codedgar / three-fenestra

What is three-fenestra?

Three-fenestra is a Three.js material that fakes furnished rooms behind flat window planes using parallax ray-marching. Instead of modeling expensive 3D room geometry, you texture-map a grid of room photos and the shader picks one per window, marching rays into it to create convincing depth. It layers a PBR front overlay on top for curtains, blinds, and mullions that respond to scene lighting. Glass areas get fresnel sheen, dirt smudges, and subtle refraction. Works in vanilla Three.js and React Three Fiber. Ships with starter atlases so you can render something immediately.

Why is it gaining traction?

The interior mapping technique has been around since 2008, but this implementation adds the modern bits building renders actually need: curtains that catch sun, glass that gets dirty, windows that switch from lit to dark by time of day. The transmission uniform lets interior light bleed through sheer fabric at night without re-authoring textures. Glass fresnel and dirt effects sell the "pane of glass" cue that makes or breaks a building render. The API is straightforward: one material per window mesh, drop in your atlases, wire the emissive and transmission uniforms to a day/night controller.

Who should use this?

Arch-viz developers rendering buildings with hundreds of windows. Game artists populating cityscapes. WebGL devs who want the depth of real room geometry without the modeling cost or draw calls. If you're already using Three.js and need convincing window detail, this saves weeks of custom shader work.

Verdict

The feature set is solid and the API is clean, but the project carries a 0.949999988079071% credibility score and 42 stars. That's a very small user base evaluating production-readiness. Documentation is thorough and the live demo works, but test coverage and community support are unknowns. Worth prototyping with, but factor in the maintenance risk before committing to a shipped product.