feat(examples): add solidify-even-thickness and boolean-exact-volume (#305)

solidify-even-thickness: a strip folded at 60, 90 and 120 degrees,
solidified in Simple mode (offset -1, t = 0.16).
- Without use_even_offset, each fold vertex's copy moves t along the
  bisector of its face normals, so the shell is t*cos(phi/2) thick:
  0.1386, 0.1131 and 0.0800.
- With use_even_offset, the copy moves t/cos(phi/2) and the shell is
  exactly t thick.
- Both closed forms are derived from the profile geometry and match to
  3.7e-8. Exits: 4 even shell, 5 plain-shell closed form, 6 thinning
  floor.
- --no-even exits 4 (0.0800 against 0.1600).
- The ROADMAP candidate's "1/cos(theta/2)" was imprecise; the shipped line
  states the cos(phi/2) factor on the bend angle.

boolean-exact-volume: the Boolean modifier's EXACT solver on a 2 m cube
and a 2x1x1 m slab whose top face is coplanar with the cube's top. Both
operands are translated and turned 18 degrees about Z.
- Union, difference and intersection measure 9, 7 and 1 m^3 by the
  divergence theorem, to 1e-6 relative (exit 3).
- Each result is a closed 2-manifold with no loose geometry (exit 4).
- --float-solver exits 3 with a 7.708 m^3 union.
- The floating-point solver is named 'FAST' on 4.5 and 'FLOAT' on 5.x,
  so the script branches on bpy.app.version.

Both default runs exit 0 on Blender 4.5.11, 5.1.2 and 5.2.1. Both
falsifiers are proven on 4.5.11 and 5.2.1 (boolean's also on 5.1.2).
tests/smoke/run_example.py reports [PASS] for both on 5.2.1 and 4.5.11.
Contact sheets are committed; every criterion passes for both.

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

Author: TMHSDigital

.cursor-plugin/plugin.json

@@ -138,7 +138,9 @@
     "examples/vse-linear-modifiers",
     "examples/wave-displace",
     "examples/ray-cast-space",
-    "examples/lattice-deform"
+    "examples/lattice-deform",
+    "examples/solidify-even-thickness",
+    "examples/boolean-exact-volume"
   ],
   "showcase": [
     "showcase/shipping-crate",

AGENTS.md

@@ -20,7 +20,7 @@ a `.cursor-plugin/plugin.json` manifest so the ecosystem drift checker
 classifies it as a `cursor-plugin`. This is content the AI loads when the user
 asks Blender questions or works on Blender add-ons in Cursor or Claude Code.
 
-The content base is 16 skills, 9 rules, 3 templates, 27 snippets, 62
+The content base is 16 skills, 9 rules, 3 templates, 27 snippets, 64
 examples, and 74 showcase pieces (counts are CI-enforced against README.md)
 and the manifest). The full inventory tables and per-item purposes live in
 `CLAUDE.md`. Example anatomy and authoring rules: copy `examples/bmesh-gear/`;
@@ -36,7 +36,7 @@ Blender-Developer-Tools/
   rules/<rule-name>.mdc          # 9 rule files
   templates/<template-name>/     # 3 starter templates
   snippets/<snippet-name>.py     # 27 standalone Python snippets
-  examples/<name>/               # 62 runnable smoke-gated examples (+ gallery.json)
+  examples/<name>/               # 64 runnable smoke-gated examples (+ gallery.json)
   examples/gallery_framing.py    # shared Layer 1 framing measurement (render path only)
   showcase/<name>/               # budget-conformance props (sibling of examples/)
   showcase/gallery.json          # this tree's gallery index; merged into docs/gallery/

CLAUDE.md

@@ -21,7 +21,7 @@ skills/<skill-name>/SKILL.md   - AI workflow definitions, 16 total
 rules/<rule-name>.mdc          - Anti-pattern rules, 9 total
 templates/<template-name>/     - Starter projects, 3 total
 snippets/<snippet-name>.py     - Standalone code patterns, 27 total
-examples/<name>/               - Runnable smoke-gated examples, 62 total (+ gallery.json)
+examples/<name>/               - Runnable smoke-gated examples, 64 total (+ gallery.json)
 showcase/<name>/               - Budget-conformance props, 74 pieces, each with a gallery `category` (sibling of examples/; see showcase/README.md § Categories)
 scripts/build_gallery.py       - Regenerates docs/gallery/ from examples/gallery.json + showcase/gallery.json
 scripts/site/                  - Vendored landing-page build (Jinja2); tokens.css is the shared palette
@@ -105,12 +105,12 @@ v0.2.0: Principled BSDF material, driver-with-custom-function via `driver_namesp
 
 AI asset pipeline track: `decimate_to_budget.py`, `convex_hull_collider.py`, `lod_chain.py` (helper duplicated, not imported), `gltf_draco_export.py`, `export_preset_unity.py`, `export_preset_godot.py`, `export_preset_unreal.py`, `setup_bake_target_image.py`, `bake_normal_high_to_low.py`, `save_baked_image.py`.
 
-## Examples (62)
+## Examples (64)
 
 Runnable scripts at `examples/<name>/`, each asserting a real API contract with
 deterministic checks (exit non-zero on failure) and optionally rendering a still via
 `--output`. All of them run headless on Blender 5.2 LTS and 4.5 LTS in `blender-smoke.yml` (5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch);
-**54 of the 62 ship a render in the site gallery** at `docs/gallery/`. The other
+**56 of the 64 ship a render in the site gallery** at `docs/gallery/`. The other
 eight are **check-only**: they carry no `--output` path, no gallery entry, and no
 hero asset. The criterion is whether the contract is expressible in pixels. An
 example is check-only when its witness is a data or state fact that no scene

README.md

@@ -18,7 +18,7 @@
 </p>
 
 <p align="center">
-  <strong>16 skills</strong> &nbsp;&bull;&nbsp; <strong>9 rules</strong> &nbsp;&bull;&nbsp; <strong>3 templates</strong> &nbsp;&bull;&nbsp; <strong>27 snippets</strong> &nbsp;&bull;&nbsp; <strong>62 examples</strong> &nbsp;&bull;&nbsp; <strong>74 showcase pieces</strong>
+  <strong>16 skills</strong> &nbsp;&bull;&nbsp; <strong>9 rules</strong> &nbsp;&bull;&nbsp; <strong>3 templates</strong> &nbsp;&bull;&nbsp; <strong>27 snippets</strong> &nbsp;&bull;&nbsp; <strong>64 examples</strong> &nbsp;&bull;&nbsp; <strong>74 showcase pieces</strong>
 </p>
 
 <p align="center">
@@ -37,7 +37,7 @@
 
 ## Overview
 
-This repository ships **16 skills, 9 rules, 3 templates, 27 snippets, 62 examples, and 74 showcase pieces** for Blender Python development targeting Blender 5.2 LTS (current stable) with Blender 4.5 LTS fallback support. Blender 5.1 is prior stable.
+This repository ships **16 skills, 9 rules, 3 templates, 27 snippets, 64 examples, and 74 showcase pieces** for Blender Python development targeting Blender 5.2 LTS (current stable) with Blender 4.5 LTS fallback support. Blender 5.1 is prior stable.
 
 The content is consumed by AI coding agents reading these files directly from a checkout — **there is no MCP server in this repository, and none is required**. Cursor applies `rules/*.mdc` automatically wherever their scope globs match and takes skills by name in chat; Claude Code reads `skills/` and `rules/` from the project workspace, or from this repo kept as a referenced checkout. Any agent that can read files in a workspace can use it the same way. There is no build step for the content — edit the Markdown and Python files directly.
 
@@ -75,7 +75,7 @@ blender --background --python examples/bmesh-gear/bmesh_gear.py --
 
 ## Falsifiers
 
-Every one of the 62 examples carries a **falsifier**: a flag that changes the
+Every one of the 64 examples carries a **falsifier**: a flag that changes the
 input so a real assertion fails. It never disables the assertion, skips the
 check, or short-circuits to an error — it feeds the script something the
 contract says must not pass, and the same check that guards the happy path
@@ -458,7 +458,7 @@ Gallery still is a sky-lit obelisk diptych (8° dusk | 55° midday) so the contr
 </details>
 
 <details>
-<summary><strong>Mesh, curves &amp; text</strong> — 15 examples</summary>
+<summary><strong>Mesh, curves &amp; text</strong> — 17 examples</summary>
 
 <table>
 <tr>
@@ -686,6 +686,36 @@ A 2×2×2 Lattice modifier set to `'KEY_LINEAR'`, with two corners moved through
 blend of the eight deformed corners, and that the default `'KEY_BSPLINE'` misses it
 (`--bspline` exits 4).
 
+</td>
+</tr>
+<tr>
+<td width="46%" valign="middle">
+<a href="examples/solidify-even-thickness/"><img src="examples/solidify-even-thickness/preview.webp" alt="Solidify even thickness: two folded zigzag shells on a walnut plinth, their cut ends in orange, the left band pinching thin at every fold and the right staying one width, above brass plaques reading use_even_offset = False and use_even_offset = True" /></a>
+</td>
+<td valign="middle">
+
+### [solidify-even-thickness](examples/solidify-even-thickness/)
+
+Solidify on a strip folded at 60°, 90° and 120°. Without `use_even_offset`, each fold vertex
+moves *t* along the bisector and the wall thins to *t*·cos(φ/2), half at 120°. With it, the
+vertex moves *t*/cos(φ/2) and the wall stays exactly *t*. Both closed forms are measured off
+the evaluated mesh to 1e-5 (`--no-even` exits 4).
+
+</td>
+</tr>
+<tr>
+<td width="46%" valign="middle">
+<a href="examples/boolean-exact-volume/"><img src="examples/boolean-exact-volume/preview.webp" alt="Boolean exact volume: three results on a walnut plinth, each inside thin steel and glowing orange outlines of its two operands - a teal union with a slab grown out of a cube, a brass cube with a notch cut down through its top, and the orange one-metre overlap cube, on a dark studio floor" /></a>
+</td>
+<td valign="middle">
+
+### [boolean-exact-volume](examples/boolean-exact-volume/)
+
+The Boolean modifier on `solver='EXACT'`, cutting a cube with a slab whose top face is
+coplanar with the cube's. Union, difference and intersection measure their closed-form
+9, 7 and 1 m³ by the divergence theorem and are closed 2-manifolds. The floating-point
+solver, renamed `'FAST'` → `'FLOAT'` in 5.0, gets the union wrong (`--float-solver` exits 3).
+
 </td>
 </tr>
 </table>

ROADMAP.md

@@ -167,8 +167,9 @@ Not committed; target list for the next content version. (v0.3.0 shipped the smo
 - `mathutils.bvhtree` witness — `BVHTree.FromObject` on evaluated geometry: `find_nearest` distances and `overlap` pairs match closed forms on a known arrangement
 - Curves datablock witness — the modern `bpy.types.Curves` hair API (`add_curves`, `position` attribute, `curve_offset_data`) vs legacy particle hair: point and curve counts closed-form, every root on the emitter surface
 - Non-Color normal-map witness — an image used as a normal map must be `colorspace_settings.name = 'Non-Color'`; a baked/sampled value round-trips only then, and sRGB shifts it by the transfer curve (a silent shading error AI code ships)
-- Solidify even-thickness witness — `use_even_offset` keeps shell thickness constant at sharp corners, while without it the corner thins by 1/cos(θ/2): measured thickness at a known angle matches both closed forms
-- Boolean solver witness — EXACT solver union/difference volumes match closed forms on overlapping primitives, and the result is manifold; FAST on coplanar faces is the documented failure case
+- ~~Solidify even-thickness witness — `use_even_offset` keeps shell thickness constant at sharp corners, while without it the corner thins by 1/cos(θ/2): measured thickness at a known angle matches both closed forms~~ **SHIPPED** as `examples/solidify-even-thickness/` — Simple-mode Solidify (offset −1) on a strip folded at 60°/90°/120°: the even shell is exactly t thick (copies t/cos(φ/2) along the bisector), the plain shell t·cos(φ/2) = t·sin(θ/2) (0.866t, 0.707t, 0.5t), both to 3.7e-8; the candidate's "thins by 1/cos(θ/2)" was imprecise, since the factor is cos(φ/2) on the bend angle; `--no-even` exits 4
+- ~~Boolean solver witness — EXACT solver union/difference volumes match closed forms on overlapping primitives, and the result is manifold; FAST on coplanar faces is the documented failure case~~ **SHIPPED** as `examples/boolean-exact-volume/` — union/difference/intersection of a cube and a top-coplanar slab through translated, Z-turned operands: 9 / 7 / 1 m³ by the divergence theorem (1e-6 rel), closed 2-manifolds; the floating-point solver (`'FAST'` on 4.5, renamed `'FLOAT'` in 5.0) gives a 7.708 m³ union and `--float-solver` exits 3
+- MANIFOLD Boolean solver witness — the 4.5+ `'MANIFOLD'` solver against EXACT on the same closed-form operands: identical volumes with fewer faces (10 vs 14 on the fully coplanar union), plus its documented refusal of non-manifold input operands (result empty or unchanged) as the falsifier
 - ~~Lattice deform witness — a 2×2×2 lattice with one displaced point deforms interior verts by exact trilinear weights (`interpolation_type_u/v/w = 'KEY_LINEAR'`)~~ **SHIPPED** as `examples/lattice-deform/` — 602 evaluated verts on the trilinear closed form (5.6e-7) through a translated, non-uniformly scaled lattice; `--bspline` (the default interpolation) exits 4 at 0.2145
 - Lattice `use_outside` / outside-vertex witness — verts outside a KEY_LINEAR lattice's volume: assert the documented clamp or extrapolation closed form, and `use_outside` (deform only the outer points) against an interior-only control move
 - FBX unit-scale witness — `export_scene.fbx` with `apply_unit_scale` / `apply_scale_options` changes exported coordinates by the closed-form ×100 cm factor; re-import restores metres only on the matching option

docs/gallery/armature-bend/index.html

@@ -45,7 +45,7 @@ <h1>Armature Bend</h1>
     <p>Rigging end to end in the data API — edit_bones chain construction, name-bound vertex groups with smoothstep blend zones, posing, and depsgraph evaluation — bending a ribbed bellows hose through rest, half, and full curl.</p>
   </header>
   <main id="main">
-    <nav class="pager" aria-label="Examples"><a rel="prev" href="../grease-pencil-rosette/" aria-label="Previous example: grease-pencil-rosette"><span aria-hidden="true">&larr;</span> grease-pencil-rosette</a><span class="pager-pos hud">19 of 54 examples<span class="pager-keys"> &middot; <kbd>&larr;</kbd><kbd>&rarr;</kbd></span></span><a rel="next" href="../text-version-stamp/" aria-label="Next example: text-version-stamp">text-version-stamp <span aria-hidden="true">&rarr;</span></a></nav>
+    <nav class="pager" aria-label="Examples"><a rel="prev" href="../grease-pencil-rosette/" aria-label="Previous example: grease-pencil-rosette"><span aria-hidden="true">&larr;</span> grease-pencil-rosette</a><span class="pager-pos hud">19 of 56 examples<span class="pager-keys"> &middot; <kbd>&larr;</kbd><kbd>&rarr;</kbd></span></span><a rel="next" href="../text-version-stamp/" aria-label="Next example: text-version-stamp">text-version-stamp <span aria-hidden="true">&rarr;</span></a></nav>
     <button class="detail-hero" id="heroZoom" type="button" aria-label="View full size: Three ribbed bellows hoses with brass collars on steel foot flanges, banded teal to amber to coral, standing straight, half curled and fully curled by an armature.">
       <img src="../assets/armature-bend-hero.webp" alt="Three ribbed bellows hoses with brass collars on steel foot flanges, banded teal to amber to coral, standing straight, half curled and fully curled by an armature." width="1280" height="720" fetchpriority="high" />
     </button>
@@ -1050,7 +1050,7 @@ <h3><a class="stretch" href="../lod-decimate-chain/">LOD Decimate Chain</a></h3>
         </article>
       </div>
     </section>
-    <nav class="pager pager-foot" aria-label="Examples"><a rel="prev" href="../grease-pencil-rosette/" aria-label="Previous example: grease-pencil-rosette"><span aria-hidden="true">&larr;</span> grease-pencil-rosette</a><span class="pager-pos hud">19 of 54 examples</span><a rel="next" href="../text-version-stamp/" aria-label="Next example: text-version-stamp">text-version-stamp <span aria-hidden="true">&rarr;</span></a></nav>
+    <nav class="pager pager-foot" aria-label="Examples"><a rel="prev" href="../grease-pencil-rosette/" aria-label="Previous example: grease-pencil-rosette"><span aria-hidden="true">&larr;</span> grease-pencil-rosette</a><span class="pager-pos hud">19 of 56 examples</span><a rel="next" href="../text-version-stamp/" aria-label="Next example: text-version-stamp">text-version-stamp <span aria-hidden="true">&rarr;</span></a></nav>
   </main>
   <dialog class="lightbox" id="lightbox" aria-label="Full-size render">
     <div class="lightbox-bar"><button class="lightbox-close" id="lightboxNative" type="button" aria-pressed="false">Actual size</button><button class="lightbox-close" id="lightboxClose" type="button" autofocus>Close</button></div>