Thin Extrude builds walls of a set thickness along sketch curves, open chains and closed loops, with the wall centred, inside, outside or on both sides at two thicknesses. Saved under format 20 (thin on an Extrude); an extrude without thin saves as before. Closes#721.
A flat face that no construction certificate names on its own now attaches by its exact history name (a new lineage face certificate): cut walls and floors, chamfer faces, each pattern or mirror copy, side walls a Join merged, and the pieces a later feature split a face into. Construction certificates still come first; a seed keeps its certificate when it is patterned. Two flush extrudes of one outline joined end to end keep their exact history in the prism boolean. Face sketch 52% -> 71%, offset plane 52% -> 71%, press-pull/extrude from face 41% -> 60% in the action matrix; baseline blessed.
Fixes#491, fixes#492, fixes#493, fixes#557.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A sketch on a flat face of a sheet metal body was refused ("this face has no exact planar
source"), so the only way was a plane frozen in space. When the sheet changes (a flange's
angle, the thickness), the frozen sketch stays behind: a cut from it fails on the slanted
flange or leaves a blind pocket in the thicker sheet.
`sketch.create` with a face of a sheet metal body now attaches the sketch to the panel the
face belongs to. It keeps the face's name, `sheet:<body>:<panel>:<top|bottom>` (the panel is
the base or a flange's feature tag), and takes the panel's exact plane from its flat region
and fold each time the model is evaluated, so the sketch follows the sheet through parameter
changes, unfold and refold. Its coordinates are the flat pattern's (the bottom face's y
mirrored). A face that is gone is reported as a lost attachment, never replaced by the
nearest face. The attachment follows a renamed or copied body, shows as `sheet_face` in the
command result and as its own status in Redefine Sketch Plane. `fixed: true` still freezes.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Lasse Lian