Sheet metal rims and holes, plastic features, lofts, raised pieces and merged walls take face attachments (#677)

Sheet metal rims and bend ends attach by name (<panel>:rim.<edge>, <flange>:rim.bend0/1), as do face profiles from sheet faces. A plain or counterbored Hole square to a panel is machined into the flat pattern. Boss, Lip, Rest and Snap Fit keep the body's history and name their own faces. Hole tools name their faces by the part they cut, and pattern copies as copies. A pattern's repeated fillets keep the body's history. Loft sides are named by their section curves. A piece Offset Face moved off its face's plane attaches by its own qualified name. Sides of a profile grown to overlap a flush body keep their sketch line's name, so walls a Join merged take a sketch (#681). Face sketch 75% -> 90%, offset plane 75% -> 90%, press-pull/extrude 64% -> 85% in the action matrix; baseline blessed.

Fixes #494, fixes #495, fixes #560, fixes #561, fixes #563, fixes #564, fixes #681.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/cmd/sheet_tests.rs

@@ -3023,3 +3023,79 @@ fn fold_fixed_point_must_touch_the_sheet_but_any_face_will_do() {
     assert!(fold["warning"].as_str().is_some_and(|w| w.contains("fixed point is not on the sheet")), "{fold}");
     assert!((bbox(&mut f)["max"][0].as_f64().unwrap_or(f64::NAN) - x).abs() < 1e-6, "the right side stays");
 }
+
+/// The middle of the largest triangle of each flat face of the first body: well inside it.
+fn flat_face_points(s: &Session) -> Vec<(usize, solidcraft_geom::Vec3, solidcraft_geom::Vec3)> {
+    let state = s.model.state();
+    let body = &state.bodies[0].body;
+    let mesh = body.tessellate(0.01).unwrap();
+    (0..body.face_count())
+        .filter_map(|index| {
+            let normal = body.planar_face(index)?.normal();
+            let point = mesh
+                .triangles
+                .iter()
+                .zip(&mesh.tri_face)
+                .filter(|(_, f)| **f as usize == index)
+                .filter_map(|(t, _)| mesh.tri(t))
+                .max_by(|[a, b, c], [d, e, f]| (*b - *a).cross(*c - *a).len().total_cmp(&(*e - *d).cross(*f - *d).len()))
+                .map(|[a, b, c]| (a + b + c) * (1.0 / 3.0))?;
+            Some((index, point, normal))
+        })
+        .collect()
+}
+
+/// Every flat face of a sheet takes an attached sketch (#495): its panels, the rims along the
+/// panels' straight edges (named by the base sketch line or the flange's far edge and sides) and
+/// the flat ends of a bend. Each lies on its face, facing out of the sheet, and a rim's sketch
+/// follows the rim when the base grows. A press-pull on a rim pushes it out, and a plain hole into
+/// a panel is kept as a cut-out of the flat pattern (#560).
+#[test]
+fn every_flat_face_of_a_sheet_takes_an_attached_sketch() {
+    let mut s = Session::default();
+    run(&mut s, "parameters.add", json!({"name": "W", "expression": "100 mm"}));
+    run(&mut s, "sketch.create", json!({"plane": "XY", "name": "Base"}));
+    run(&mut s, "sketch.rectangle.two_point", json!({"p0": [0, 0], "p1": [100, 60]}));
+    run(&mut s, "sketch.constraint.fix", json!({"entities": ["p1"]}));
+    run(&mut s, "sketch.dimension", json!({"entities": ["l1"], "value": "W"}));
+    run(&mut s, "sketch.finish", json!({}));
+    run(&mut s, "sheet.flange", json!({"sketch": "Base"}));
+    run(&mut s, "sheet.flange", json!({"edges": [[50, 0, 2.5]], "height": 20}));
+    let faces = flat_face_points(&s);
+    // The base: its two faces and three rims (the fourth edge bends); the flange: its two faces,
+    // its far rim and two sides; the two ends of the bend.
+    assert_eq!(faces.len(), 12);
+    let mut on_side = None;
+    for (index, point, normal) in faces {
+        let made = run(&mut s, "sketch.create", json!({"plane": {"face": point, "body": "Body1", "index": index}}));
+        run(&mut s, "sketch.finish", json!({}));
+        assert_eq!(made["attachment"], "sheet_face", "face {index} at {point:?}");
+        let id = made["sketch"].as_u64().unwrap();
+        let solidcraft_doc::FaceAttachmentStatus::Sheet { plane: Some(plane) } = s.placed_document().sketch_face_attachment(id, &s.model) else {
+            panic!("face {index} at {point:?}")
+        };
+        assert!(plane.normal().dot(normal) > 1.0 - 1e-9 && (point - plane.origin).dot(normal).abs() < 1e-6, "face {index}: {plane:?}");
+        if (point.x - 100.0).abs() < 1e-6 && point.y > 10.0 {
+            on_side = Some(id);
+        }
+    }
+    // The base's rim along x = W (the sketch's l2) moves with W.
+    let side = on_side.expect("the base rim on x = 100");
+    run(&mut s, "parameters.change", json!({"name": "W", "expression": "120 mm"}));
+    let solidcraft_doc::FaceAttachmentStatus::Sheet { plane: Some(plane) } = s.placed_document().sketch_face_attachment(side, &s.model) else {
+        panic!("the rim sketch after the edit")
+    };
+    assert!((plane.origin.x - 120.0).abs() < 1e-9 && (plane.normal().x - 1.0).abs() < 1e-9, "{plane:?}");
+    // Press-pull the rim 5 mm out: the base grows by 5 x 60 x 2.5 less what the flange covers.
+    let v0 = volume(&mut s);
+    run(&mut s, "solid.press_pull", json!({"face": [120, 30, 1.25], "distance": 5}));
+    assert!(volume(&mut s) > v0 + 5.0 * 50.0 * 2.5, "{} {v0}", volume(&mut s));
+    // A plain hole into the base is a cut-out of the flat pattern.
+    let mut t = Session::default();
+    plate_with_flange(&mut t);
+    let v0 = volume(&mut t);
+    run(&mut t, "solid.hole", json!({"position": [50, 30, 2.5], "direction": [0, 0, -1], "diameter": 6}));
+    assert!((v0 - volume(&mut t) - PI * 9.0 * 2.5).abs() < 0.1, "{}", v0 - volume(&mut t));
+    let f = flat(&mut t);
+    assert_eq!(f["cutouts"].as_array().map(Vec::len), Some(1), "{f}");
+}