Ars Sky Shader Fix

Ever put down an Ars Nouveau Sky Block, loaded up your favourite Iris shaders, and… stared at a big black cube? Yeah. This tiny addon fixes exactly that.

Ars Nouveau draws the Sky Block with its own little custom shader. Iris politely ignores custom shaders when a shaderpack is running, so the block just turns pitch black. This mod steps in and draws the block through the shaderpack's own sky instead — so it actually shows the sky again, shaders and all.

What you get

With a supported shaderpack active, the Sky Block becomes a proper window to the sky:

• Real sky colour straight from your shaderpack (not a fake approximation).
• Clouds, sun, moon and stars shining through the open sides — it genuinely looks like a hole in the world, with the pack's own day/night cycle.
• Correct depth — the open faces occlude properly (no X-ray) and the solid top stays buildable and walkable.
• No shadow cast by the Sky Block itself.

No shaderpack? Nothing changes — you get the normal vanilla effect.

How it works

Set the config to SHADER and the mod injects the sky into your shaderpack at runtime, in memory — it never touches the files in your shaderpacks folder. It detects the pack automatically and applies the right patch for that family. Nothing to install into the pack, nothing to reload by hand.

Supported shaderpacks (tested)

Plenty of other packs that draw their sky the "normal" way happen to work out of the box in SHADER mode too (sky + correct depth) even without a dedicated patch — Sunflawer is one example. Give your pack a try; if the sky and occlusion look right, you're good.

Packs that aren't compatible (pathtracers like SEUS PTGI and Kappa, or packs that build their sky in an unusual way) will show one of two tells in SHADER mode:

• an X-ray effect — the open faces don't hide what's behind them, or
• a plain green block — that green is the mod's internal sky marker, and that pack just doesn't know how to paint over it.

If you see either, that pack needs a dedicated patch (or can't be supported). Support is per-family because every pack builds its sky differently — the list above grows over time.

Config (renderMode)

• SHADER — the real deal, described above. Runtime-injected pack sky (sun/moon/stars/clouds), correct depth, buildable top, no shadow. Use this if your pack is on the list.
• HYBRID — not a real fallback — think of it as a "this is roughly how it could look" preview, not a mode to actually play in. It fakes the window per block and is brutally expensive: you can go from a capped 60 FPS to single digits just running past a wall of Sky Blocks — yes, even on a high-end GPU. It's a proof of concept, not a daily-use option.
• SKYBASIC — a solid block painted by the pack's own sky shader: real sky colour and sun, cleanly hides whatever's behind it. Cheap and stable, but no clouds.
• SOLID — a flat, sky-tinted cube. Cheapest, always works, no frills.

Rule of thumb: supported (or compatible) pack → SHADER. Want something cheap and clean on an unsupported pack → SKYBASIC or SOLID. HYBRID is only there to show what a full window looks like — don't rely on it.

Finding placed Sky Blocks

Because the open faces blend perfectly into the sky, a placed Sky Block can be almost impossible to spot. So the top face is given a solid colour (soft lavender by default) — from above it reads as a normal block. You can recolour it or turn it off:

• topMarker — true/false (default true).
• topColorR / topColorG / topColorB — 0–255 each. Presets in the config comments (white, magenta, red, cyan, amber, …).

Requirements

• Minecraft 1.21.1 (NeoForge)
• Ars Nouveau
• Iris (the whole point — without it the vanilla effect is used as-is)

Two things that are not bugs (please don't report them 🙏)

Some stuff simply lives outside what a mod can control, so heads up:

1. A block sitting on top of the Sky Block can hide the sun/moon. If a pack draws the sun/moon as procedural sky elements, they show through fine. If it uses the vanilla textured sun/moon (e.g. SEUS Renewed's moon and stars), that's a separate object a block on top genuinely blocks — nothing the mod can do. This is noted per pack in the table above.

2. Floating builds cast a shadow on the ground below. If you make a floating platform of Sky Blocks and build on it, the stuff on top casts a normal shadow downward — exactly like any floating build would. The Sky Block itself casts no shadow, but real blocks placed on it do, and that's just how shadows work. Not fixable from the mod side.

Everything else? Fair game — bug away.