Scope: reference-based Char B1 bis with mechanical node rig, detachable fittings, damage swaps and independent wreck; exported GLBs rebuilt by one Blender script.
Cameras: front-left hero 1920x1080; orthographic left profile; identical hero clay; six paint and six damage states; mechanical pivot test.
Budgets: healthy 80–140k triangles and ≤12MB; damage ≤110k; ≤10 materials; textures ≤1024, ORM ≤512; exactly four damage roots.
Proof: delivery renders reimport both serialized GLBs into an empty Blender scene, Cycles OptiX. Runtime browser verification is supplementary if time allows.
Revision cap: three substantive geometry/material revisions, up to two image critiques per revision.
Started 18:23 CEST; healthy checkpoint about 18:53, damage about 19:23, final checkpoint 19:38 CEST.

Visual review: reference sheet inspected before authoring; three geometry/material passes inspected in Cycles, including side, rear, clay, six paint variants, six reimported damage states and moving-pivot proof.
Independent critic: Gemini forge:build-gemini-38flash returned REVISE then PASS after rounded howitzer mounting, thinner fender edges, cylindrical exhaust shrouds and frontal rivet detail. Its residual tail-hook concern came from front-only views; rear.png confirms Part_TailHook on the rear plate. Uniform procedural weathering remains a limitation.
Technical proof: all proof scenes import both delivered GLBs into an empty scene. The build manifest records the exact source SHA-256. Browser proof uses Three.js GLTFLoader and Chromium; dependencies and earlier review captures remain under /tmp.
Final acceptance: dimensions, texture budgets, exact Paint factor, mechanical parent relationships, 46 wheel pivots, once-around track UVs, 34 detachable parts, 17 matching damage twins and exactly four damage roots are checked from the serialized GLBs. Validation results are in validation.json.
Final files: healthy 123,958 triangles / 8,747,972 bytes; damage 99,288 triangles / 10,035,332 bytes. Khronos glTF validator: zero errors and zero warnings in both; ten informational empty nodes are required gameplay anchors. Browser: zero errors. Triangulated local meshes retain explicit tangents and all original mechanical pivots.