Babylon NOA Prototype Notes

Current Position

Nova64 has an experimental NOA probe seam at:

• runtime/backends/babylon/noa-prototype.js

Nova64 also has an opt-in adapter at:

• runtime/backends/babylon/noa-adapter.js

This is intentionally not a full runtime swap. The default Babylon voxel path still lives in:

• runtime/backends/babylon/voxel.js
• runtime/api-voxel.js

The shared Nova64 voxel API remains the canonical cart-facing contract.

Why The Prototype Is Guarded

noa-engine is promising because it is Babylon-native, but it is also a larger engine with its own world, registry, entity, and render ownership model.

Two practical constraints matter right now:

1. Nova64 already owns world generation, chunk lifecycles, entities, and cart-facing voxel APIs in runtime/api-voxel.js.
2. The published package is currently noa-engine@0.33.0, and its npm peer dependency still targets @babylonjs/core ^6.1.0, while Nova64 is on Babylon 7.

Because of that, the current integration point is probe-first instead of takeover-first.

What Exists Today

The prototype exposes two shared voxel diagnostics:

• getVoxelNoaPrototypeStatus()
• probeVoxelNoaPrototype()

These are available through flat globals and nova64.voxel.*.

On Babylon:

• ?noaVoxel=1 or ?noaVoxel=probe requests a probe on boot.
• localStorage['nova64:noaVoxel'] = '1' also requests a probe.
• globalThis.NOVA64_NOA_PROTOTYPE = true can request a probe before runtime boot.

The probe attempts to load noa-engine and reports whether the module is available. The adapter APIs are separate and opt-in so the default Babylon renderer remains stable.

Adapter Controls

The experimental adapter exposes these controls through flat globals and nova64.voxel.*:

• enableVoxelNoaAdapter(options)
• disableVoxelNoaAdapter()
• getVoxelNoaAdapterStatus()
• isVoxelNoaActive()

Keep these guarded. They should report inactive status gracefully when NOA is unavailable or incompatible.

Expected Status Values

Typical reason values from getVoxelNoaPrototypeStatus():

• disabled
• unsupported-backend
• requested-pending
• dependency-missing
• loaded-awaiting-adapter

active should stay false for probe-only status. Adapter status is reported separately by getVoxelNoaAdapterStatus().

Next Safe Steps

1. Keep validating minecraft-demo and voxel-creatures first.
2. Prototype one isolated concern at a time:
   • chunk meshing
   • chunk streaming / world paging
   • collision / entity movement
3. Keep Nova64 carts on the existing shared voxel API while experimenting behind the Babylon seam.
4. Do not add cart-level if (backend === 'babylon') NOA branches.
5. Test build stability first when touching the adapter because noa-engine@0.33.0 predates Nova64's current Babylon line.

Validation

Use these first when touching the prototype seam:

• pnpm test:babylon:api
• pnpm exec playwright test tests/playwright/wad-vox-regression.spec.js --grep "Voxel Regression" --reporter=line
• pnpm exec playwright test tests/playwright/backend-parity.spec.js --grep "Voxel" --reporter=line

If the probe seam changes, keep the fallback path graceful: Babylon should continue using Nova64's built-in voxel renderer when NOA is unavailable.