espresso-machine

Espresso machine

A showcase piece, not an example, and the fifth in the household category. It builds a procedural prosumer E61 semi-automatic espresso machine, generic and unbranded, on a short countertop section:

• a honed limestone countertop section 0.67 × 0.655 m with a bullnose front edge and eased cut ends;
• a black painted chassis box behind a brushed stainless front panel, a back panel, and two side panels folded round the front and back edges, each a single sheet with two banks of seven louvred vent slots cut through it;
• four adjustable feet: a rubber pad on the counter, a chrome stem up into the chassis and a hex lock nut;
• a pressed stainless warmer tray on top with a tubular rail bent from one bar (down into the tray at the front, round the sides and back) and two rear posts, carrying three upturned demitasses and a cappuccino cup;
• the E61 group: a cast neck and a thermosiphon pipe off the panel, a skirted bayonet ring with a rubber gasket in its bore, a waisted body under the mushroom cap, a chimney on top with two lug posts and bosses, and the lever's hub on a domed pin through them, its arm ending in a bakelite ball;
• a spouted portafilter locked into the group against the gasket: a chrome body with two bayonet ears, a shank into a turned walnut handle, a spout block and two spouts;
• steam (right) and hot-water (left) valves with fluted bakelite knobs and chrome caps, each wand hung from a ball joint under its valve and ending in a nozzle;
• twin pressure gauges side by side above the group: chrome bezels, dials printed with tick marks (every fourth one long) and a red band, needles on hubs, and domed glasses sat back inside the bezels' lips;
• a power toggle and an amber pilot lamp;
• a pressed drip tray tucked under the front panel, its grate one sheet with 31 slots cut through it, a shot cup of espresso on the grate under the spouts; and
• on the counter: a stainless knock box on a rubber base ring with a rubber bar across its rim and two spent pucks inside, a tamper with a walnut handle, and a milk pitcher with a pulled spout and a strap handle.

Every face carries a part tag (a face attribute written as each part is built), and the audits classify shells by it. The measurements themselves are read off the mesh.

The side panels and the grate are one helper, add_sheet: a sheet swept along a plan path through a set of heights, where each cell of that grid is metal or a slot, and every slot is walled round. Each is a single manifold shell of quads. A side panel's path runs in from the front fold, round a 4 mm bend, down the side past the vent banks' stations, round the back bend and in again, so the folds and the louvres are one piece of metal, as they are on the machine.

Stainless and chrome carry a studio in their material. A metal on the house's dark stage mirrors the dark stage and reads as grey paint (the stand mixer's bowl did). Here the world-space reflection vector looks up a ramp — a bright band of walls and softboxes around the horizon, a dim ceiling, a dark floor straight down, the key's side brighter than the other — added as emission, so the metal reads in the hero and on the asset sheet's neutral stage alike. A vertical panel seen from above mirrors what lies just below the horizon: the first ramp, bright only above it, left every panel black. Steel gets a soft gradient down a panel; chrome a narrow bright horizon, a dark gap and a softbox above.

Things the coplanar budget forced:

• The feet's stem caps sat on the drip tray's floor plane; the stems tuck a millimetre further into the chassis.
• The two lug posts are mirror images, so their chamfers shared planes. One is staggered 0.8 mm in y and 0.3 mm in z. Staggering both axes by similar amounts cancelled on the 45° chamfers and fixed nothing.
• The gauge glass had the dial's radius, so the two rims met on a plane wherever their facets lined up; the glass is 0.3 mm larger.
• Side by side, the two gauges' dials and bezels shared every plane facing the camera (26026 pairs); the right gauge sits 0.4 mm prouder.
• --bunch-feet packs two pads 47 mm apart, where their near-flat top rings met on one plane. The pad top is now a steep chamfer.
• --narrow-body put a valve flange into the side panel's bend, where a flange facet and a bend facet met on one plane. The narrow body is 1.5 mm wider, so the flange clears the bend.

Shading follows what each part is. Lathed parts, sweeps and cups are smooth-shaded; chamfers, slots, knurls and folds stay crisp above 35° and at every material boundary. The walnut is oiled (a thin coat) with its grain noise stretched along one axis; the porcelain carries a glaze coat.

It asserts budget conformance of the generated result. It does not witness an API contract. "It rendered without error" is not a check.

Composes skills mesh-editing-and-bmesh, bake-high-to-low, depsgraph-and-evaluated-data, engine-export-presets, procedural-materials-and-shaders, and snippets bake_normal_high_to_low.py, setup_bake_target_image.py, lod_chain.py / decimate_to_budget.py, convex_hull_collider.py, export_preset_unity.py (helpers copied inline, not imported).

Intended size: a machine 0.300 m wide and 0.391 m to its warmer tray on a 0.03 m counter, 0.376 m deep plus a 0.12 m drip tray, with a 0.064 m cappuccino cup setting the top. The outer AABB is 0.670 × 0.655 × 0.4755 m: the counter sets the plan and the cup the top. The origin is under the counter.

Budgets

Every budget is declared as a named constant. Every gate recomputes its value from the mesh, materials, UVs, evaluated LOD, collider, or export file.

Axis	Declared	Measured (5.2.1)
Base triangles	43000–44300	43636
LOD1 ratio	0.32–0.62 of base	0.5000
LOD2 ratio	0.10–0.35 of base	0.2200
Materials	exactly 14 distinct; face floors ≥4400 stainless, ≥6700 chrome, ≥870 bakelite, ≥580 wood, ≥5330 ceramic, ≥1140 rubber, ≥580 glass, ≥1510 dial, ≥58 ink, ≥32 needle, ≥84 stone, ≥24 paint, ≥415 coffee, ≥106 lamp	14 slots; 4788 / 7284 / 948 / 632 / 5800 / 1244 / 632 / 1642 / 64 / 36 / 91 / 26 / 452 / 116
UVs	in 0..1, AABB overlap ≤ 1e-5	in range, overlap 0
Outer AABB	(0.670, 0.655, 0.4755) m ± 0.01	(0.6700, 0.6550, 0.4755), zmin 0
Collider tris	≤ 520	346
Export	written, size > 0, removed after measuring	3222244 / 3222244 / 3222236 bytes (4.5.11 / 5.1.2 / 5.2.1)

No falsifier changes the topology, so every one of them measures the default's 43636 triangles. Every one keeps the default's AABB except --sink-cup, which sinks the cup that sets the top 3 mm and measures 0.4725 m, inside the 10 mm tolerance.

DECIMATE COLLAPSE triangle counts are not identical across Blender series, so the LOD gate is a ratio band, not an exact count. Bake pixels are stochastic, so the bake gate is has_data plus operator FINISHED, not byte-identity. Construction uses no RNG; two default runs print identical measurements.

Hygiene

Recomputed from the generated mesh, not asserted about the script.

Axis	Declared	Measured
Non-manifold edges	0	0
Loose verts / edges	0 / 0	0 / 0
Doubles merged at 1e-5	0	0
Zero-area faces	0	0
N-gons	0	0
Coplanar cross-shell face pairs (KD range 0.05 m, plane ε 1e-4)	0	0
Grounded: zmin	within 1e-4 of 0	0.0000
Feet: each of the 4 rubber pads sunk into the counter top read off the mesh	0.0001–0.0008 m	0.00025, 0.00040, 0.00055, 0.00070

Lever, cups, size, portafilter, gauges, tray, stance and assembly

Axis	Declared	Measured
Lever pin: the pin's PCA axis against the axis of each of the 2 bosses and the lever's hub; the pin spans each in x; tilt off X	≤ 0.0003 m; 2 + 1; 0 not through; ≤ 0.5°	0.000000; 2 + 1; 0; 0.0000°
Cups seated: each of the 5 cups' lowest ring against its host's top, read by rays down onto the host alone (the warmer tray for the four upturned cups, the grate for the shot cup)	0.0001–0.0009 m	0.00020, 0.00038, 0.00056, 0.00074; 0.00035
Size: width across the side panels; warmer-tray top above the counter	0.300 ± 0.004 m; 0.3907 ± 0.004 m	0.30000; 0.39070
Portafilter coaxial: the portafilter body's and the gasket's axes (lathe centroids) against the group's	≤ 0.0003 m	0.000000; 0.000000
Portafilter seat: the basket rim's top pressed into the gasket's face	0.0001–0.0008 m	0.00040
Gauge faces: each glass's front behind its bezel's front lip	0.0015–0.0050 m; 2 + 2	0.0034, 0.0034
Drip tray: inside the side panels on both sides; its back tucked behind the front panel's face	margin ≥ 0.010 m; tuck ≥ 0.005 m	0.0250; 0.0170
Stance: mass centre (shell volumes × densities, counter and props excluded) inside the convex polygon of the pads' contact faces	≥ 0.060 m	0.1064 (39.83 kg)
One connected assembly (union of shells whose BVH trees overlap; faceless shells are hygiene's)	1 component	1 (94 shells)

A heat-exchanger E61 carries its group, portafilter and drip tray well in front of the chassis, and stands because its feet are spread under it. The stance budget measures that. The densities are named constants (stainless and paint steel 7900/7800, chrome-plated brass 8500, bakelite 1400, walnut 700, porcelain 2300, rubber 1200, glass 2500), with the chassis box overridden at 350: it is solid in the mesh, a frame round a boiler and air in the machine.

Falsifiers

Each falsifier violates one named budget. Every one was run on 5.2.1 and exited its declared code, and every other budget in its run stayed green.

Flag	Budget violated	Exit
--skip-decimate	LOD1 ratio band (measured 1.0000)	9
--stray-vert	loose vertex count is 0 (measured 1, placed inside the envelope)	15
--lift-z	bounding box zmin is 0 (measured 0.05000)	16
--float-foot	feet on the counter (one pad 3 mm up: seat −0.00230 m)	16
--offset-pin	lever pin coaxial through its bosses and hub (pin 1.5 mm up: 0.001500 m)	17
--sink-cup	cups seated on their host (the cappuccino cup 3 mm into the tray: 0.00356 m)	18
--narrow-body	size (side panels drawn in: width 0.28300 m)	19
--offset-pf	portafilter coaxial with the group (slid 1.2 mm: 0.001200 m)	20
--drop-pf	portafilter seated to the gasket (2 mm low: seat −0.00160 m)	21
--proud-gauge	gauge faces behind their bezels (glass, dial and needle 4.5 mm out: recess −0.0011 m)	22
--shift-tray	drip tray inside the body's footprint (30 mm right: margin −0.0050 m)	23
--bunch-feet	stance (feet under the back: margin −0.1613 m)	24
--loose-knob	one connected assembly (steam knob 5 mm off its valve: 2 components)	25

--float-foot leaves the pad's stem still inside it, so the assembly holds. --drop-pf and --offset-pf leave the portafilter inside the group's skirt, so it stays joined and only the seat or the axis moves. --sink-cup sinks, rather than floats, the cup, so the cup stays joined to the tray. --proud-gauge leaves the glass and dial inside the bezel's bore. --shift-tray keeps the tray tucked into the chassis, and the shot cup on the grate. --bunch-feet keeps every pad on the counter and under the chassis, so only the mass centre leaves the support polygon.

Run

blender --background --python espresso_machine.py --
blender --background --python espresso_machine.py -- --skip-decimate
blender --background --python espresso_machine.py -- --stray-vert
blender --background --python espresso_machine.py -- --lift-z
blender --background --python espresso_machine.py -- --float-foot
blender --background --python espresso_machine.py -- --offset-pin
blender --background --python espresso_machine.py -- --sink-cup
blender --background --python espresso_machine.py -- --narrow-body
blender --background --python espresso_machine.py -- --offset-pf
blender --background --python espresso_machine.py -- --drop-pf
blender --background --python espresso_machine.py -- --proud-gauge
blender --background --python espresso_machine.py -- --shift-tray
blender --background --python espresso_machine.py -- --bunch-feet
blender --background --python espresso_machine.py -- --loose-knob
blender --background --python espresso_machine.py -- --output espresso.png

Smoke passes no flags.

The camera looks along (−0.55, 0.83), so the hero shows the machine's front — gauges, knobs, group, portafilter handle in profile, shot cup on the grate — and its right side panel with the vent banks, with the tamper and pitcher in the left foreground and the knock box to the right. The wall behind the machine in frame lies 1.6 m to its −X, so the warm wedge is aimed there rather than at the wall straight behind the piece.

Exit codes

File-local. 9 is a valid check code. 10 is reserved for gallery_framing.check_framing on the --output path. 15–19 are the hygiene and joint-fit family. 20–25 are file-local. 26 is the asset-quality floor on the render path: check_asset_quality returns 11, which this piece already spends on the collider ceiling, so the call site remaps it.

Code	Meaning
0	Success
1	Uncaught exception (FATAL wrapper)
2	argparse / usage
3	Mesh did not build / no UV layer
4	Base triangle count outside range
5	Material count ≠ 14 distinct slots, or a face-count floor missed
6	UVs outside 0..1
7	UV AABB overlap above tolerance
8	World AABB off declared outer size
9	LOD ratio band (--skip-decimate lands here)
10	Framing gate (render path only)
11	Collider triangle count above ceiling
12	Bake did not finish or image has no data
13	Export file missing or empty
14	--output produced no file
15	Mesh hygiene: loose, non-manifold, zero-area, doubles, n-gons, coplanar cross-shell pairs
16	Not grounded: bounding box zmin off 0, or a pad off the counter or not 4 pads (--lift-z, --float-foot)
17	Lever pin off a boss's or the hub's axis, not spanning one, tilted, or not 2 + 1 (--offset-pin)
18	A cup's seat on its host outside its band, or not 5 cups (--sink-cup)
19	Size: body width or warmer-tray height off (--narrow-body)
20	Portafilter or gasket off the group's axis (--offset-pf)
21	Portafilter rim's seat in the gasket outside its band (--drop-pf)
22	A gauge glass not recessed in its bezel by the band, or not 2 + 2 (--proud-gauge)
23	Drip tray outside the side panels' margin or not tucked behind the front panel (--shift-tray)
24	Stance: mass centre within 60 mm of the pads' support polygon's edge (--bunch-feet)
25	Assembly splits into more than one connected component (--loose-knob)
26	Asset-quality floor (render path only; remapped from 11)