Chamfers with two distances or a distance and an angle (distance2 / angle, flip for which face comes first), on straight edges between planar faces; pattern copies keep them

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL

crates/doc/src/document.rs

@@ -176,6 +176,15 @@ pub enum FeatureKind {
     Chamfer {
         edges: Vec<Vec3>,
         distance: String,
+        /// Unequal chamfers: the distance along the second face…
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        distance2: Option<String>,
+        /// …or the angle the chamfer makes with the first face.
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        angle: Option<String>,
+        /// Swap which face is the first (by default the one facing up most).
+        #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+        flip: bool,
         #[serde(default, skip_serializing_if = "Option::is_none")]
         body: Option<String>,
     },
@@ -923,7 +932,11 @@ impl FeatureKind {
             }
             FeatureKind::Revolve { angle, .. } => v.push(angle),
             FeatureKind::Fillet { radius, .. } => v.push(radius),
-            FeatureKind::Chamfer { distance, .. } => v.push(distance),
+            FeatureKind::Chamfer { distance, distance2, angle, .. } => {
+                v.push(distance);
+                v.extend(distance2.iter().map(String::as_str));
+                v.extend(angle.iter().map(String::as_str));
+            }
             FeatureKind::Box { length, width, height, .. } => v.extend([length.as_str(), width, height]),
             FeatureKind::Cylinder { radius, height, .. } => v.extend([radius.as_str(), height]),
             FeatureKind::Sphere { radius, .. } => v.push(radius),

crates/doc/src/eval.rs

@@ -1726,10 +1726,9 @@ fn replay(doc: &Document, vals: &BTreeMap<String, Value>, f: &Feature, st: &mut
                 let moved: Vec<Vec3> = edges.iter().map(|p| crate::apply_point(m, *p)).collect();
                 let ti = blend_target(st, &None, &moved)?;
                 let Some(mb) = st.bodies.get(ti).cloned() else { continue };
-                let nb = if matches!(src.kind, FeatureKind::Fillet { .. }) {
-                    kernel::fillet(&mb.body, &moved, r)?
-                } else {
-                    kernel::chamfer(&mb.body, &moved, r)?
+                let nb = match &src.kind {
+                    FeatureKind::Chamfer { distance2, angle, flip, .. } => chamfer_with(vals, &mb.body, &moved, r, distance2, angle, *flip)?,
+                    _ => kernel::fillet(&mb.body, &moved, r)?,
                 };
                 if let Some(slot) = st.bodies.get_mut(ti) {
                     *slot = ModelBody::new(mb.name, nb, mb.feature);
@@ -1819,6 +1818,27 @@ fn face_plane(st: &ModelState, picked: &Plane, at: Vec3, name: Option<&str>) ->
     }
 }
 
+/// A chamfer, equal or by its second distance or angle.
+fn chamfer_with(
+    vals: &BTreeMap<String, Value>,
+    b: &kernel::Body,
+    edges: &[Vec3],
+    d: f64,
+    distance2: &Option<String>,
+    angle: &Option<String>,
+    flip: bool,
+) -> Result<kernel::Body> {
+    let side = match (distance2, angle) {
+        (Some(e), _) => Some(kernel::ChamferSide::Distance(val(vals, e, Kind::Length)?)),
+        (None, Some(e)) => Some(kernel::ChamferSide::Angle(val(vals, e, Kind::Angle)?)),
+        (None, None) => None,
+    };
+    Ok(match side {
+        Some(s) => kernel::chamfer_sides(b, edges, d, s, flip)?,
+        None => kernel::chamfer(b, edges, d)?,
+    })
+}
+
 fn eval_feature(doc: &Document, vals: &BTreeMap<String, Value>, f: &Feature, st: &mut ModelState, warning: &mut Option<String>) -> Result<()> {
     match &f.kind {
         FeatureKind::SheetBase { .. }
@@ -2000,7 +2020,7 @@ fn eval_feature(doc: &Document, vals: &BTreeMap<String, Value>, f: &Feature, st:
             }
             Ok(())
         }
-        FeatureKind::Fillet { edges, radius, body } | FeatureKind::Chamfer { edges, distance: radius, body } => {
+        FeatureKind::Fillet { edges, radius, body } | FeatureKind::Chamfer { edges, distance: radius, body, .. } => {
             let r = val(vals, radius, Kind::Length)?;
             let ti = blend_target(st, body, edges)?;
             let Some(mb) = st.bodies.get(ti) else { return Err(DocError::Invalid("body".into())) };
@@ -2042,10 +2062,10 @@ fn eval_feature(doc: &Document, vals: &BTreeMap<String, Value>, f: &Feature, st:
             } else {
                 resolve_edges(&mb.body, edges, &f.edge_refs, warning)?
             };
-            let nb = if matches!(f.kind, FeatureKind::Fillet { .. }) {
-                kernel::fillet(&mb.body, &edges, r)?
-            } else {
-                kernel::chamfer(&mb.body, &edges, r)?
+            let nb = match &f.kind {
+                FeatureKind::Fillet { .. } => kernel::fillet(&mb.body, &edges, r)?,
+                FeatureKind::Chamfer { distance2, angle, flip, .. } => chamfer_with(vals, &mb.body, &edges, r, distance2, angle, *flip)?,
+                _ => return Err(DocError::Invalid("blend".into())),
             };
             let (name, feat) = (mb.name.clone(), mb.feature);
             if let Some(slot) = st.bodies.get_mut(ti) {

crates/doc/src/params.rs

@@ -49,7 +49,15 @@ impl FeatureKind {
             }
             FeatureKind::Revolve { angle, .. } => v.push(("Angle", angle, A)),
             FeatureKind::Fillet { radius, .. } => v.push(("Radius", radius, L)),
-            FeatureKind::Chamfer { distance, .. } => v.push(("Distance", distance, L)),
+            FeatureKind::Chamfer { distance, distance2, angle, .. } => {
+                v.push(("Distance", distance, L));
+                if let Some(d) = distance2 {
+                    v.push(("Distance 2", d, L));
+                }
+                if let Some(a) = angle {
+                    v.push(("Angle", a, A));
+                }
+            }
             FeatureKind::Box { length, width, height, .. } => {
                 v.push(("Length", length, L));
                 v.push(("Width", width, L));

crates/engine/src/cmd/features.rs

@@ -32,7 +32,7 @@ pub static COMMANDS: &[CommandSpec] = &[
         .icon("fillet")
         .key("F")
         .params("edges: [[x,y,z] point on edge | {body, index}]; radius: expr; body?"),
-    CommandSpec::new("FusionChamferCommand", "Chamfer", chamfer).at("SOLID", "MODIFY").icon("chamfer").params("edges: [[x,y,z] | {body, index}]; distance: expr; body?"),
+    CommandSpec::new("FusionChamferCommand", "Chamfer", chamfer).at("SOLID", "MODIFY").icon("chamfer").params("edges: [[x,y,z] | {body, index}]; distance: expr; distance2?: expr (along the second face) | angle?: expr (from the first face); flip?: bool (which face is first: by default the one facing up most); body?"),
     CommandSpec::new("FusionCombineCommand", "Combine", combine).at("SOLID", "MODIFY").icon("combine").params("target: body; tools: [body]; operation?: join|cut|intersect; keep_tools?: bool"),
     CommandSpec::new("PatternRectangular", "Rectangular Pattern", pattern_rect)
         .at("SOLID", "CREATE")
@@ -497,7 +497,18 @@ fn chamfer(s: &mut Session, p: &Value) -> Result<Value> {
     let edges = edge_points(s, p, cmd)?;
     let distance = req_expr(cmd, p, "distance")?;
     check_expr(s, &distance, Kind::Length, cmd, "distance")?;
-    add_feature(s, p, FeatureKind::Chamfer { edges, distance, body: str_(p, "body").map(str::to_string) })
+    let (distance2, angle) = (expr(p, "distance2"), expr(p, "angle"));
+    if let Some(d) = &distance2 {
+        check_expr(s, d, Kind::Length, cmd, "distance2")?;
+    }
+    if let Some(a) = &angle {
+        check_expr(s, a, Kind::Angle, cmd, "angle")?;
+    }
+    if distance2.is_some() && angle.is_some() {
+        return Err(bad(cmd, "give `distance2` or `angle`, not both"));
+    }
+    let flip = bool_(p, "flip").unwrap_or(false);
+    add_feature(s, p, FeatureKind::Chamfer { edges, distance, distance2, angle, flip, body: str_(p, "body").map(str::to_string) })
 }
 
 fn combine(s: &mut Session, p: &Value) -> Result<Value> {

crates/engine/src/tests.rs

@@ -1412,3 +1412,18 @@ fn press_pull_on_curved_faces() {
     let v1 = volume(&mut s);
     assert!(rel(v1 - v0, PI * (25.0 - 16.0) * 20.0) < 1e-3, "{v0} {v1}");
 }
+
+/// Chamfers with two distances or a distance and an angle.
+#[test]
+fn unequal_chamfers() {
+    let mut s = Session::default();
+    run(&mut s, "PrimitiveBox", json!({"length": 40, "width": 30, "height": 20}));
+    // Top front edge: 2 along the top (the face facing up), 4 down the front.
+    run(&mut s, "FusionChamferCommand", json!({"edges": [[20, 0, 20]], "distance": 2, "distance2": 4}));
+    assert!(rel(volume(&mut s), 24000.0 - 0.5 * 2.0 * 4.0 * 40.0) < 1e-6, "{}", volume(&mut s));
+    // Bottom back edge: 3 along the bottom, at 30° from it (down the back face 3·tan 30°).
+    run(&mut s, "FusionChamferCommand", json!({"edges": [[20, 30, 0]], "distance": 3, "angle": "30 deg", "flip": true}));
+    let d2 = 3.0 * (30f64).to_radians().tan();
+    assert!(rel(volume(&mut s), 24000.0 - 160.0 - 0.5 * 3.0 * d2 * 40.0) < 1e-6, "{}", volume(&mut s));
+    assert!(s.execute("FusionChamferCommand", &json!({"edges": [[0, 15, 20]], "distance": 1, "distance2": 2, "angle": "30 deg"})).is_err());
+}

crates/kernel/src/blend.rs

@@ -762,16 +762,79 @@ fn edge_frame(cur: &Body, p: Vec3) -> Result<EdgeFrame> {
 
 /// The prism that cuts a chamfer of size `s` on the edge nearest `p`. `k` varies the parts that
 /// stay outside the body so that neighbouring cutters don't share edges.
+/// The second side of an unequal chamfer: a distance along the other face, or the angle the
+/// chamfer makes with the first face.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum ChamferSide {
+    Distance(f64),
+    Angle(f64),
+}
+
+/// A chamfer with different setbacks on the two faces of each (straight) edge: `d1` along the
+/// first face (the one facing up most, the other with `flip`), the second side by distance or
+/// angle.
+pub fn chamfer_sides(body: &Body, edges: &[Vec3], d1: f64, side: ChamferSide, flip: bool) -> Result<Body> {
+    body.require_brep("chamfer")?;
+    let ok = |x: f64| x.is_finite() && x > 1e-6 && x < 1e6;
+    let valid = ok(d1)
+        && match side {
+            ChamferSide::Distance(d) => ok(d),
+            ChamferSide::Angle(a) => a.is_finite() && a > 1e-3 && a < std::f64::consts::PI - 1e-3,
+        };
+    if !valid {
+        return Err(KernelError::Invalid("chamfer sizes must be positive (the angle within 0°…180°)".into()));
+    }
+    if edges.is_empty() || edges.len() > 1000 {
+        return Err(KernelError::Invalid("select 1…1000 edges".into()));
+    }
+    let mut cur = body.clone();
+    for (k, p) in edges.iter().enumerate() {
+        let t = chamfer_tool_sides(&cur, *p, d1, Some((side, flip)), k)?;
+        cur = crate::ops::boolean(&cur, &t, crate::BoolOp::Cut)?.ok_or_else(|| KernelError::Failed("the chamfer removed everything".into()))?;
+    }
+    Ok(cur)
+}
+
 pub(crate) fn chamfer_tool(cur: &Body, p: Vec3, s: f64, k: usize) -> Result<Body> {
-    let f = edge_frame(cur, p)?;
+    chamfer_tool_sides(cur, p, s, None, k)
+}
+
+fn chamfer_tool_sides(cur: &Body, p: Vec3, s: f64, sides: Option<(ChamferSide, bool)>, k: usize) -> Result<Body> {
+    let mut f = edge_frame(cur, p)?;
+    // Setbacks along each face: equal, or by the second side's rule.
+    let (s1, s2) = match sides {
+        None => (s, s),
+        Some((side, flip)) => {
+            // Side 1: the face facing up most (then +y, +x), unless flipped.
+            let up = Vec3::new(1e-6, 1e-3, 1.0);
+            if (f.n2.dot(up) > f.n1.dot(up)) != flip {
+                std::mem::swap(&mut f.n1, &mut f.n2);
+                std::mem::swap(&mut f.t1, &mut f.t2);
+            }
+            let s2 = match side {
+                ChamferSide::Distance(d) => d,
+                ChamferSide::Angle(a) => {
+                    // The triangle edge–A–B: angle φ at the edge, `a` at A (on face 1).
+                    let phi = f.t1.dot(f.t2).clamp(-1.0, 1.0).acos();
+                    let den = (phi + a).sin();
+                    if den <= 1e-9 {
+                        return Err(KernelError::Invalid("that chamfer angle runs past the other face".into()));
+                    }
+                    s * a.sin() / den
+                }
+            };
+            (s, s2)
+        }
+    };
+    let s = s1.max(s2);
     let size = cur.size();
     let len = f.p0.dist(f.p1);
     let ext = (s * 2.0).max(size * 0.01) * (1.0 + 0.093 * (k % 5) as f64);
     // Cross-section at p0 - d*ext, in a plane with normal d.
     let base = f.p0 - f.d * ext;
     let plane = solvecraft_geom::Plane::from_normal(base, f.d).ok_or_else(|| KernelError::Failed("chamfer plane".into()))?;
-    let a = base + f.t1 * s;
-    let b = base + f.t2 * s;
+    let a = base + f.t1 * s1;
+    let b = base + f.t2 * s2;
     let ab = (a - b).normalized().ok_or_else(|| KernelError::Failed("chamfer".into()))?;
     let out = (f.n1 + f.n2).normalized().ok_or_else(|| KernelError::Failed("chamfer".into()))?;
     let vary = 1.0 + 0.137 * (k % 7) as f64;

crates/kernel/src/lib.rs

@@ -35,7 +35,7 @@ mod step_out;
 mod sweep_path;
 mod topo;
 
-pub use blend::{chamfer, fillet};
+pub use blend::{ChamferSide, chamfer, chamfer_sides, fillet};
 pub use body::{Body, EdgeInfo, FaceInfo, FacePaint, Paint};
 pub use build::{PathSeg, box_solid, cylinder, extrude, extrude_tapered, loft, revolve, sphere, sweep, torus};
 pub use helix::{loft_to_point, sweep_helix};