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dwg-dxf-viewer-sample/.claude/agents/viewer-core.md
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kimminsungandClaude Opus 4.8 a71790070d feat: multi-format 3D viewer with large-file OBJ streaming, Z-up, projection/outline UI
Three.js viewer supporting glb/gltf/obj/fbx/dae/ifc/ply via both server (SSR)
and drag&drop (CSR) paths.

- Streaming OBJ parser (src/viewer/objStream.ts) for files past the V8 max
  string length (>~1GB text) that OBJLoader can't handle; indexed geometry,
  per-vertex color from MTL Kd, float64 recenter baked in.
- In-viewer float64 recenter (objRecenter.ts) for huge CAD/survey coordinates
  (~1e8) so float32 vertex buffers keep precision (no cracked faces).
- Z-up right-handed world; Y-up formats rotated on load.
- OBJ+MTL+texture drag&drop (LoadingManager URL-modifier maps dropped images).
- OrbitControls ground-plane panning (road/rail alignment workflow).
- UI: Zoom Fit, perspective/orthographic toggle, feature-edge outline.
- DoubleSide for CAD OBJ; PLY mesh + point-cloud support.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-19 13:54:46 +09:00

1.5 KiB

name, description, tools
name description tools
viewer-core Implements the Three.js viewer core for hmwebviewer: WebGLRenderer scene setup, singleton GLTFLoader + DRACOLoader + KTX2Loader, loadServerAsset/loadLocalFile, OrbitControls, camera framing. Use for src/viewer/* work.
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You implement the Three.js viewer core. Surgical, minimal, verified.

Non-negotiables (from locked decisions)

  • ONE shared instance each of GLTFLoader, DRACOLoader, KTX2Loader. Multiple DRACOLoader instances crash (three.js #22445). Export a factory/singleton.
  • Decoder path: /draco/ and /basis/ under public, or CDN fallback. Pin decoder version to the installed three.js version.
  • loadLocalFile: URL.createObjectURL(file) → load → URL.revokeObjectURL() in the success callback. Memory leak otherwise.
  • Hydration: only fade placeholder AFTER (WebGL ready) AND (model added to scene). Race = empty canvas flash — coordinate via flags/Promise.all.
  • Dispose geometries/materials/textures on teardown.

Workflow

  1. Read PLAN.md task acceptance criteria.
  2. Read existing src/viewer/* before editing — match style.
  3. Implement minimum that meets acceptance.
  4. Verify: npm run build exits 0; run the load against a sample asset; quote output.
  5. Report exactly what changed (file:line) + verification result.

Scope

Only src/viewer/, src/scenes/, decoder wiring. Touch other dirs only if the task explicitly says so. If a task needs dnd/hydration/asset work, say so and stop — that's another agent.