three-live: Google's AI-first 3D engine — one Three.js codebase, native on Android, iOS and Web

Write one Three.js codebase: it renders through Filament on Android, RealityKit on iOS/visionOS, and WebGL2/WebXR on the Web — not a WebView wrapper, but native rendering on each platform. three-live, open-sourced by Google (Apache-2.0, TypeScript, 200 stars as of November 8, 2026, created October 2), calls itself an “AI-first Native 3D, CAD & spatial computing runtime and JIT compiler”: Three.js scene code — written by AI or a human — is JIT-compiled and dispatched to native render pipelines on all three targets.

Core features

• One codebase, three native targets: Filament on Android, RealityKit on iOS/visionOS, WebGL2/WebXR on Web — no WebView shell.
• 36 built-in plugins: CAD modeling, skeletal animation, gesture interaction, Gaussian Splatting, spatial measurement and more.
• 100k+ open 3D models: code-defined, so resizing is a parameter change.
• AI-first: designed for the “AI generates Three.js scene code, rendered natively” pipeline — a natural fit for agent workflows.

Typical use cases

• Cross-platform 3D apps: product visualization, digital twins and spatial-computing demos delivered from one codebase.
• AI-generated 3D scenes: agent-written Three.js code running on real devices.
• CAD and spatial measurement: built-in plugins cover industrial scenarios.

Quick start

Follow the docs at google.github.io/three-live; the repo carries examples for all three targets. JIT compilation means scene changes hot-reload into the running native app — a much shorter loop than the traditional edit-rebuild-redeploy cycle. The project also positions itself as the runtime for AI-generated 3D scenes: an agent or human writes Three.js code, and three-live compiles it to each platform’s native pipeline — generated code never needs to know whether the target renders through Filament or RealityKit.

Relation to existing options

It does not replace Three.js itself — the Web path still runs Three.js on WebGL2/WebXR. The increment is on mobile native: Three.js on Android and iOS previously meant WebView or hand-built bridges, and three-live fills the “native performance” tier with Filament and RealityKit. The 36 plugins lean toward industrial and spatial-computing scenes — CAD, Gaussian Splatting and spatial measurement — rather than web-page decoration.

Summary

three-live fits teams delivering 3D experiences across Android, iOS and Web where scenes can be described in code; those wanting console-grade rendering or with existing native 3D teams are not the audience. Facts and limits: Apache-2.0, TypeScript, created October 2026 with just 200 stars — very early; “native rendering” performance and consistency need per-scene validation; Google-authored but not a flagship product line, so cadence is unproven. It forms an upstream/downstream pair with local 3D-generation entries like Modly on this site — one generates the model, one renders and distributes it.