Low-level rendering backends (Three.js, Babylon.js, WebGL2, Canvas2D)
Nova64 uses multiple GPU backends to provide flexible rendering options: Three.js as the primary 3D path, Babylon.js as the secondary parity backend, WebGL2 for lower-level rendering paths, and Canvas2D as a compatibility fallback.
See BACKEND_RUNTIME.md for the backend surface contract, Babylon compatibility layer, WAD mesh-proxy material assignment fix, vignette guard, voxel routing notes, and focused Playwright validation commands. Experimental NOA adapter notes live in BABYLON_NOA_INTEGRATION.md.