fix(examples): redesign prop-origin-transform as a street utility pedestal with a thrown conduit elbow (#267)

* fix(examples): redesign prop-origin-transform as a street utility pedestal with a thrown conduit elbow

The gallery review judged the hero programmer art: two teal boxes with grey
cylinders, cryptic TRAP / MPI KEEP floor text and unexplained tick marks.

The pedestal is now a designed prop in five materials: concrete footing,
galvanised base plate and anchor nuts, cabinet with kick skirt, hipped lid,
hinged door with a T-handle and hazard plate, louvred vents, a conduit boss
and a pad sleeve. It is authored as an import arrives (centred origin, mesh
divided by a non-uniform object scale), so the data-API bake lands on
exactly the designed shape. The accessory is a flanged PVC conduit elbow
with a clamp and a coupling that seats in the sleeve.

The composition drops all text. The left copy is parented with MPI and
seated. On the right copy, bare child.parent throws the elbow 0.65 m into
the air past the slab edge, and a glowing cyan wireframe ghost marks the
seat it left. Floor pivot rings centred on each origin replace the axis
stubs. The render path now runs the gallery_asset_quality gate too, and
asset_sheet.py gains a SELECT row for the asset.

Check logic and thresholds are unchanged. The documented numbers move with
the new mesh: bare jump 0.298 m, and min.z -0.58 without the origin bake.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Signed-off-by: TMHSDigital <154358121+TMHSDigital@users.noreply.github.com>

* fix(examples): shorten prop-origin-transform alt and regenerate gallery

build_gallery caps card alts at 200 chars; the redesign alt was 333.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Signed-off-by: TMHSDigital <154358121+TMHSDigital@users.noreply.github.com>

---------

Signed-off-by: TMHSDigital <154358121+TMHSDigital@users.noreply.github.com>
Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Author: TMHSDigital

README.md

@@ -1010,7 +1010,7 @@ still: DIRTY through-hole + loose-vert bead vs CLEAN manifold (same brass).
 </tr>
 <tr>
 <td width="46%" valign="middle">
-<a href="examples/prop-origin-transform/"><img src="examples/prop-origin-transform/preview.webp" alt="Prop origin transform: dual-panel TRAP vs MPI KEEP street pedestals with margins all around — left bare-parent conduit accessory teleports off its dark mount well, right accessory stays seated, origin axes crossing on the floor under each base — proving scale apply, base origin, and matrix_parent_inverse" /></a>
+<a href="examples/prop-origin-transform/"><img src="examples/prop-origin-transform/preview.webp" alt="Prop origin transform: two green street utility pedestals, each centred in a floor pivot ring — left, the orange conduit elbow parented with matrix_parent_inverse stays bolted to its mount; right, bare child.parent = parent throws the elbow into the air beyond the slab while a glowing cyan outline marks its empty seat — proving scale apply, base origin, and matrix_parent_inverse" /></a>
 </td>
 <td valign="middle">
 
@@ -1019,7 +1019,7 @@ still: DIRTY through-hole + loose-vert bead vs CLEAN manifold (same brass).
 The origin / scale-apply / MPI contract a prop pipeline relies on before
 engine ingest: data-API scale bake to exactly `(1,1,1)`, local bbox
 `min.z == 0` (origin at base), world AABB unchanged across the bake, and
-`matrix_parent_inverse` so a flanged conduit stays on its mount socket.
+`matrix_parent_inverse` so a flanged conduit elbow stays on its mount.
 Extends [`parent-inverse-orrery`](examples/parent-inverse-orrery/) without
 retreading orbits. Dual-panel still: TRAP (bare parent — empty socket +
 teleported flange) vs MPI KEEP.

docs/gallery/asset-sheets/prop-origin-transform.webp

@@ -750,11 +750,11 @@ <h2><a href="mesh-hygiene-audit/">mesh-hygiene-audit</a></h2>
       </article>
       <article class="card" data-tags="transforms parenting game-pipeline">
         <a class="card-media" href="prop-origin-transform/" tabindex="-1" aria-hidden="true">
-          <img src="assets/prop-origin-transform-hero.webp" alt="Two teal pedestals labelled TRAP and MPI KEEP, origin axes crossing on the floor under each base: on the left a conduit fitting has jumped out of its socket, on the right it sits seated." loading="lazy" decoding="async" />
+          <img src="assets/prop-origin-transform-hero.webp" alt="Two green street utility pedestals in floor pivot rings: the left one keeps its orange conduit elbow bolted on, the right one&#x27;s elbow hangs in the air beside a glowing cyan outline of its seat." loading="lazy" decoding="async" />
         </a>
         <div class="card-body">
           <h2><a href="prop-origin-transform/">prop-origin-transform</a></h2>
-          <p class="teaches">Street pedestal origin-to-base-center + data-API scale apply + matrix_parent_inverse for a flanged conduit accessory. After bake: scale (1,1,1), local min.z==0, world AABB unchanged. Bare parent jumps the accessory off an empty mount socket; MPI keeps it seated.</p>
+          <p class="teaches">Street pedestal origin-to-base-center + data-API scale apply + matrix_parent_inverse for a flanged conduit elbow. After bake: scale (1,1,1), local min.z==0, world AABB unchanged. Bare parent throws the elbow off its mount; MPI keeps it seated.</p>
           <p class="witnesses"><span class="tag">witnesses</span> Bare child.parent = parent teleports accessories off their mounts; skipping view_layer.update() before matrix_world, or leaving non-uniform scale / centered origin, breaks engine ingest placement.</p>
           <a class="card-link" href="prop-origin-transform/">View example<span class="sr-only"> prop-origin-transform</span> <span aria-hidden="true">&rarr;</span></a>
         </div>

docs/gallery/assets/prop-origin-transform-hero.webp

@@ -501,8 +501,8 @@
     {
       "name": "prop-origin-transform",
       "dir": "examples/prop-origin-transform",
-      "teaches": "Street pedestal origin-to-base-center + data-API scale apply + matrix_parent_inverse for a flanged conduit accessory. After bake: scale (1,1,1), local min.z==0, world AABB unchanged. Bare parent jumps the accessory off an empty mount socket; MPI keeps it seated.",
-      "alt": "Two teal pedestals labelled TRAP and MPI KEEP, origin axes crossing on the floor under each base: on the left a conduit fitting has jumped out of its socket, on the right it sits seated.",
+      "teaches": "Street pedestal origin-to-base-center + data-API scale apply + matrix_parent_inverse for a flanged conduit elbow. After bake: scale (1,1,1), local min.z==0, world AABB unchanged. Bare parent throws the elbow off its mount; MPI keeps it seated.",
+      "alt": "Two green street utility pedestals in floor pivot rings: the left one keeps its orange conduit elbow bolted on, the right one's elbow hangs in the air beside a glowing cyan outline of its seat.",
       "witnessesFix": "Bare child.parent = parent teleports accessories off their mounts; skipping view_layer.update() before matrix_world, or leaving non-uniform scale / centered origin, breaks engine ingest placement.",
       "hero": "docs/gallery/assets/prop-origin-transform-hero.webp",
       "preview": "examples/prop-origin-transform/preview.webp",

docs/gallery/contact-sheets/prop-origin-transform-contact-sheet.webp

@@ -1,7 +1,7 @@
 # Prop Origin Transform
 
-A runnable example that builds a street utility pedestal with a bolted
-conduit accessory and proves the **origin / scale-apply / MPI** contract a
+A runnable example that builds a street utility pedestal with a flanged
+conduit elbow and proves the **origin / scale-apply / MPI** contract a
 prop pipeline relies on before engine ingest — following
 [`operators`](../../skills/operators/SKILL.md) and the data-API parenting
 idiom from [`parent-inverse-orrery`](../parent-inverse-orrery/).
@@ -27,24 +27,37 @@ engine exporter — it proves the transform properties such an asset must have.
 - **Origin at base center.** Local bbox `min.z == 0`, XY centered; world AABB
   delta across the bake is **0** (gate `1e-5`).
 - **Bare-parent trap.** Parenting the accessory without MPI jumps it
-  (~0.43 m measured); setting `matrix_parent_inverse` restores world location
-  (err ~3e-8).
+  (0.298 m measured); setting `matrix_parent_inverse` restores world
+  location (err 0).
 
 **What each check catches on failure:** skipping scale apply leaves
-non-identity scale; skipping origin bake leaves `min.z ≈ -0.756`; skipping
-MPI leaves the accessory teleported.
+`(1.15, 0.92, 1.08)` (exit 5); skipping the origin bake leaves
+`min.z = -0.58` (exit 6); skipping MPI leaves the accessory 0.298 m off
+(exit 8).
 
-**Version witness:** byte-identical numbers on Blender 4.5.11 LTS and 5.1.2.
+**Version witness:** identical numbers on Blender 5.2.1 LTS, 5.1.2 and
+4.5.11 LTS.
 
-The render is a dual panel: left **TRAP** (bare parent — flanged conduit
-teleports off a deep shadowed mount socket) vs right **MPI KEEP** (same metal
-fitting seated in the socket), with emissive origin markers at each pedestal's
-base. The origin is inside the plinth, so the red X and green Y stubs are
-centred on it and run 1.7 m along the floor, exiting the plinth on both
-sides: where they cross, under the base, is the origin. The first cut drew
-0.28 m stubs from the origin outward, all buried, and 0.11 m labels that
-vanished at card size; the labels are 0.21 m now. Accessory and pedestal stay in one material family so displacement — not
-color — carries the proof. Check closed forms are unchanged.
+**The asset.** The pedestal is one mesh with five materials: a precast concrete footing,
+a galvanised base plate with anchor nuts, a green cabinet on a black kick
+skirt, a hipped lid, a door with hinges, a T-handle and a hazard plate, louvred
+side vents, a conduit boss on the +X face and a sleeve in the pad. It is
+authored the way an import often arrives: origin at the geometric centre and
+coordinates divided by a non-uniform object scale. The bake lands it on
+exactly the designed shape. The accessory is a flanged PVC conduit elbow
+with bolt heads, a strap clamp and a coupling that drops into the sleeve.
+
+**The render.** Two baked pedestals stand on a sidewalk slab. On the left the elbow is
+parented with MPI and stays bolted to its boss, seated in the sleeve. On the
+right, bare `child.parent = parent` applies the pedestal's transform a
+second time. The elbow is thrown 0.65 m, past the slab edge and into the
+air, and a glowing cyan outline (a Wireframe modifier on a copy)
+marks the seat it left. The slab raises both origins 0.20 m, so the doubled
+translation lifts the elbow instead of sliding it along the floor. A
+pivot ring on the floor is centred on each pedestal's origin, with red
+notches on its X axis and green notches on Y. The origin is under the base,
+so the ring frames it. There are no text labels: the ghost and the stranded
+elbow carry the proof. The check's closed forms are unchanged.
 
 ## Run
 
@@ -73,6 +86,7 @@ against it. `10` is the shared framing helper.
 | 8 | MPI did not restore world location (`--skip-mpi` lands here) |
 | 9 | `--output` produced no file |
 | 10 | Gallery framing violation |
+| 11 | Gallery asset-quality violation (render path only) |
 
 The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
 (5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).