# M03-RND-M2-STATIC-BATCH-MATERIALIZER-001

<!-- OPENWC_CLAIM:M03-RND-M2-STATIC-BATCH-MATERIALIZER-001:sindo-main-codex:2026-07-20 -->

## Owner

- Agent ID: `sindo-main-codex`
- Target: M03 Renderer Facade and Safe Extraction
- Branch: `work/sindo-main-codex/m03-m2-static-batch-materializer`
- Worktree: `C:\Users\sindo\open-wc-worktrees\m03-m2-static-batch-materializer`

## Outcome

Extract main-thread static M2 `MultiMesh` construction, render-property setup
and batch attachment from `StreamingWorldLoader`.

## Non-goals

- Change M2 grouping, batch sizing, build cursors, budgets or retry behavior.
- Change Mesh loading, refresh, cache ownership or missing-model outcomes.
- Own animated M2 instances, Editor persistence or tile cleanup.
- Introduce spatial cells or change transform order, visibility or shadows.

## Paths

- Exclusive: `src/render/m2/m2_static_batch_materializer.gd`,
  `src/tools/verify_m2_static_batch_materializer.gd`,
  `docs/modules/m2-static-batch-materializer.md`, this claim
- Shared/hotspots: `src/scenes/streaming/streaming_world_loader.gd`, M2 build/
  Mesh-cache/facade/internal-access/manifest verifiers and specs,
  `docs/modules/world-renderer.md`, `docs/modules/README.md`, `RENDER.md`,
  `targets/03-renderer-facade.md`
- Generated/ignored: `.godot`, native DLL, generated resources/caches and proprietary corpus

## Contracts and data

- `MultiMesh.TRANSFORM_3D`, exact Mesh identity, instance count and transform
  slice order remain unchanged.
- Batch node name remains model basename plus serial.
- Visibility end/margin and shadow setting remain exact renderer inputs.
- A valid batch attaches once to the supplied M2 parent and returns its node.
- Loader retains Editor-owner assignment, build cursor, budgets and retries.

## Dependencies

- Requires: accepted animated materializer package on master `86814de`
- Blocks: further M2 build-job orchestration extraction
- External state: Godot MultiMesh and SceneTree mutation remain main-thread APIs

## Verification

- Commands: dedicated invalid/name/mesh/count/order/render/attachment/source/timing
  verifier; M2 build/cache/prototype/animated/shutdown/material/facade/internal-
  access/manifest regressions; docs/coordination/dry-run gates
- Fixtures: synthetic ArrayMesh and ordered Transform3D slices
- Fidelity evidence: exact existing MultiMesh construction and render settings
- Performance budget: materialize 10,000 transforms under one second

## Documentation deliverables

- Inline API docs
- Module spec with inputs/outputs, ownership and source map
- Data-flow, lifecycle/state, sequence and dependency diagrams
- Adjacent build/cache/world-renderer/module-registry/RENDER updates

## Simplicity and naming

- Important name introduced: `M2StaticBatchMaterializer`
- Simplest solution: synchronous main-thread RefCounted returning attached node
- Rejected complexity: signals, async queue, callbacks and generic materializer base
- Unavoidable complexity: MultiMesh is a Godot Resource owned through its node
- Measured optimization evidence: bounded synthetic transform upload

## Status

- State: active
- Done: contract and ownership boundary
- Next: implementation, verification and documentation
- Blocked by:

## Handoff

- Commit:
- Results:
- Remaining risks:
- Documentation updated: