fix: wooden-ladder, wheelbarrow, curve-bevel-arc and sky-texture-sun-elevation quality pass

README.md

@@ -121,7 +121,7 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show
   <a href="showcase/watchtower/"><img src="showcase/watchtower/preview.webp" width="24%" alt="Watchtower: a timber lookout with X-braces, hatch ladder, plank platform, and a coursed shake roof on a dark studio floor" /></a>
   <a href="showcase/cart/"><img src="showcase/cart/preview.webp" width="24%" alt="Cart: a two-wheel wooden cart with spoked wheels, slatted bed, and shafts on a dark studio floor" /></a>
   <a href="showcase/park-bench/"><img src="showcase/park-bench/preview.webp" width="24%" alt="Park bench: a wrought-iron bench with scrolled legs and wooden slats on a dark studio floor" /></a>
-  <a href="showcase/wheelbarrow/"><img src="showcase/wheelbarrow/preview.webp" width="24%" alt="Wheelbarrow: a staved wooden tray with iron straps, a spoked wheel, rear legs, and handles on a dark studio floor" /></a>
+  <a href="showcase/wheelbarrow/"><img src="showcase/wheelbarrow/preview.webp" width="24%" alt="Wheelbarrow: a wooden tray with walls of stacked boards and iron straps, a spoked wheel, rear legs, and handles on a dark studio floor" /></a>
   <a href="showcase/anvil/"><img src="showcase/anvil/preview.webp" width="24%" alt="Anvil: a London-pattern anvil on a hooped timber stump on a dark studio floor" /></a>
   <a href="showcase/water-trough/"><img src="showcase/water-trough/preview.webp" width="24%" alt="Water trough: a watertight wooden trough with plank ends, contained water, and trestle legs on a dark studio floor" /></a>
   <a href="showcase/hitching-post/"><img src="showcase/hitching-post/preview.webp" width="24%" alt="Hitching post: a square timber post with a pyramidal cap, cross-arm, iron bands, and two hitching rings on a dark studio floor" /></a>
@@ -133,7 +133,7 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show
   <a href="showcase/wall-torch/"><img src="showcase/wall-torch/preview.webp" width="24%" alt="Wall torch: a dressed stone plaque with an iron sconce, wooden haft, and flame on a dark studio floor" /></a>
   <a href="showcase/tavern-stool/"><img src="showcase/tavern-stool/preview.webp" width="24%" alt="Tavern stool: a round wooden seat on turned splayed legs with stretchers and iron ferrules on a dark studio floor" /></a>
   <a href="showcase/iron-cauldron/"><img src="showcase/iron-cauldron/preview.webp" width="24%" alt="Iron cauldron: a round-bellied cast-iron pot hanging by its bail from a timber tripod on a dark studio floor" /></a>
-  <a href="showcase/wooden-ladder/"><img src="showcase/wooden-ladder/preview.webp" width="24%" alt="Wooden ladder: a raked timber ladder with six rungs and iron shoes on a dark studio floor" /></a>
+  <a href="showcase/wooden-ladder/"><img src="showcase/wooden-ladder/preview.webp" width="24%" alt="Wooden ladder: a raked timber ladder with six evenly spaced rungs and iron shoes, leaning against a dark wall section" /></a>
   <a href="showcase/hay-bale/"><img src="showcase/hay-bale/preview.webp" width="24%" alt="Hay bale: a bound straw bale with two sisal twine belts on a dark studio floor" /></a>
   <a href="showcase/crate-stack/"><img src="showcase/crate-stack/preview.webp" width="24%" alt="Crate stack: three slatted shipping crates stacked and yawed, each with iron corner straps and runners, on a dark studio floor" /></a>
   <a href="showcase/stone-archway/"><img src="showcase/stone-archway/preview.webp" width="24%" alt="Stone archway: a semicircular masonry arch with coursed piers, projecting imposts, nine voussoirs and a proud keystone, on a dark studio floor" /></a>
@@ -163,7 +163,7 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show
 
 [`park-bench`](showcase/park-bench/) — procedural wrought-iron park bench with scrolled legs and slatted seat through the same pipeline. Falsifier `--skip-decimate` exits 9.
 
-[`wheelbarrow`](showcase/wheelbarrow/) — procedural staved wheelbarrow with a spoked wheel, iron straps, legs, and handles through the same pipeline. Falsifier `--skip-decimate` exits 9.
+[`wheelbarrow`](showcase/wheelbarrow/) — procedural wheelbarrow with board-built tray walls, a spoked wheel, iron straps, legs, and handles through the same pipeline. Falsifiers `--skip-decimate` exits 9, `--wide-seams` exits 17.
 
 [`anvil`](showcase/anvil/) — procedural London-pattern anvil on a timber stump through the same pipeline. Falsifier `--skip-decimate` exits 9.
 
@@ -187,7 +187,7 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show
 
 [`iron-cauldron`](showcase/iron-cauldron/) — procedural round-bellied iron cauldron on a timber tripod through the same pipeline. Falsifiers `--skip-decimate` exits 9, `--pointed-pot` exits 19.
 
-[`wooden-ladder`](showcase/wooden-ladder/) — procedural timber ladder with raked stiles, rungs, and iron shoes through the same pipeline. Falsifier `--skip-decimate` exits 9.
+[`wooden-ladder`](showcase/wooden-ladder/) — procedural timber ladder with raked stiles, evenly pitched rungs, and iron shoes through the same pipeline. Falsifiers `--skip-decimate` exits 9, `--drift-rungs` exits 19.
 
 [`hay-bale`](showcase/hay-bale/) — procedural bound hay bale with sisal twine through the same pipeline. Falsifier `--skip-decimate` exits 9.
 
@@ -307,7 +307,7 @@ byte images stay straight 8-bit. Also witnesses `EXR color_mode='RGB'` dropping
 </tr>
 <tr>
 <td width="46%" valign="middle">
-<a href="examples/sky-texture-sun-elevation/"><img src="examples/sky-texture-sun-elevation/preview.webp" alt="Sky texture sun elevation: terracotta jar diptych on a dark floor — left panel low sun at 8 degrees with a deep blue zenith and warm horizon limb, right panel high sun at 55 degrees with a brighter cyan sky, proving ShaderNodeTexSky sun_elevation" /></a>
+<a href="examples/sky-texture-sun-elevation/"><img src="examples/sky-texture-sun-elevation/preview.webp" alt="Sky texture sun elevation: pale glazed jar diptych on a dark floor — left panel low sun at 8 degrees, the jar dim twilight blue under a deep blue zenith, right panel high sun at 55 degrees, the jar bright under a pale daylight sky" /></a>
 </td>
 <td valign="middle">
 
@@ -389,7 +389,7 @@ A relative Tall shape key that lifts and flares the top face — authored throug
 </tr>
 <tr>
 <td width="46%" valign="middle">
-<a href="examples/curve-bevel-arc/"><img src="examples/curve-bevel-arc/preview.webp" alt="Curve bevel arc: a rose beveled Bezier semicircle tube resting on a dark studio floor" /></a>
+<a href="examples/curve-bevel-arc/"><img src="examples/curve-bevel-arc/preview.webp" alt="Curve bevel arc: a rose beveled Bezier semicircle tube resting on a dark studio floor, both filled end caps facing the camera" /></a>
 </td>
 <td valign="middle">
 

docs/gallery/curve-bevel-arc/index.html

@@ -16,13 +16,13 @@
   <meta property="og:image" content="https://tmhsdigital.github.io/Blender-Developer-Tools/gallery/assets/curve-bevel-arc-hero.webp" />
   <meta property="og:image:width" content="1280" />
   <meta property="og:image:height" content="720" />
-  <meta property="og:image:alt" content="A magenta beveled curve tube sweeping in an arc across a dark floor, with a capped end." />
+  <meta property="og:image:alt" content="A magenta beveled curve tube lying in a semicircle on a dark floor, both filled end caps facing the camera." />
   <meta property="og:site_name" content="Blender Developer Tools" />
   <meta name="twitter:card" content="summary_large_image" />
   <meta name="twitter:title" content="curve-bevel-arc — Examples — Blender Developer Tools" />
   <meta name="twitter:description" content="A beveled Bezier semicircle authored on bpy.types.Curve — splines.new(&#x27;BEZIER&#x27;), bezier_points, bevel_depth, use_fill_caps — so the curve renders as a solid tube without a prior mesh conversion." />
   <meta name="twitter:image" content="https://tmhsdigital.github.io/Blender-Developer-Tools/gallery/assets/curve-bevel-arc-hero.webp" />
-  <meta name="twitter:image:alt" content="A magenta beveled curve tube sweeping in an arc across a dark floor, with a capped end." />
+  <meta name="twitter:image:alt" content="A magenta beveled curve tube lying in a semicircle on a dark floor, both filled end caps facing the camera." />
   <style>
     /* fonts are deployed by the landing build (docs/fonts/) */
     @font-face { font-family: 'Barlow Condensed'; font-weight: 600; font-display: swap;
@@ -268,8 +268,8 @@ <h1>curve-bevel-arc</h1>
     <p>A beveled Bezier semicircle authored on bpy.types.Curve — splines.new(&#x27;BEZIER&#x27;), bezier_points, bevel_depth, use_fill_caps — so the curve renders as a solid tube without a prior mesh conversion.</p>
   </header>
   <main id="main">
-    <button class="detail-hero" id="heroZoom" type="button" aria-label="View full size: A magenta beveled curve tube sweeping in an arc across a dark floor, with a capped end.">
-      <img src="../assets/curve-bevel-arc-hero.webp" alt="A magenta beveled curve tube sweeping in an arc across a dark floor, with a capped end." width="1280" height="720" />
+    <button class="detail-hero" id="heroZoom" type="button" aria-label="View full size: A magenta beveled curve tube lying in a semicircle on a dark floor, both filled end caps facing the camera.">
+      <img src="../assets/curve-bevel-arc-hero.webp" alt="A magenta beveled curve tube lying in a semicircle on a dark floor, both filled end caps facing the camera." width="1280" height="720" />
     </button>
     <p class="zoom-hint">Rendered headless by the example itself — click to zoom.</p>
     <div class="callout"><span class="tag">witnesses</span> Curve tubes are curve datablocks: eight Bezier points, bevel_depth == 0.15, filled caps, and the evaluated mesh has deterministic topology (1044 verts, 1028 faces) resting on the floor.</div>
@@ -280,6 +280,7 @@ <h1>curve-bevel-arc</h1>
     <section class="detail-section md">
 <p>A runnable example that builds a beveled Bezier semicircle entirely through the curve data API — <code>splines.new(&#x27;BEZIER&#x27;)</code>, per-point <code>bezier_points</code>, <code>bevel_depth</code>, and <code>use_fill_caps</code> — so the curve renders as a solid tube without a prior mesh conversion.</p>
 <p><strong>What it witnesses:</strong> renderable curve tubes are curve datablocks, not meshes. The check asserts eight Bezier points, <code>bevel_depth == 0.15</code>, <code>use_fill_caps</code>, and that the depsgraph-evaluated mesh has the deterministic topology (1044 verts, 1028 faces for these resolution settings) with a Z span that rests on the floor (<code>[0, 2 × bevel]</code>) and an X span of <code>2 × radius + 2 × bevel</code>.</p>
+<p>Staging: both ends of the semicircle face −Y, so the still looks from −Y and shows both filled caps (<code>use_fill_caps</code>, the witness) face-on, with the arc sweeping behind them. The old angle showed one cap and the other end edge-on. The cap&#x27;s 12-sided outline is the pinned tessellation (<code>bevel_resolution</code> 4, locked by the 1044-vertex gate), not a presentation choice.</p>
 <h2>Run</h2>
 <pre><code># Cheap correctness check (no render) — the CI check:
 blender --background --python curve_bevel_arc.py --
@@ -434,7 +435,9 @@ <h2>Source</h2>
     bsdf.inputs[<span class="s">&quot;Base Color&quot;</span>].default_value = (<span class="n">0.95</span>, <span class="n">0.10</span>, <span class="n">0.38</span>, <span class="n">1.0</span>)  <span class="c"># rose</span>
     bsdf.inputs[<span class="s">&quot;Roughness&quot;</span>].default_value = <span class="n">0.24</span>
     obj.data.materials.append(mat)
-    obj.rotation_euler = (<span class="n">0.0</span>, <span class="n">0.0</span>, math.radians(-<span class="n">18</span>))
+    <span class="c"># both capped ends face -Y with the arc unrotated, so the camera on -Y</span>
+    <span class="c"># sees the two caps (the witness) face-on and the arc sweeping behind</span>
+    obj.rotation_euler = (<span class="n">0.0</span>, <span class="n">0.0</span>, math.radians(-<span class="n">8</span>))
 
     floor_me = bpy.data.meshes.new(<span class="s">&quot;Floor&quot;</span>)
     bm = bmesh.new()
@@ -462,7 +465,7 @@ <h2>Source</h2>
     scene.world = world
 
     aim = bpy.data.objects.new(<span class="s">&quot;Aim&quot;</span>, <span class="k">None</span>)
-    aim.location = (<span class="n">0.0</span>, <span class="n">0.35</span>, BEVEL)
+    aim.location = (<span class="n">0.0</span>, <span class="n">0.55</span>, BEVEL)
     scene.collection.objects.link(aim)
 
     <span class="k">def</span> light(name, loc, energy, size, col):
@@ -494,7 +497,7 @@ <h2>Source</h2>
     cam_data = bpy.data.cameras.new(<span class="s">&quot;Cam&quot;</span>)
     cam_data.lens = <span class="n">50.0</span>
     cam = bpy.data.objects.new(<span class="s">&quot;Cam&quot;</span>, cam_data)
-    cam.location = (<span class="n">2.55</span>, -<span class="n">3.62</span>, <span class="n">1.78</span>)
+    cam.location = (<span class="n">1.1</span>, -<span class="n">4.3</span>, <span class="n">2.55</span>)
     scene.collection.objects.link(cam)
     scene.camera = cam
     track = cam.constraints.new(<span class="s">&#x27;TRACK_TO&#x27;</span>)
@@ -569,7 +572,7 @@ <h2>Source</h2>
   </main>
   <dialog class="lightbox" id="lightbox" aria-label="Full-size render">
     <button class="lightbox-close" type="button" autofocus>Close</button>
-    <img src="../assets/curve-bevel-arc-hero.webp" alt="A magenta beveled curve tube sweeping in an arc across a dark floor, with a capped end." />
+    <img src="../assets/curve-bevel-arc-hero.webp" alt="A magenta beveled curve tube lying in a semicircle on a dark floor, both filled end caps facing the camera." />
   </dialog>
   <footer>
     <div class="statusbar">

docs/gallery/index.html

@@ -475,7 +475,7 @@ <h2><a href="shape-key-blend/">shape-key-blend</a></h2>
       </article>
       <article class="card" data-tags="curves bevel">
         <a class="card-media" href="curve-bevel-arc/" tabindex="-1" aria-hidden="true">
-          <img src="assets/curve-bevel-arc-hero.webp" alt="A magenta beveled curve tube sweeping in an arc across a dark floor, with a capped end." loading="lazy" decoding="async" />
+          <img src="assets/curve-bevel-arc-hero.webp" alt="A magenta beveled curve tube lying in a semicircle on a dark floor, both filled end caps facing the camera." loading="lazy" decoding="async" />
         </a>
         <div class="card-body">
           <h2><a href="curve-bevel-arc/">curve-bevel-arc</a></h2>
@@ -717,7 +717,7 @@ <h2><a href="custom-normals-shade/">custom-normals-shade</a></h2>
       </article>
       <article class="card" data-tags="world sky rendering">
         <a class="card-media" href="sky-texture-sun-elevation/" tabindex="-1" aria-hidden="true">
-          <img src="assets/sky-texture-sun-elevation-hero.webp" alt="Split view of an orange cone under a procedural sky: sun elevation 8 degrees on the left, 55 degrees on the right." loading="lazy" decoding="async" />
+          <img src="assets/sky-texture-sun-elevation-hero.webp" alt="Split view of a pale glazed jar under a procedural sky: dim twilight blue at sun elevation 8 degrees on the left, bright daylight at 55 degrees on the right." loading="lazy" decoding="async" />
         </a>
         <div class="card-body">
           <h2><a href="sky-texture-sun-elevation/">sky-texture-sun-elevation</a></h2>
@@ -1036,12 +1036,12 @@ <h2><a href="park-bench/">park-bench</a></h2>
       </article>
       <article class="card" data-tags="mesh export showcase">
         <a class="card-media" href="wheelbarrow/" tabindex="-1" aria-hidden="true">
-          <img src="assets/wheelbarrow-hero.webp" alt="A wooden wheelbarrow with a box tray, spoked front wheel and two long handles." loading="lazy" decoding="async" />
+          <img src="assets/wheelbarrow-hero.webp" alt="A wooden wheelbarrow whose tray walls are stacked boards held by iron straps, with a spoked front wheel and two long handles." loading="lazy" decoding="async" />
         </a>
         <div class="card-body">
           <h2><a href="wheelbarrow/">wheelbarrow</a></h2>
           <p class="teaches">A procedural wooden wheelbarrow through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.</p>
-          <p class="witnesses"><span class="tag">witnesses</span> Recomputed: 2500 tris, two materials with 1094 wood and 190 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.556×0.630×0.572 m, zmin 0, hygiene 0, wall-floor seat 12 mm, spoke clearance 40 mm, LOD ratios in band (5.2 COLLAPSE leaner on LOD2), convex collider 90 tris, non-empty glTF. --skip-decimate exits 9 on LOD1; --stray-vert exits 15 on hygiene; --lift-z / --short-legs exit 16 on grounded; --fat-spokes / --float-walls exit 17 on joint fit; --pipe-rim exits 18 on tread aspect.</p>
+          <p class="witnesses"><span class="tag">witnesses</span> Recomputed: 2536 tris, two materials with 1157 wood and 190 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.556×0.630×0.572 m, zmin 0, hygiene 0, wall-floor seat 12 mm, spoke clearance 40 mm, two boards per side and front wall with 2 mm seams, LOD ratios in band (5.2 COLLAPSE leaner on LOD2), convex collider 90 tris, non-empty glTF. --skip-decimate exits 9 on LOD1; --stray-vert exits 15 on hygiene; --lift-z / --short-legs exit 16 on grounded; --fat-spokes / --float-walls / --wide-seams exit 17 on joint fit; --pipe-rim exits 18 on tread aspect.</p>
           <a class="card-link" href="wheelbarrow/">View showcase piece<span class="sr-only"> wheelbarrow</span> <span aria-hidden="true">&rarr;</span></a>
         </div>
       </article>
@@ -1168,12 +1168,12 @@ <h2><a href="iron-cauldron/">iron-cauldron</a></h2>
       </article>
       <article class="card" data-tags="mesh export showcase">
         <a class="card-media" href="wooden-ladder/" tabindex="-1" aria-hidden="true">
-          <img src="assets/wooden-ladder-hero.webp" alt="A wooden ladder with tapered stiles and round rungs, leaning at an angle." loading="lazy" decoding="async" />
+          <img src="assets/wooden-ladder-hero.webp" alt="A wooden ladder with tapered stiles and evenly spaced round rungs, leaning against a dark wall section." loading="lazy" decoding="async" />
         </a>
         <div class="card-body">
           <h2><a href="wooden-ladder/">wooden-ladder</a></h2>
           <p class="teaches">A procedural timber ladder with raked tapered stiles, six turned rungs, ferrule caps, and level shoe plates through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.</p>
-          <p class="witnesses"><span class="tag">witnesses</span> Recomputed: 2536 tris, two materials with 612 wood and 736 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.490×0.376×1.487 m, zmin 0, hygiene and coplanar pairs 0, tenon clearance 8 mm, shoe bite 20 mm, LOD ratios in band, convex collider 24 tris, non-empty glTF. --skip-decimate exits 9; --stray-vert and --twin-sole exit 15; --lift-z exits 16; --fat-rungs exits 17; --short-stile exits 18.</p>
+          <p class="witnesses"><span class="tag">witnesses</span> Recomputed: 2536 tris, two materials with 612 wood and 736 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.490×0.376×1.487 m, zmin 0, hygiene and coplanar pairs 0, tenon clearance 8 mm, shoe bite 20 mm, rung pitch even to 0.002 m, LOD ratios in band, convex collider 24 tris, non-empty glTF. --skip-decimate exits 9; --stray-vert and --twin-sole exit 15; --lift-z exits 16; --fat-rungs exits 17; --short-stile exits 18; --drift-rungs exits 19.</p>
           <a class="card-link" href="wooden-ladder/">View showcase piece<span class="sr-only"> wooden-ladder</span> <span aria-hidden="true">&rarr;</span></a>
         </div>
       </article>