NOWN-DEVandClaude Opus 5.5
af0440aaab
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>
4.6 KiB
Face-attached sketches
New face-attached sketches store the selected source body, its creating feature, an exact face certificate, and the source and author occurrence paths. The sketch's picked origin and orientation are stored in the source face's canonical plane. Editing the source height or moving its placement therefore updates the sketch plane while preserving its local geometry and dimensions.
Supported planar sources are exact Box faces, untapered New Body Extrude caps and straight sketch sides, and planar faces of immutable STEP imports. Extrude caps also identify their outer boundary and holes by source curve IDs. Reordering profiles cannot substitute another profile's cap. Curved surfaces cannot host a planar sketch through this workflow. Edited surfaces without retained construction provenance, ambiguous sources, and unsupported generators require an explicit fixed plane instead. A nearby or parallel face is never used to repair a new attachment automatically.
The flat faces of a sheet metal body are the exception: they have no construction
certificate, so a sketch on one attaches to its panel by name (sheet:<body>:<panel>:<side>)
and finds it again after every rebuild, unfold and refold. If that panel no longer exists the
sketch reports a lost attachment, as above. See the sheet metal guide.
Create and repair
Select a supported planar face and create a sketch. The desktop selection supplies the exact
body and face index, including its occurrence path. Command callers can use
sketch.create with plane: {face: [x,y,z], body: "world body key", index: face_index};
the point is in world coordinates. A point-only face request must find a unique supported
source. An unsupported or ambiguous request fails with an explanation instead of creating
an attachment with weaker identity.
When a source is suppressed, deleted, replaced, or loses its certificate, the sketch reports a lost attachment. Its saved plane is only a visible repair guide: it does not produce a healthy solved sketch or let downstream features build at a substitute face.
Use Redefine Sketch Plane to select a new supported face explicitly. The draft can be reviewed before applying it; cancellation leaves the existing attachment intact. Reattachment keeps existing sketch geometry, IDs, and dimensions. When the selected source changes, its previous automatically projected boundary becomes ordinary geometry on the new plane; it is not replaced by a newly projected boundary. Rebinding to the same certified source retains its live boundary. Manually created projection links retain their own sources.
Choose an explicit fixed plane to detach the sketch. This preserves its current local geometry and dimensions and converts only its automatically projected face boundary to ordinary geometry. Manual projection links remain attached to their own sources. A fresh fixed-plane sketch has no live face auto-projection.
Occurrences, pending positions, and files
The selected source occurrence and the sketch's author occurrence are separate identities. Repeated instances therefore cannot silently switch an attachment to the first placement. A missing author path also requires explicit repair. Reattachment and creation capture pending positions only on the involved source and author paths. Failed commands restore those pending positions; undo restores the previous attachment and placement state.
File format 11 introduced these optional attachments, which format 12 also preserves. Existing designs with face references without an attachment retain their legacy geometry and lookup behavior when opened; they are not silently upgraded. Redefining such a sketch onto a supported selected face creates the stronger attachment. Unsupported legacy geometry can instead be retained on an explicit fixed plane. Imported attachments also bind the exact STEP payload digest, item entity, and face entity: replacing the payload cannot reuse an old attachment merely because a face index or shape looks the same.
Profiles generated by face modelling commands
Extrude, Revolve, and Press Pull can generate an internal sketch from a selected planar face. Supported sources use the same certified attachment and live boundary as an ordinary attached sketch. For modified faces without a construction certificate, these commands retain their historical named-face and linked-boundary behaviour through a private compatibility path. Initial capture uses the selected body and face index. These helper sketches do not have the stronger saved identity guarantee of a certified attachment. This compatibility path does not change the requirements for creating an ordinary face-attached sketch.