The blockout cleaning pass found the map was rendering with 604 of 620 mesh actors
unmaterialed - every kit piece and all theatre trim.
Cause: ensure_material() deleted and recreated each /Game/Hollywood/Site/M_* asset on
every run, so actors staged by other tools kept references to deleted assets and fell
back to the default material. Nothing errored; the map looked merely slightly flat.
- Materials are now updated IN PLACE (load, delete_all_material_expressions, rebuild
the graph, recompile, save). Material.expressions is protected from Python, so the
editing library's deleter is used.
- 53 duplicated kit actor labels fixed (both shop piers of a bay shared one name).
- New Tools/ue_audit_scene.py gates the scene: every mesh actor has a material, every
verified frontage span is within +/-1 m (via ue_placement), no duplicate labels.
- render_screenshots.sh now runs the chain in the required order (demo map -> kit ->
theatre -> audit -> cameras -> capture) and exits non-zero on an audit failure,
because the demo builder rebuilds materials and later staging must follow it.
Scene audit: 0 failures. Packaged QA PASS. Spawn-view reference score 0.72.
zwitschi
600633cd5b