Market Stall

A showcase piece, not an example. Procedural timber stall (corner posts with wrap plinths, slatted counter and shelf, back-wall planks, side braces that run post to post, striped awning with a front roller and hanging valance) then the shipped pipeline: unique-cell UVs, Cycles high-to-low normal bake, LOD chain, convex collider, Unity glTF export.

The old piece used capped foot cubes coplanar with the post bottoms and counter-leg pads coplanar with the legs, which z-fought at Z=0. Wrap plates stand off the post; counter legs go to Z=0 without a second bottom face.

The side braces used to start at the back post and stop at mid-depth, 0.43 m short of the front post, nearly level and joined to nothing at the front: in the side elevation they read as pegs hanging in the air. The audit that should have caught it never did, because a level brace fails its brace shape test and was never measured. Each brace now runs from the front post, just above the counter, up to the back post under the header, so the side bay is triangulated; the brace-in-post seat below asserts both ends. Wood carries grain and a tone per piece (PlankTone / GrainDir face attributes), and the awning is a matte canvas with faint dirt, not two flat paints.

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, 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, not imported as a package).

Budgets#

Declared as named constants; every gate recomputes from the mesh, materials, UVs, evaluated LOD, collider, or export file.

Hygiene#

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

Joint fit and seat#

DECIMATE COLLAPSE triangle counts are not identical across series — the gate is a ratio band, not an exact count. Bake pixels are stochastic; the gate is has_data plus operator FINISHED, not byte-identity. Construction uses no RNG; the per-piece wood tone is drawn from a seeded random.Random(TONE_SEED), the same every run. Export byte counts differ by series (glTF serializer), not a gated axis.

Falsifiers#

Each violates one named budget. Every falsifier was run on 4.5.11, 5.1.2 and 5.2.1 and returned the same code on each.

Run#

blender --background --python market_stall.py --
blender --background --python market_stall.py -- --skip-decimate
blender --background --python market_stall.py -- --stray-vert
blender --background --python market_stall.py -- --lift-z
blender --background --python market_stall.py -- --short-feet
blender --background --python market_stall.py -- --low-brace
blender --background --python market_stall.py -- --short-brace
blender --background --python market_stall.py -- --float-awning
blender --background --python market_stall.py -- --rake-posts
blender --background --python market_stall.py -- --output stall.png

Smoke passes no flags.

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.