Iwsdk Scene Composer

IWSDK Scene Composer

Author native IWSDK assets and scene files. Application code owns geometry and materials; scene JSON owns composition; the managed editor provides visual feedback and human transform/component adjustment.

Read these references when relevant:

• scene-format.md before editing scene JSON;
• asset-authoring.md before creating or changing glTF or procedural assets;
• text-intake.md for text-only requests;
• image-intake.md for image or hybrid requests;
• composition-patterns.md for decomposition and repetition strategies;
• review-and-stop.md before final review.

Fixed Boundaries

• Use only iwsdk.scene.v1. There is no compatibility schema.
• Scene files are the composition source of truth. Create and edit them with normal filesystem tools under public/scenes/.
• Scene JSON has one renderable content kind: asset. It does not define models, primitive geometry, material resources, or material overrides.
• The default export of the configured application asset manifest is the asset source of truth. It may contain URL-backed glTF and UIKitML entries plus parentless Object3D prototypes with arbitrary Three.js geometry and materials.
• The application runtime and editor import the same manifest module independently. Never depend on shared object identity, iframe messaging, DOM state, or a live runtime world when defining assets.
• Humans use the editor for selection, hierarchy, transforms, components, root lighting, and preview visibility. They do not edit geometry or materials there.
• Agents may edit asset TypeScript and scene JSON, then use the editor to validate and render the result.

The public scene MCP surface is intentionally small:

scene_open
scene_render_file
scene_flatten_file
scene_get_state
scene_get_capabilities
scene_screenshot
scene_select
scene_set_camera
scene_set_preview_visibility
scene_measure_image_regions

Document creation and mutation happen through direct file edits. Do not look for MCP create/add/update/remove/patch/save/compose/review/publish tools.

When MCP is unavailable, use the CLI equivalents:

npx iwsdk dev status
npx iwsdk dev up
npx iwsdk scene capabilities --raw
npx iwsdk scene render-file \
  --input-json '{"path":"public/scenes/room.iwsdk.scene.json","viewId":"hero"}' \
  --output-file artifacts/room.png
npx iwsdk scene flatten \
  --input-json '{"path":"public/scenes/room.composition.iwsdk.scene.json","outputPath":"public/scenes/room.iwsdk.scene.json"}' --raw
npx iwsdk scene open \
  --input-json '{"path":"public/scenes/room.iwsdk.scene.json"}' --raw
npx iwsdk scene state --raw

iwsdk dev up starts the server in the background, launches the configured managed editor browser, and waits for the command bridge. Do not edit vite.config.ts to change browser mode as an ad hoc startup workaround.

scene_render_file renders a file without replacing the editor's active document, but it still uses the managed editor browser for manifest evaluation and WebGL. If startup reports dev_browser_not_ready, inspect iwsdk dev status and iwsdk dev logs --tail 100. Retry only when the diagnostics indicate a transient startup failure. Do not invent a custom CPU or Playwright renderer and present it as authoritative editor evidence. Preserve the structured failure, continue type/schema/build checks that remain meaningful, and report the visual-verification gate as blocked.

Camera parameters are intentionally distinct: view accepts only the built-in presets (current, top, front, back, left, right, quarter, orbit), while viewId selects an exact camera declared in authoring.views. Outside immersive XR, a loaded level's saved hero view owns runtime framing and supersedes the initial World.create({ render: { camera } }) pose. In XR, the tracked player rig owns the camera, so the player-spawn view is a separate required framing check.

Workflow

1. Specify

Turn the request into a compact implementation brief:

• required and optional features;
• source evidence regions for image input;
• silhouette, proportions, parts, negative space, contacts, and material response;
• hero and diagnostic views;
• measurable acceptance criteria;
• assumptions, uncertainty, and fidelity ceiling.

A single image proves visible composition, not hidden geometry. Do not silently invent occluded detail or lower requested fidelity.

2. Plan Assets And Modules

Call scene_get_capabilities once. Inspect src/assets.ts and existing asset modules.

Choose an external asset source deliberately:

• Use the configured MetaVR asset search, or npx @meta-quest/metavr --json asset search "<query>", for ready-made static props and background dressing. Results provide previews plus GLB/FBX downloads, but do not promise semantic subparts, rigging, articulation, or independently editable pieces. Inspect the downloaded hierarchy, and copy selected files into project-owned storage instead of persisting a returned CDN URL.
• Use npx @drawcall/market skill and npx @drawcall/market types, then search a concrete need with npx @drawcall/market search "<query>" --type <type> --limit 3, when an installable reusable asset, template, or provider-generated result is a better starting point. Preview finalists and install the exact printed name@version; trust the install output for consumer paths.
• Drawcall Market is a marketplace/install/generation CLI, not a universal procedural-geometry engine. When the request depends on controllable parts, parametric dimensions, articulation, or code-driven variation and no suitable code-backed template exists, author a deterministic Three.js Object3D prototype.

For every visible form, choose one of:

1. reuse an existing manifest asset;
2. add a glTF entry to the manifest;
3. register a UIKitML file with AssetType.UIKitML;
4. create a deterministic parentless Object3D prototype in code and register it;
5. assemble existing assets with a scene prefab or module.

Create custom geometry and materials in asset code, not JSON. Prefer separate *.scene-asset.ts modules for substantial procedural assets and import their prototypes into src/assets.ts.

For initial construction, plan independent semantic groups as standalone scratch scene modules. Give each module a local origin, size envelope, attachment points, required views, and asset IDs. Asset and component IDs are application-global; imported node and prefab IDs are namespaced. Imports are an authoring-only assembly mechanism, never a runtime or editable-project format.

3. Build

Author assets first, then scene JSON. Build in dependency order:

1. support/stage and representative lighting;
2. large composition masses;
3. identity-critical groups;
4. repeated secondary detail;
5. hero camera and final environment.

Use meters, stable descriptive IDs, deterministic ordering, and explicit transforms. Groups supply hierarchy, never visible mass. Use castShadow and receiveShadow on asset nodes only when needed. Use prefabs and patterns for repetition; keep repeated asset prototypes resource-sharing friendly.

4. Validate And Materialize

With the managed editor command-ready, call scene_render_file on every changed scratch module, then the composition root. It resolves imports for authoring preview, validates schema and manifest references, lowers the scene, and returns a PNG plus diagnostics without changing the active document. Fix failures in the owning asset or scratch file.

After the composition root passes, run scene_flatten_file / iwsdk scene flatten once to materialize an import-free final scene. The command preserves import wrapper groups, validates the output, and refuses to write if its runtime hash differs from the composed source. This is a one-way publication boundary: the flat file becomes the sole source of truth, and later scratch-module changes must not be re-flattened over human edits.

Call scene_open only on the flattened file for live collaboration. Import-bearing files remain renderable composition previews but are never opened as editable scenes and never load in the application runtime.

Use scene_get_state for selection, hashes, diagnostics, dirty/conflict state, runtime readiness, and render statistics. Use camera, screenshot, selection, and preview visibility tools only when their live-editor context is useful.

5. Review And Refine

Review in three passes:

1. Layout: hierarchy, scale, support contacts, and arrangement.
2. Geometry: silhouette, proportions, parts, negative space, and alternate views.
3. Final: material response, color, lighting, environment, and hero framing.

Keep review orchestration and evidence outside the editor. The editor supplies authoritative screenshots, hashes, camera state, diagnostics, and render measurements. Derive comparisons, defect lists, lineage, and stop decisions in ordinary task files.

Fix the highest-impact defect in its owning asset or scene module, rerender that file, then rerender the root. Default to two focused correction rounds. Stop earlier on a repeated defect, oscillation, plateau, missing input/asset, or representation ceiling.

6. Finish

Finish only when:

• every scratch module and the composition root validates and renders;
• the final editable scene is flattened and contains no imports;
• the active editor state is clean and conflict-free;
• required views are nonblank and correctly framed;
• required features pass measurable and visual checks;
• manifest asset IDs resolve in both editor and application runtime;
• the application build and selected scene load without blocking errors.

If a required gate is unavailable, finish with an explicit blocked or accepted-with-gaps result. Passing a local schema check, production build, or custom diagnostic image does not substitute for authoritative editor renders and state.

Modular Composition

{
  "version": "iwsdk.scene.v1",
  "units": "meters",
  "imports": [
    {
      "id": "reading-nook",
      "src": "./modules/reading-nook.iwsdk.scene.json",
      "transform": { "position": [1.8, 0, -0.6] }
    }
  ],
  "resources": {},
  "nodes": []
}

Each scratch module must be valid by itself. Imports resolve recursively in declaration order. The import entry becomes a transform group. The composition root owns global components, environment, metadata, and authoring settings. Cycles, unsafe IDs, missing files, duplicate namespaced IDs, and invalid modules fail composition.

For parallel initial construction, assign one scratch module file per worker. Never let two workers edit one file. Render modules independently, import only passing modules, correct cross-module scale, contact, occlusion, lighting, and framing at the composition root, then flatten exactly once. Parallel module iteration ends at that boundary; continue all later edits in the flat file.

Regeneration And Provenance

Preserve stable IDs when revising the flat file. Never overwrite unrelated human-authored files or re-flatten over editor changes. Record the skill/runtime versions, input hashes, composition/final/module paths, capability hash, source/composed/runtime hashes, assumptions, and fidelity ceiling in authoring metadata or adjacent task evidence.