glb-web-handoff

Purpose

Define reliable handoff language and checks for GLB/web scenarios without overclaiming.

Quick start

• confirm this skill fits your goal
• provide required inputs first
• keep runtime claims evidence-bound
• follow suggested next-skill handoff

When to use

• when writing the GLB/web handoff summary after upstream validation from scene-readiness and evidence classification from render-export-evidence
• when summarizing per-artifact export statuses and web compatibility assumptions/caveats (transform/scale/origin, material/texture portability, loader/extensions, stack, performance)
• when preparing truthful next checks before passing final wording to plain-language-response

When not to use

• to claim GLB or export success without concrete evidence → use ../scene-readiness/SKILL.md (Delegates out-of-scope requests to scene-readiness)
• to replace runtime export verification → use ../render-export-evidence/SKILL.md (Delegates out-of-scope requests to render-export-evidence)
• to validate upstream scene readiness → use ../scene-readiness/SKILL.md (use scene-readiness)
• to classify raw render/export artifact evidence → use ../render-export-evidence/SKILL.md (use render-export-evidence)
• to define mobile or file-size performance budgets → use ../mobile-glb-budget/SKILL.md (use mobile-glb-budget)
• to define animation playback or rig contracts → use ../glb-animation-handoff/SKILL.md (use glb-animation-handoff)
• to write the final user-facing response wording → use ../plain-language-response/SKILL.md (use plain-language-response)

Trigger phrases

• "prepare web handoff"
• "is GLB ready"
• "summarize export status"

Prerequisites / readiness

• upstream readiness output from scene-readiness available (or marked unverified)
• classified artifact evidence state from render-export-evidence known
• runtime mode known (within the 2-path + CLI appendix runtime model)

Input schema

Required inputs

• per-artifact status evidence from render-export-evidence (with provenance to the current run for any pre-existing files)
• upstream readiness summary from scene-readiness
• handoff target context and known compatibility assumptions

Optional inputs

• size/performance budget outputs from mobile-glb-budget
• animation handoff notes from glb-animation-handoff
• expected downstream web stack details

Assumptions to confirm

• transform/scale/origin assumptions
• material/texture portability assumptions
• loader/extensions assumptions
• target web stack assumptions
• performance assumptions and caveats
• truth states are downgrade-only (never upgrade):
  • Runtime: Not Run | Attempted | Produced | Verified | Failed
  • Artifacts: Not Run | Not Produced | Produced | Verified | Failed (default Not Produced)

Output schema

Primary output

• truthful GLB/web handoff summary with explicit Runtime status and per-artifact statuses

Secondary output

• compatibility assumptions and caveats covering transform/scale/origin, material/texture portability, loader/extensions, stack, and performance

Evidence / caveat output

• explicit Runtime status (Not Run | Attempted | Produced | Verified | Failed) and per-artifact status (Not Run | Not Produced | Produced | Verified | Failed, default Not Produced), downgrade-only
• provenance confirmation tying any Produced or Verified artifact to the current run
• unresolved risk notes, next checks, and cross-skill handoffs

Required laws

• ../../laws/evidence-before-done.md
• ../../laws/official-runtime-only.md
• ../../laws/non-blender-user-language.md
• ../../laws/no-arbitrary-python-interface.md

Official runtime boundary

Never claim GLB or export success without concrete evidence tied to the current run, and never replace runtime export verification. Keep runtime vocabulary strictly within the 2-path (Path 1 Official Blender Lab MCP 5.1+, Path 2 community mcp-for-blender) + CLI appendix model. This skill never runs Blender or Python and never upgrades Runtime or Artifact truth states (downgrade-only).

Operating procedure

1. Enumerate expected handoff artifacts (GLB, preview renders, reports) and check current-run provenance for any pre-existing files.
2. Inspect the GLB 2.0 binary container with scripts/inspect-glb.mjs (blendops glb-inspect) and generate/validate the structured handoff manifest (schemas/glb-web-handoff-manifest.schema.json) via scripts/generate-glb-handoff-report.mjs (blendops glb-handoff) across all four validation tiers (Tier 1 Container Structural, Tier 2 Khronos glTF 2.0 Specification, Tier 3 Visual Quality, Tier 4 Live Blender Runtime).
3. Record Runtime status (Not Run | Attempted | Produced | Verified | Failed) and mark each artifact status (Not Produced | Produced | Verified | Failed, default Not Produced) using render-export-evidence without upgrading any state.
4. Document transform/scale/origin assumptions and caveats (+Y up, +Z forward, -X right, 1 unit = 1 meter, non-identity or negative root scale checks).
5. Document material/texture portability assumptions and caveats (embedded bufferView vs external URI textures, KTX2/WebP transcoders, alpha modes).
6. Document loader/extensions and target web stack compatibility assumptions (DRACOLoader, MeshoptDecoder, KTX2Loader, Three.js / React Three Fiber integration modules in docs/examples/glb-web-handoff/README.md) without inventing unsupported guarantees.
7. Document performance caveats and uncertainty (incorporating mobile-glb-budget if size budgets apply, and glb-animation-handoff if animation contracts apply).
8. Verify compliance with evidence boundaries and upstream scene-readiness findings, then hand off to plain-language-response for final user-facing wording.

Decision tree

• If concrete current-run GLB evidence is classified by render-export-evidence -> report Produced or Verified (matching evidence, never upgraded) + full compatibility caveats.
• If a GLB file exists on disk but lacks provenance to the current run -> do not claim Produced or Verified; downgrade to Not Produced with a provenance caveat.
• If runtime was not executed -> mark Runtime Not Run and artifacts Not Run or default Not Produced.
• If runtime was Attempted or Failed and no valid GLB was exported -> mark artifact Not Produced or Failed with failure notes and next checks.
• If size budgets or animation contracts are needed -> route to mobile-glb-budget or glb-animation-handoff respectively.
• Once handoff summary is complete -> hand off to plain-language-response for final user-facing wording.

Playbooks

• Playbook A: text-only planning path
• Playbook B: runtime-ready path with evidence gating
• Playbook C: blocked runtime path with caveat-first reporting

Mode handling

Text-only mode

• document handoff expectations, compatibility assumptions, and caveats only
• mark Runtime Not Run and artifacts Not Run or Not Produced (default Not Produced)

Runtime-ready mode

• report evidence-linked Runtime status (Not Run | Attempted | Produced | Verified | Failed) and per-artifact statuses (Not Run | Not Produced | Produced | Verified | Failed, default Not Produced) with current-run provenance and downgrade-only enforcement

Blocked runtime mode

• make zero production or verification claims; keep artifacts at Not Produced, Not Run, or Failed
• provide blocker-driven next checks and compatibility caveats

Validation checklist

• Runtime status (Not Run | Attempted | Produced | Verified | Failed) explicit
• GLB and preview per-artifact statuses (Not Produced | Produced | Verified | Failed, default Not Produced) explicit
• current-run provenance verified for any pre-existing files (synthetic test fixtures remain Not Produced)
• truth states strictly downgrade-only (never upgraded)
• 4-tier validation summary explicit (Container Structural, glTF 2.0 Specification, Visual Quality, Live Runtime)
• transform/scale/origin assumptions documented
• material/texture portability caveats documented
• loader/extensions assumptions documented (DRACOLoader, MeshoptDecoder, KTX2Loader)
• target stack assumptions documented (threejs, react-three-fiber, model-viewer, babylonjs)
• performance caveats documented
• no unsupported readiness guarantees or role blur with evidence/quality/budget/animation/response skills
• actionable next checks and handoff to plain-language-response included

Pass / Warn / Fail rubric

Failure handling

• Missing evidence: mark Runtime Not Run (or Attempted) and artifacts Not Produced (default) or Not Run, then route to render-export-evidence / list missing checks.
• Failed export evidence: mark Runtime/artifact Failed or Not Produced (downgrade-only), record failure reason, and list next checks.
• Pre-existing file without current-run provenance: refuse Produced/Verified status, keep at Not Produced, and require a fresh verified export run.
• Unknown compatibility in any of the 5 categories: mark Warn with an explicit caveat rather than assuming support.

Troubleshooting

• Existing files found: verify provenance before claiming produced.
• Missing scale/origin assumptions: add as blocker.
• Missing stack assumptions: mark handoff as conditional.

Best practices

• Always pair every per-artifact status with its matching compatibility caveats.
• Enforce downgrade-only truth states and verify current-run provenance before accepting any file as Produced or Verified.
• Keep handoff notes in plain language and hand off final user-facing phrasing to plain-language-response.

Good examples

"Runtime status: Not Run. Artifact statuses: GLB Not Produced (default), Preview Not Produced. Compatibility assumptions & caveats: transform/scale/origin (1 unit = 1m, Z-up to Y-up conversion unverified), material/texture portability (procedural nodes must be baked before GLB export), loader/extensions (unverified compression/extension support), stack (target web viewer unspecified), performance (draw-call and file-size budget unverified; route to mobile-glb-budget if constrained). Next checks: run export via configured runtime path, classify evidence with render-export-evidence, and pass summary to plain-language-response."

Bad examples

“GLB is ready for production.” (no artifact proof)

User-facing response template

• Runtime status (Not Run | Attempted | Produced | Verified | Failed)
• Per-artifact statuses (Not Run | Not Produced | Produced | Verified | Failed, default Not Produced) with current-run provenance notes
• Compatibility assumptions and caveats:
  • Transform / scale / origin
  • Material / texture portability
  • Loader / extensions
  • Target stack
  • Performance
• Unverified risks and next checks
• Cross-skill handoff (to plain-language-response for final user-facing wording)

Anti-patterns

• skipping required laws or runtime boundary statements
• claiming runtime/artifact success without evidence
• using non-official runtime setup paths
• producing jargon-heavy final output without explanation

Cross-skill handoff

• [upstream_reference] Upstream scene readiness validation → ../scene-readiness/SKILL.md
• [upstream_reference] Upstream artifact evidence classification → ../render-export-evidence/SKILL.md
• [upstream_reference] Mobile and file-size budget constraints → ../mobile-glb-budget/SKILL.md
• [upstream_reference] Animation playback and rig handoff contracts → ../glb-animation-handoff/SKILL.md
• [progression] Final user-facing response wording → ../plain-language-response/SKILL.md

Non-goals

• Generating Python scripts or executing Blender exports
• Replacing runtime export verification
• Upgrading Runtime or Artifact truth states or accepting pre-existing files without current-run provenance
• Classifying raw render/export evidence (render-export-evidence) or validating upstream scene quality (scene-readiness)
• Defining size budgets (mobile-glb-budget), animation contracts (glb-animation-handoff), or final user-facing wording (plain-language-response)
• Making unsupported web stack or loader compatibility guarantees

References

• https://www.blender.org/lab/mcp-server/
• https://claude.com/resources/tutorials/using-the-blender-connector-in-claude
• https://docs.blender.org/manual/en/latest/advanced/command_line/index.html
• ../../schemas/glb-web-handoff-manifest.schema.json
• ../../scripts/inspect-glb.mjs
• ../../scripts/generate-glb-handoff-report.mjs
• ../../docs/examples/glb-web-handoff/README.md