The piece the kit had been assembled around without having. The basket, the
vegetables, the sack, the crate and the coin pouch all belong on one, and a
market with none of it is a row of props on a floor. It is also the only thing
here with a roof.
The awning SAGS, and that is the whole model. A flat sheet on four posts is a
table with a lid; cloth slung between four points hangs, and the dip is what
says it is cloth before the colour does. It costs nothing:
`dishedSheetGeometry` bends its cross section by `curve`, and one turn about X
maps that bend onto the world's vertical, so the sag is the helper's own
parameter rather than anything hand-built. Per level, because the reference's
front edge dips further than its back — cloth pulled over a ridge and left
loose at the eaves does not hang symmetrically.
Three faults, each of them a thing I had drawn correctly and built wrong:
- The posts were one height, and the cloth is not one height. It is a
parabola across its length and deeper at the front than the back, so a
single post reached some corners and not others: the awning came away as
its own floating piece 67 mm above the post heads, held up in the drawing
and by nothing in the geometry. Each post is now sized by the sheet's OWN
arithmetic — same parabola, same per-level sag, same quarter turn, same
tilt — rather than by a second version of it that can drift.
- The legs ran up to the rail's top face and ended level with it. Two upward
faces in the plane y = 0.745, at all four corners. A leg is housed in a
rail, not flush with it.
- The posts stopped at the rail's underside, which put their feet in ITS
plane — the same fault one storey down. They now run past it and finish as
a stub below, which is the reference's detail as well as the fix.
And one thing the render corrected rather than the checks: the posts were
inboard, so the counter's boards had posts driven through them a hand's
breadth from each end. That is not how a stall is built and not what the
reference shows — the posts stand at the ends and the top lies between them.
The sag came down from 0.17 of the depth to 0.10 for the same reason: at 0.17
the cloth dropped a tenth of its own span and read as a hammock.
38 models, 32 700 triangles, all checks pass, 0 floating cases, GLB round-trip
clean, Conformant, documentation in step — including the showcase arithmetic,
which every new model moves.
