Fits in 26.4

This is only the second snapshot for the 26.4 cycle, and so far the update looks focused heavily on rendering polish rather than new blocks or mobs. That tracks with how Mojang has been pacing updates lately: smaller, more frequent snapshots that chip away at long-standing visual and engine issues rather than one giant content dump. The sky and fog overhaul alone touches bugs that have existed since the early Beta era, so there's clearly some genuine engine cleanup happening under the hood.

For server owners, the practical takeaway is this: if you're running custom resource packs or shaders, you've got homework before updating. Everyone else can mostly just enjoy a slightly less broken-looking sky and a debug screen that doesn't look like it was designed in 2011.

As always, snapshots are for testing, not production servers. Back up your worlds before poking at this one, and keep an eye on the official patch notes for the next snapshot in the cycle.