@@ -169,7 +169,7 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show
   <a href="showcase/palm-tree/"><img src="showcase/palm-tree/preview.webp" width="24%" alt="Palm tree: a coconut palm leaning on a raised disc of beach sand, its ringed trunk curving up to a crown of drooping pinnate fronds over green coconuts, fallen coconuts, a frond and driftwood below" /></a>
   <a href="showcase/wingback-armchair/"><img src="showcase/wingback-armchair/preview.webp" width="24%" alt="Wingback armchair: an oxblood leather wingback with a deep-button tufted back, rolled arms trimmed with brass nailheads and a piped seat cushion, beside a side table with a brass reading lamp and books on a fringed rug" /></a>
   <a href="showcase/planet-rover/"><img src="showcase/planet-rover/preview.webp" width="24%" alt="Planet rover: a six-wheeled rocker-bogie rover with gold-foil sides, a camera mast, a dish antenna and a finned power unit, its arm drilling a boulder on red-grey regolith" /></a>
-  <a href="showcase/traffic-cones/"><img src="showcase/traffic-cones/preview.webp" width="24%" alt="Traffic cones: orange cones with white reflective collars on a patch of asphalt with a worn white line, three standing in a row, three nested in a stack and one knocked over showing its open base, before a striped A-frame barricade with an amber warning lamp" /></a>
+  <a href="showcase/traffic-cones/"><img src="showcase/traffic-cones/preview.webp" width="24%" alt="Traffic cones: scuffed orange cones with rub-marked white reflective collars on a patch of asphalt with a worn white line, three standing in a row, three nested in a stack and one knocked over showing its open base, before a striped A-frame barricade with an amber warning lamp" /></a>
   <a href="showcase/mushroom-stump/"><img src="showcase/mushroom-stump/preview.webp" width="24%" alt="Mushroom stump: a sawn tree stump with a stepped felling cut and torn hinge fibres, peeled bark with curling flakes, moss, banded shelf fungi, honey mushroom clusters, red fly agarics, ferns and fallen leaves on a sloping soil disc" /></a>
   <a href="showcase/go-kart/"><img src="showcase/go-kart/preview.webp" width="24%" alt="Go-kart: blue go-kart on a patch of track asphalt before a red and white kerb: moulded nose, side pods and a front panel with a white plate, red tube chassis, black seat, finned engine." /></a>
   <a href="showcase/broadleaf-oak/"><img src="showcase/broadleaf-oak/preview.webp" width="24%" alt="Broadleaf oak: a mature oak with a massive buttressed trunk and crooked limbs reaching out under a broad dome of lumpy dark-green leaf cushions, on a grassy mound with roots, tufts and fallen leaves" /></a>
 
@@ -1686,7 +1686,7 @@ <h2><a href="planet-rover/">planet-rover</a></h2>
       </article>
       <article class="card" data-tags="mesh export showcase" data-kind="showcase" data-category="vehicles" data-name="traffic-cones">
         <a class="card-media" href="traffic-cones/" tabindex="-1" aria-hidden="true">
-          <img src="assets/traffic-cones-hero.webp" alt="Orange cones on a patch of asphalt, three in a row, three stacked and one knocked over showing its open base, before a striped A-frame barricade with an amber lamp." width="1280" height="720" loading="lazy" decoding="async" />
+          <img src="assets/traffic-cones-hero.webp" alt="Scuffed orange cones on a patch of asphalt, three in a row, three stacked and one knocked over showing its open base, before a striped A-frame barricade with an amber lamp." width="1280" height="720" loading="lazy" decoding="async" />
         </a>
         <div class="card-body">
           <h2><a href="traffic-cones/">traffic-cones</a></h2>
 
@@ -856,7 +856,7 @@
       "dir": "showcase/traffic-cones",
       "category": "vehicles",
       "teaches": "A procedural roadworks set on a cut-out patch of asphalt — a broken-edged asphalt slab with a worn white road line and two sealed tar cracks; seven 720 mm PVC traffic cones, each a hollow lathed body with a moulded bead and a rolled lip round an open tip, bonded into a square rubber base with chamfered corners, a raked top, a collar, four moulded lugs and a recess underneath, and hooped with 4 in and 6 in retroreflective collars; three standing in a taper line, three nested in a stack whose wall thickness sets the nesting pitch, and one knocked over onto the edge of its base and the lip of its tip, its roll solved so both touch; a folding A-frame barricade of four square steel legs hinged in pairs on pivot bolts, spread by pinned straps on spacers, each foot in a rubber pad, carrying two boards on each face split on 45-degree lines into orange and white retroreflective stripes and bolted to the legs; and a warning lamp with amber fresnel lenses on a bracket bolted to the top board — through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.",
-      "alt": "Orange cones on a patch of asphalt, three in a row, three stacked and one knocked over showing its open base, before a striped A-frame barricade with an amber lamp.",
+      "alt": "Scuffed orange cones on a patch of asphalt, three in a row, three stacked and one knocked over showing its open base, before a striped A-frame barricade with an amber lamp.",
       "witnessesFix": "Recomputed: 45816 tris, eleven materials with 6048 cone PVC, 4088 reflective, 8096 rubber, 596 asphalt, 56 road paint, 496 tar, 64 orange sheeting, 384 board, 2912 steel, 720 black plastic and 696 lens faces, UVs in 0..1 with zero AABB overlap, outer AABB 3.037×2.037×1.335 m, zmin 0, hygiene 0 including zero coplanar cross-shell pairs, all 10 supports (five cone bases, the fallen cone's body and four barricade pads) 1.5 mm into the slab (band 0.8–3.0 mm), 4 boards biting their legs 1.5 mm at all 8 joints (band 0.8–3.0 mm), 14 collars seated 0.600 mm into their bodies and 1.400 mm proud, 6 upright cones 0.0000° off plumb at 0.720 m on bases 0.356 m across the flats, the barricade's 4 legs mirrored within 0.0001 mm, one stack of 3 at a 0.036 m pitch with each inner wall bearing 0.847–1.105 mm on the wall below (band 0.4–2.0 mm), one connected assembly of 125 shells, LOD ratios in band, collider 493 tris, non-empty glTF. --skip-decimate exits 9; --stray-vert 15; --lift-z 16; --float-cone 16; --gap-board 17; --float-band 18; --lean-cone 19; --skew-leg 19; --loose-stack 20; --loose-lamp 21.",
       "hero": "docs/gallery/assets/traffic-cones-hero.webp",
       "preview": "showcase/traffic-cones/preview.webp",
 
@@ -191,7 +191,10 @@ their boundaries are hard edges on a flat face and cannot z-fight. Every
 cone, board and leg carries a `PartTone` face attribute that the shaders
 read to move each part between two tones, so no two cones are the same
 orange. Grime rises from the slab on every part; scuffs are sparse and
-small. The steel is galvanised, grey and rough, with a studio reflection
+small. The cone PVC and its collars also carry level rub marks, black on
+the orange and grey on the sheeting: a noise squashed sixteen-fold in
+height, so each mark runs round the cone like a tyre or boot rub rather
+than up it. The steel is galvanised, grey and rough, with a studio reflection
 term so it does not read as plastic on a dark stage.
 
 ## Exit codes
 
@@ -1133,10 +1133,12 @@ def _gray(v):
 
 def weathered(name, col_a, col_b, rough, dirt_col, dirt_top, dirt_amt, scuff_col, scuff_amt,
               scuff_scale=38.0, metallic=0.0, rough_var=0.08, bump=0.0, bump_scale=600.0,
-              coat=0.0):
+              coat=0.0, rub=0.0, rub_col=(0.030, 0.027, 0.025, 1.0)):
     """A designed surface: a per-part tone between two colours (the PartTone
     face attribute), grime rising from the slab to ``dirt_top``, sparse
-    scuffs, roughness breakup and an optional fine bump."""
+    scuffs, ``rub``: level black tyre and boot rubs (a noise squashed flat,
+    so each mark runs round the part, not up it), roughness breakup and an
+    optional fine bump."""
     mat = bpy.data.materials.new(name)
     mat.use_nodes = True
     nt = mat.node_tree
@@ -1170,6 +1172,15 @@ def weathered(name, col_a, col_b, rough, dirt_col, dirt_top, dirt_amt, scuff_col
     sr = _ramp(nt, 0.60, _gray(0.0), 0.70, _gray(scuff_amt))
     nt.links.new(sn.outputs["Fac"], sr.inputs["Fac"])
     col = _mix(nt, sr.outputs["Color"], grime, scuff_col)
+    if rub > 0.0:
+        mp = nt.nodes.new("ShaderNodeMapping")
+        mp.inputs["Scale"].default_value = (1.0, 1.0, 16.0)
+        nt.links.new(coord.outputs["Object"], mp.inputs["Vector"])
+        rn = _node(nt, "ShaderNodeTexNoise", Scale=3.2, Detail=6.0, Roughness=0.62)
+        nt.links.new(mp.outputs["Vector"], rn.inputs["Vector"])
+        rk = _ramp(nt, 0.635, _gray(0.0), 0.700, _gray(rub))
+        nt.links.new(rn.outputs["Fac"], rk.inputs["Fac"])
+        col = _mix(nt, rk.outputs["Color"], col, rub_col)
     nt.links.new(col, bsdf.inputs["Base Color"])
     rr = _ramp(nt, 0.30, _gray(max(0.03, rough - rough_var)), 0.70,
                _gray(min(0.95, rough + rough_var)))
@@ -1342,10 +1353,11 @@ def set_materials():
     plastic, amber lens. Shared by the check and the render."""
     cone = weathered("ConePVC", (0.90, 0.19, 0.012, 1.0), (0.74, 0.20, 0.040, 1.0), 0.46,
                      (0.13, 0.085, 0.050, 1.0), 0.26, 0.85, (0.30, 0.10, 0.04, 1.0), 0.55,
-                     scuff_scale=26.0, coat=0.15)
+                     scuff_scale=26.0, coat=0.15, rub=0.92)
     reflect = weathered("ReflectiveWhite", (0.78, 0.78, 0.76, 1.0), (0.66, 0.66, 0.63, 1.0), 0.30,
                         (0.36, 0.32, 0.26, 1.0), 0.40, 0.60, (0.50, 0.50, 0.49, 1.0), 0.65,
-                        scuff_scale=70.0, bump=0.12, bump_scale=900.0)
+                        scuff_scale=70.0, bump=0.12, bump_scale=900.0, rub=0.6,
+                        rub_col=(0.10, 0.095, 0.088, 1.0))
     rubber = weathered("RubberBase", (0.036, 0.035, 0.034, 1.0), (0.050, 0.048, 0.045, 1.0), 0.78,
                        (0.17, 0.155, 0.14, 1.0), 0.03, 0.55, (0.10, 0.098, 0.095, 1.0), 0.8,
                        scuff_scale=20.0, bump=0.25, bump_scale=400.0)