Furnace Peek

See what's cooking — without opening a single furnace.

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📖 About

Ever walked past a wall of furnaces and wondered which one has your iron in it? Vanilla gives you two dark, empty slits and no answers — the only way to know is to open every single one.

Furnace Peek turns the furnace's front face into a window. The two dark openings show what's actually inside: the item being smelted appears through the top opening, and the fuel appears through the bottom one — rendered right on the block, live, with zero clicks.

It's a purely visual, client-side mod. Nothing about smelting, fuel burn time, recipes, or block behavior changes — the furnace just stops keeping secrets.

🖼️ States

Smelting preview	Fuel preview	Lit & burning
!Smelting item in the top opening	!Fuel item in the bottom opening	!Lit furnace with glow and flame
Top opening shows the input slot	Bottom opening shows the fuel slot	Red glow + flame, arch intact

✨ Features

• 🔍 At-a-glance previews — the smelting item shows in the top opening, the fuel item in the bottom one, using the items' own icons.
• 🔥 Living lit state — while the furnace burns, a warm red glow blends into both openings (pixel-exact, following the opening's natural arch shape), with an animated flame flickering behind the fuel.
• 🧊 Honest unlit state — no burn, no effects: icons show in their natural colors. Empty slot? The opening stays exactly vanilla-dark.
• 📚 Stack-size hints — 1 item shows one icon, 2 show a pair, 3+ show a small pyramid stack.
• 🪨 Still unmistakably a furnace — nothing floats, nothing sticks out. Items sit inside the openings, tucked behind the furnace's own frame; the block silhouette and textures are untouched.
• ⚡ Featherweight — a handful of quads per visible furnace, throttled data refresh. Furnace walls welcome.
• 🔄 Live updates — swap the input, top up fuel, or let the fire die: the face updates within a fraction of a second.

❓ FAQ

Does it work on multiplayer servers? Currently the previews appear in singleplayer (and worlds you host). On dedicated servers the mod stays quietly dormant — furnace contents simply aren't sent to clients by vanilla. Server-side support is on the roadmap.

Smoker and Blast Furnace? Out of scope for this first release — regular furnaces only. The same treatment for their cousins is a natural follow-up.

Does it show the output slot? No, by design. Only the two input-side slots (smelting + fuel) are previewed.

Will it lag with a big furnace array? No. Each visible furnace costs a few quads and a cached, rate-limited data lookup (one refresh per ~200 ms per furnace, only while visible).

Does it change gameplay? Zero. No mechanics, recipes, burn times, or block behavior are touched — it's rendering only.

🧭 Roadmap

• Server-side sync for dedicated-server previews
• Smoker & Blast Furnace support
• Config (toggle glow/flame/stack hints)

📜 License

CC0-1.0 — public domain. Source on GitHub.