March 26, 2026
Nostalgia vs. Playable Proof
Show HN: Fio: 3D World editor/game engine – inspired by Radiant and Hammer
Old‑school map maker vibes are back; fans swoon, skeptics want proof
TLDR: Fio is a small, open‑source 3D level editor/game engine inspired by classics, promising easy “build and play” on modest machines. Commenters are split between glowing nostalgia for Quake‑era mapmaking and a clear challenge to the devs: show a real, playable demo to prove the promise matters.
A tiny open‑source 3D world editor/game engine called Fio just dropped, channeling the old map‑making legends Radiant and Hammer with instant “build it, hit play” energy. It promises real‑time lighting, foggy vibes, water/glass effects, terrain, and Half‑Life 2‑style logic—designed to run on modest laptops. It’s compact, MIT‑licensed, and delightfully retro—right down to a cheeky Lynchian mood.
But the community mood isn’t just warm fuzzies. One camp is deep in nostalgia mode, with voidfunc reliving late‑night clan servers and DIY arenas. The other camp is in full show‑me mode, as tines sums it up with a friendly but pointed: has anything actually been made with this? That single question became the thread’s mini‑boss fight—vibes versus receipts.
Cue the classic jokes: “moody hallway generator,” “will it run on a toaster,” and gentle ribbing about fog and liminal corridors. Brush‑based CSG (think carving worlds from big Lego‑like blocks) sparked cheers from old‑timers who love simple tools, while modern‑engine fans lurked, waiting for a demo reel. Verdict for now: huge throwback energy and a promising toolkit—but the crowd wants a playable map to turn nostalgia into hype.
Key Points
- •Fio is an open-source, brush-based CSG 3D world editor and game engine with a unified renderer.
- •It is inspired by Radiant and Worldcraft/Hammer and aims for a compact, lightweight footprint targeting Snapdragon 8CX and OpenGL 3.3.
- •The custom OpenGL/PyGame engine supports immediate “drop-in and play” workflows similar to the CryEngine Editor.
- •Features include real-time lighting (with stencil shadows in development), volumetric fog, glass and water shaders, terrain generation, and OBJ model support.
- •It uses a JSON level format with a magic number fingerprint, includes an HL2-inspired entity I/O system, is fully modular, and is released under the MIT License with dependencies on PyQt5, numpy, Pillow, PyOpenGL, pygame, and PyGLM.