Files
OneCAD/crates/kernel/src/fill.rs
T
Irakli KourtisandClaude Opus 5.5 201e9d5f9f Patch fills non-planar edge loops with one smooth face (#250) (#472)
* Add a one-surface fill of closed 3D loops to geom

A closed loop of curves that does not lie in a plane has no exact surface;
the usual answer is one smooth face fitted over it. fill_loop does that:

- the loop's best-fit plane (Newell normal), with a frame chosen from the
  loop itself so the result does not depend on where the loop starts, its
  direction, or where the part sits
- the loop seen along that normal must be simple and must not fold or run
  along the normal; otherwise it is refused ("not supported yet"), never
  filled with wrong geometry
- one non-rational bicubic B-spline height field over the loop's box,
  fitted by least squares to the loop's samples (The NURBS Book 9.4.1,
  9.4.3, eq. 9.62/9.65) with a thin-plate smoothness term
  lambda*A*int(h_uu^2 + 2 h_uv^2 + h_vv^2), A one grid cell's area, so the
  fit is the same at any scale; only planes are reproduced exactly
- span counts per direction (long narrow loops fit), refined until the
  loop is within tolerance, else refused with the deviation reached

bspline: bisected span search, basis functions on a stack array, one
clamping helper shared by curves and surfaces, one binomial helper.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J53sR6gEaVt56soFDpTck8

* Patch fills non-planar loops of edges with one smooth face (#250)

surface.patch with edges refused any loop that is not planar ("not
supported yet: patching a loop that is not planar"). It now fills it:

- planar loops still get one exact planar face, but planarity is certified
  conservatively: lines by their ends, B-spline/NURBS edges by their control
  points, intersection curves by their samples lying on a support plane
  within tolerance; a loop that can't be certified is filled instead
- other loops get one face from geom's fill_loop, bounded by the body's own
  chained edges, whole (no split): its history is one generated face whose
  edges are the body's, and it stitches back into a closed solid
- intersection-curve edges are sampled by a seeded, guarded double
  projection shared by the planarity test and the fill (plane_fit)
- the face tolerance is 10x the planarity tolerance (documented: later
  operations take the face to contain its edges within it)
- edge picking runs inside the guard; the geom->truck conversion is shared
  with the T-spline sheets (spline_conv); the Newell plane fit is shared with
  STEP import

Tests: 3- to 8-sided, concave (dart, arrow, plus), flat-corner, two-edge and
imported rims fill as one face and stitch closed (volumes against an
independent integral); finite mesh normals, same result for any pick order
or placement; non-height-field loops and too-fine detail are refused.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J53sR6gEaVt56soFDpTck8

* Test the Patch dialog filling a non-planar loop of picked edges

The Patch dialog's only test used a sketch profile. Picking the four
curved rim edges of a box cut by a sideways cylinder now makes one
surface.patch command whose result is a single smooth face over the rim.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J53sR6gEaVt56soFDpTck8

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-12 21:37:01 -04:00

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//! Filling a closed loop of a body's edges that is not planar with one face: a B-spline height
//! field over the loop's best-fit plane (`solidcraft_geom::fill::fill_loop`), bounded by the
//! body's own edges, whole. Loops that do not bound a height field over a plane are refused.
use solidcraft_geom::Vec3;
use solidcraft_geom::bspline::SplineError;
use truck_modeling as mt;
use crate::body::{Body, from_p3};
use crate::plane_fit::EdgeSampler;
use crate::record::{Rebuild, rebuilt_body};
use crate::{KernelError, Result};
/// A surface body of one face filling the closed loop `chain` of `body`'s edges (each edge
/// oriented along the loop, each ending where the next starts), within [`face_tolerance`] of
/// every edge. Its history is over `[body]`: the face is new, its edges the body's own. Call it
/// under [`crate::guard`].
pub(crate) fn fill_loop(body: &Body, chain: &[mt::Edge]) -> Result<Body> {
let tol = face_tolerance(body);
let mut sides: Vec<(EdgeSampler, Vec3)> = Vec::with_capacity(chain.len());
for e in chain {
let sampler = EdgeSampler::new(e).ok_or_else(|| KernelError::Invalid("an edge has no parameter range".into()))?;
sides.push((sampler, from_p3(e.front().point())));
}
let mut point = |k: usize, t: f64| -> Option<Vec3> {
let (sampler, start) = sides.get_mut(k)?;
// The loop's corners are its vertices (an imported edge's curve may end a little off).
if t <= 0.0 { Some(*start) } else { sampler.at(t) }
};
let fill = solidcraft_geom::fill::fill_loop(chain.len(), &mut point, tol).map_err(|e| match e {
SplineError::Unsupported(m) => KernelError::Invalid(format!("not supported yet: {m}")),
other => KernelError::Invalid(format!("cannot fill the loop: {other}")),
})?;
// The wire runs counter-clockwise about the surface's normal.
let wire: mt::Wire =
if fill.counter_clockwise { chain.to_vec().into() } else { chain.iter().rev().map(mt::Edge::inverse).collect::<Vec<_>>().into() };
let face = mt::Face::try_new(vec![wire], crate::spline_conv::surface(&fill.surface)?).map_err(|e| KernelError::Failed(format!("fill: {e}")))?;
let mut rec = Rebuild::default();
rec.made(&face, Vec::new());
Ok(rebuilt_body(crate::surfaces::surface_body(vec![face]), &[&body.solid], &rec))
}
/// How far a loop's edges may be from a plane for its patch to be that plane: `10⁻⁷` of the
/// body's size, at least the linear tolerance (`10⁻⁶` mm) — the body's own "same point"
/// tolerance, since a planar face is exact and other operations treat it as containing its
/// edges to that tolerance. A fitted face gets [`face_tolerance`], ten times looser.
pub(crate) fn planarity_tolerance(body: &Body) -> f64 {
(body.size() * 1e-7).max(solidcraft_geom::LINEAR_TOL)
}
/// How far the fill's surface may be from the loop's edges: `10⁻⁶` of the body's size, at least
/// `10⁻⁵` mm — ten times [`planarity_tolerance`]. Truck meshes a face from its edges' own
/// polylines (shared with the neighbouring faces), so the mesh stays watertight whatever the
/// gap: measured on a five-sided rim, fills whose edges were up to `4.5·10⁻⁴` mm off the surface
/// meshed cleanly and stitched back into closed solids. Ten times the linear tolerance because a
/// fitted surface approaches curved edges like a cubic spline, so each further factor of ten
/// costs about twice the spans each way, and imported edges may already lie `10⁻⁵` mm or more off
/// their vertices; two orders below what meshing tolerates. Later operations must take the face
/// to contain its edges within this tolerance, not the linear one: the face's edges are the
/// body's exact edges, the surface between them is the fit.
pub(crate) fn face_tolerance(body: &Body) -> f64 {
(body.size() * 1e-6).max(1e-5)
}
#[cfg(test)]
mod tests {
use mt::{BoundedCurve, InnerSpace, MetricSpace, ParametricCurve, ParametricSurface};
use solidcraft_geom::{Loop2, Plane, Region2, Vec2, Vec3};
use truck_modeling as mt;
use crate::body::{Body, from_p3, p3};
use crate::boolean_record::tests::{Reach, checked};
use crate::history::{Change, EdgeOrigin};
use crate::{BoolOp, boolean, copy_faces, cylinder, extrude, measure, patch_edges, stitch};
/// The cutting cylinder: axis along y at x = 0, z = 50, radius 40, so the top of a prism
/// within 20 of the axis and 20 high is cut away everywhere (to between 10 and 15.4 mm).
fn cut_height(x: f64) -> f64 {
50.0 - (1600.0 - x * x).sqrt()
}
/// A prism on the polygon `corners`, 20 high, its top cut by the cylinder; the cut solid, the
/// open cup without its top, and a point on each rim edge (the edges' midpoints in plan).
/// `inside` is a point inside the polygon.
fn cup(corners: &[Vec2], inside: Vec2) -> (Body, Body, Vec<Vec3>) {
let prism = extrude(&Plane::XY, &[Region2 { outer: Loop2::polygon(corners), holes: vec![] }], 0.0, 20.0).unwrap().pop().unwrap();
let tool = cylinder(Vec3::new(0.0, -60.0, 50.0), Vec3::Y, 40.0, 120.0).unwrap();
let solid = boolean(&prism, &tool, BoolOp::Cut).unwrap().unwrap();
let n = corners.len();
let mut keep = vec![inside.extend(0.0)];
let mut rim = Vec::new();
for k in 0..n {
let m = corners[k].lerp(corners[(k + 1) % n], 0.5);
keep.push(m.extend(5.0));
rim.push(m.extend(cut_height(m.x)));
}
let open = copy_faces(&solid, &keep).unwrap();
assert!(open.is_surface());
(solid, open, rim)
}
fn regular(n: usize, phase: f64) -> Vec<Vec2> {
(0..n).map(|k| Vec2::from_angle(phase + k as f64 * std::f64::consts::TAU / n as f64) * 20.0).collect()
}
/// The distance from `p` to the surface: the nearest of a grid of samples, then Gauss–Newton
/// within the domain.
fn to_surface(s: &mt::Surface, p: mt::Point3) -> f64 {
let (Some((u0, u1)), Some((v0, v1))) = s.try_range_tuple() else { panic!("a bounded surface") };
let n = 80;
let mut best = (f64::MAX, u0, v0);
for i in 0..=n {
for j in 0..=n {
let (u, v) = (u0 + (u1 - u0) * i as f64 / n as f64, v0 + (v1 - v0) * j as f64 / n as f64);
let d = s.subs(u, v).distance(p);
if d < best.0 {
best = (d, u, v);
}
}
}
let (_, mut u, mut v) = best;
for _ in 0..50 {
let (q, a, b) = (s.subs(u, v), s.uder(u, v), s.vder(u, v));
let r = q - p;
let (aa, ab, bb) = (a.dot(a), a.dot(b), b.dot(b));
let det = aa * bb - ab * ab;
if det.abs() < 1e-300 {
break;
}
let (ga, gb) = (a.dot(r), b.dot(r));
u = (u - (bb * ga - ab * gb) / det).clamp(u0, u1);
v = (v - (aa * gb - ab * ga) / det).clamp(v0, v1);
}
s.subs(u, v).distance(p)
}
/// The farthest point along the face's edges from its surface.
fn edges_off_surface(face: &mt::Face) -> f64 {
let s = face.surface();
let mut worst = 0.0f64;
for e in face.boundaries().iter().flat_map(|w| w.edge_iter()) {
let c = e.curve();
let (t0, t1) = c.range_tuple();
for k in 0..=24 {
worst = worst.max(to_surface(&s, c.subs(t0 + (t1 - t0) * k as f64 / 24.0)));
}
}
worst
}
/// The fill's mesh: every normal finite, and no triangle folded over (all face the same way
/// as the mesh's total area vector, by a clear margin).
fn mesh_is_clean(fill: &Body) -> f64 {
let m = fill.tessellate(0.01).unwrap();
assert!(!m.triangles.is_empty());
assert!(m.normals.iter().all(|n| n.is_finite() && n.len() > 0.5), "a mesh normal is not finite");
let tri = |t: &[u32; 3]| m.tri(t).unwrap();
let total = m.triangles.iter().map(|t| {
let [a, b, c] = tri(t);
(b - a).cross(c - a)
});
let total = total.fold(Vec3::ZERO, |s, v| s + v);
let n = total.normalized().unwrap();
for t in &m.triangles {
let [a, b, c] = tri(t);
let v = (b - a).cross(c - a);
if v.len() > 1e-12 {
assert!(v.dot(n) > 0.0, "a folded triangle");
}
}
measure(fill).unwrap().area
}
/// Fill the rim, check the face, stitch it back: (the fill, the closed solid's volume).
fn fill_rim(open: &Body, rim: &[Vec3]) -> (Body, f64) {
let fill = patch_edges(open, rim).unwrap();
assert!(fill.is_surface());
assert_eq!(fill.face_count(), 1, "one face");
let face = fill.solid.face_iter().next().unwrap().clone();
assert!(!matches!(face.surface(), mt::Surface::Plane(_)));
// Its edges are the open body's own, by identity, and nothing else.
let own: Vec<mt::EdgeID> = open.solid.edge_iter().map(|e| e.id()).collect();
assert!(fill.solid.edge_iter().all(|e| own.contains(&e.id())), "an edge that is not the body's");
let h = checked(&fill, &[open], 0.05, Reach { made: 0.0, moved: 0.0 }, &|_| true);
assert!(h.faces.iter().all(|f| f.change == Change::Generated && f.origins.is_empty()));
assert!(h.edges.iter().all(|e| matches!(e.origins.as_slice(), [EdgeOrigin::Edge { operand: 0, .. }])));
let off = edges_off_surface(&face);
let tol = super::face_tolerance(open);
assert!(off <= tol, "an edge is {off} off the face (tolerance {tol})");
mesh_is_clean(&fill);
let closed = stitch(&[open, &fill], 0.0).unwrap();
assert!(!closed.is_surface(), "the fill closes the cup");
(fill, measure(&closed).unwrap().volume)
}
/// The fill's height over the point `(x, y)`: Newton's method on the surface's `x`, `y` from
/// the nearest of a grid of samples.
fn height_over(s: &mt::Surface, x: f64, y: f64, start: &mut Option<(f64, f64)>) -> Option<f64> {
let (Some((u0, u1)), Some((v0, v1))) = s.try_range_tuple() else { return None };
let (mut u, mut v) = start.unwrap_or(((u0 + u1) / 2.0, (v0 + v1) / 2.0));
for _ in 0..30 {
let (q, a, b) = (s.subs(u, v), s.uder(u, v), s.vder(u, v));
let (rx, ry) = (q.x - x, q.y - y);
let det = a.x * b.y - a.y * b.x;
if det.abs() < 1e-300 {
return None;
}
u = (u - (b.y * rx - b.x * ry) / det).clamp(u0, u1);
v = (v - (a.x * ry - a.y * rx) / det).clamp(v0, v1);
}
let q = s.subs(u, v);
*start = Some((u, v));
((q.x - x).hypot(q.y - y) < 1e-9).then_some(q.z)
}
/// The volume the cut prism gains with the fill for its top: the fill's height above the
/// cylinder integrated over the polygon (midpoint rule on a 300 × 300 grid; the integrand
/// vanishes on the rim, so cells across it add little error).
fn gained(fill: &Body, corners: &[Vec2]) -> f64 {
let s = fill.solid.face_iter().next().unwrap().surface();
let (lo, hi) = corners.iter().fold((Vec2::new(f64::MAX, f64::MAX), Vec2::new(f64::MIN, f64::MIN)), |(lo, hi), p| {
(Vec2::new(lo.x.min(p.x), lo.y.min(p.y)), Vec2::new(hi.x.max(p.x), hi.y.max(p.y)))
});
let n = 300;
let (dx, dy) = ((hi.x - lo.x) / n as f64, (hi.y - lo.y) / n as f64);
let inside = |x: f64, y: f64| {
let mut w = false;
for k in 0..corners.len() {
let (a, b) = (corners[k], corners[(k + 1) % corners.len()]);
if (a.y > y) != (b.y > y) && x < a.x + (y - a.y) / (b.y - a.y) * (b.x - a.x) {
w = !w;
}
}
w
};
let mut sum = 0.0;
let mut start = None;
for i in 0..n {
let x = lo.x + (i as f64 + 0.5) * dx;
for j in 0..n {
let y = lo.y + (j as f64 + 0.5) * dy;
if inside(x, y) {
let h = height_over(&s, x, y, &mut start).expect("the fill covers the polygon");
sum += (h - cut_height(x)) * dx * dy;
}
}
}
sum
}
/// The closed solid's volume against the cut prism's plus what the fill adds over the
/// cylinder (integrated independently, [`gained`]); they agree to the integration's error
/// (0.1% of what the fill adds) plus the error of measuring both solids on meshes
/// (`5·10⁻⁵` of the volume).
fn check_volume(name: &str, solid: &Body, fill: &Body, corners: &[Vec2], got: f64) {
let prism = measure(solid).unwrap().volume;
let extra = gained(fill, corners);
let want = prism + extra;
let bound = 1e-3 * extra.abs() + 5e-5 * want;
eprintln!("{name}: closed volume {got:.4}, cut prism {prism:.4} + fill above the cylinder {extra:.4} = {want:.4} (bound ±{bound:.4})");
assert!((got - want).abs() <= bound, "{name}: {got} vs {want}");
}
#[test]
fn regular_rims_of_three_to_eight_sides_fill_with_one_face_and_close_the_cup() {
for n in 3..=8 {
let corners = regular(n, 0.3);
let (solid, open, rim) = cup(&corners, Vec2::ZERO);
let (fill, got) = fill_rim(&open, &rim);
assert_eq!(fill.edge_count(), n, "the rim's own edges");
check_volume(&format!("{n} sides"), &solid, &fill, &corners, got);
}
}
#[test]
fn concave_rims_fill_with_one_face() {
let v = |x: f64, y: f64| Vec2::new(x, y);
let shapes = [
("dart", vec![v(-10.0, 0.0), v(15.0, -12.0), v(3.0, 0.0), v(15.0, 12.0)], v(0.0, 0.0)),
("arrow", vec![v(-12.0, 0.0), v(0.0, -10.0), v(0.0, -4.0), v(14.0, 0.0), v(0.0, 4.0)], v(0.0, 0.0)),
(
"plus",
vec![
v(-4.0, -14.0),
v(4.0, -14.0),
v(4.0, -4.0),
v(14.0, -4.0),
v(14.0, 4.0),
v(4.0, 4.0),
v(4.0, 14.0),
v(-4.0, 14.0),
v(-4.0, 4.0),
v(-14.0, 4.0),
v(-14.0, -4.0),
v(-4.0, -4.0),
],
v(0.0, 0.0),
),
];
for (name, corners, inside) in shapes {
let (solid, open, rim) = cup(&corners, inside);
let (fill, got) = fill_rim(&open, &rim);
assert_eq!(fill.edge_count(), corners.len(), "{name}: the rim's own edges");
check_volume(name, &solid, &fill, &corners, got);
}
}
#[test]
fn a_flat_corner_between_two_edges_is_kept() {
// A rim of five straight edges, two of them in line (a 180° corner between them), the
// four true corners at different heights; walls hang below it.
let p = |x: f64, y: f64, z: f64| mt::Vertex::new(mt::Point3::new(x, y, z));
let v = [p(-14.0, -14.0, 12.0), p(0.0, -14.0, 12.0), p(14.0, -14.0, 12.0), p(14.0, 14.0, 15.0), p(-14.0, 14.0, 10.0)];
let line = |a: &mt::Vertex, b: &mt::Vertex| mt::Edge::new(a, b, mt::Curve::Line(mt::Line(a.point(), b.point())));
let wire: mt::Wire = (0..5).map(|k| line(&v[k], &v[(k + 1) % 5])).collect::<Vec<_>>().into();
let low = mt::builder::translated(&wire, mt::Vector3::new(0.0, 0.0, -10.0));
let walls = mt::builder::try_wire_homotopy(&wire, &low).unwrap();
let body = crate::surfaces::surface_body(walls.face_iter().cloned().collect());
let rim: Vec<Vec3> = (0..5).map(|k| from_p3(v[k].point()).lerp(from_p3(v[(k + 1) % 5].point()), 0.5)).collect();
let fill = patch_edges(&body, &rim).unwrap();
assert_eq!((fill.face_count(), fill.edge_count()), (1, 5), "one face on all five edges");
let face = fill.solid.face_iter().next().unwrap().clone();
assert!(edges_off_surface(&face) <= super::face_tolerance(&body));
let area = mesh_is_clean(&fill);
eprintln!("flat corner: one face of area {area}");
assert!(area > 28.0 * 28.0 * 0.99 && area < 28.0 * 28.0 * 1.05, "{area}");
}
#[test]
fn the_fill_does_not_depend_on_pick_order_or_where_the_body_is() {
let (_, open, rim) = cup(&regular(5, 0.3), Vec2::ZERO);
let (a, _) = fill_rim(&open, &rim);
let mut shuffled = rim.clone();
shuffled.rotate_left(3);
shuffled.swap(0, 1);
let (b, _) = fill_rim(&open, &shuffled);
let (sa, sb) = (a.solid.face_iter().next().unwrap().surface(), b.solid.face_iter().next().unwrap().surface());
let (Some((u0, u1)), Some((v0, v1))) = sa.try_range_tuple() else { panic!() };
let mut gap = 0.0f64;
for (x, y) in [(0.2, 0.3), (0.5, 0.5), (0.7, 0.9)] {
let (u, v) = (u0 + (u1 - u0) * x, v0 + (v1 - v0) * y);
gap = gap.max(sa.subs(u, v).distance(sb.subs(u, v)));
}
assert!(gap < 1e-7, "pick order moved the surface by {gap}");
let (area_a, area_b) = (mesh_is_clean(&a), mesh_is_clean(&b));
assert!((area_a - area_b).abs() < area_a * 1e-9);
// Moved and turned: the same area.
let moved = crate::transform(&open, Vec3::new(130.0, -70.0, 40.0), Vec3::ZERO, Vec3::new(1.0, 2.0, 3.0), 0.7).unwrap();
let ax = Vec3::new(1.0, 2.0, 3.0).normalized().unwrap();
let turn = |p: Vec3| {
// Rodrigues' rotation by 0.7 about `ax`, then the shift.
let (c, s) = (0.7f64.cos(), 0.7f64.sin());
p * c + ax.cross(p) * s + ax * (ax.dot(p) * (1.0 - c)) + Vec3::new(130.0, -70.0, 40.0)
};
let moved_rim: Vec<Vec3> = rim.iter().map(|p| turn(*p)).collect();
let (c, _) = fill_rim(&moved, &moved_rim);
let area_c = mesh_is_clean(&c);
eprintln!("pick order: surfaces within {gap:e}; areas {area_a} / {area_b} / moved {area_c}");
assert!((area_a - area_c).abs() < area_a * 1e-6, "{area_a} vs moved {area_c}");
}
#[test]
fn a_saddle_rim_of_two_intersection_curves_fills() {
// A round post with its top cut by the sideways cylinder: the rim is two intersection
// curves; the fill is one face on them.
let post = cylinder(Vec3::ZERO, Vec3::Z, 10.0, 20.0).unwrap();
let tool = cylinder(Vec3::new(0.0, -60.0, 50.0), Vec3::Y, 40.0, 120.0).unwrap();
let solid = boolean(&post, &tool, BoolOp::Cut).unwrap().unwrap();
let sides: Vec<Vec3> = (0..8).map(|k| Vec2::from_angle(k as f64 * 0.8).extend(0.0) * 10.0 + Vec3::new(0.0, 0.0, 5.0)).collect();
let open = copy_faces(&solid, &[&[Vec3::ZERO][..], &sides].concat()).unwrap();
let rim: Vec<Vec3> = [-0.98, 2.18]
.map(|a: f64| {
let (x, y) = (10.0 * a.cos(), 10.0 * a.sin());
Vec3::new(x, y, cut_height(x))
})
.to_vec();
let (fill, got) = fill_rim(&open, &rim);
let circle: Vec<Vec2> = (0..720).map(|k| Vec2::from_angle(k as f64 * std::f64::consts::TAU / 720.0) * 10.0).collect();
check_volume("saddle rim", &solid, &fill, &circle, got);
}
#[test]
fn imported_edges_whose_vertices_are_off_their_curves_fill() {
// The cup's vertices moved 2·10⁻⁵ mm off their curves, as a file might give them.
let corners = regular(5, 0.3);
let (solid, open, rim) = cup(&corners, Vec2::ZERO);
let shell = open.solid.boundaries()[0].mapped(
|p: &mt::Point3| *p + mt::Vector3::new(2e-5, 0.0, 0.0),
|c: &mt::Curve| c.clone(),
|s: &mt::Surface| s.clone(),
);
let imported = crate::surfaces::surface_body(shell.face_iter().cloned().collect());
let (fill, got) = fill_rim(&imported, &rim);
check_volume("imported", &solid, &fill, &corners, got);
}
#[test]
fn a_spline_edge_bulging_out_of_plane_is_never_given_a_flat_face() {
// A flat rectangle of edges but for one cubic edge with a control point raised 1.5 mm: no
// plane can be certified. A one-span bump is followed by the fitted face; a narrow one
// (64 spans, about 1 mm wide, its third derivative jumping at every knot) may be beyond
// a 32 × 32 grid, and then it is refused.
for (spans, raised, must_fill) in [(1, 1, true), (64, 30, false)] {
let count = spans + 3;
let pts: Vec<mt::Point3> =
(0..count).map(|i| mt::Point3::new(20.0 * i as f64 / (count - 1) as f64, 0.0, if i == raised { 1.5 } else { 0.0 })).collect();
let spline = mt::BSplineCurve::new(mt::KnotVec::uniform_knot(3, spans), pts);
let v: Vec<mt::Vertex> =
[(0.0, 0.0), (20.0, 0.0), (20.0, 10.0), (0.0, 10.0)].iter().map(|&(x, y)| mt::Vertex::new(mt::Point3::new(x, y, 0.0))).collect();
let line = |a: &mt::Vertex, b: &mt::Vertex| mt::Edge::new(a, b, mt::Curve::Line(mt::Line(a.point(), b.point())));
let bottom = mt::Edge::new(&v[0], &v[1], mt::Curve::BSplineCurve(spline.clone()));
let wire: mt::Wire = vec![bottom, line(&v[1], &v[2]), line(&v[2], &v[3]), line(&v[3], &v[0])].into();
let top = mt::builder::translated(&wire, mt::Vector3::new(0.0, 0.0, -5.0));
let walls = mt::builder::try_wire_homotopy(&wire, &top).unwrap();
let body = crate::surfaces::surface_body(walls.face_iter().cloned().collect());
let peak = from_p3(spline.subs((raised as f64 + 1.0) / (count + 1) as f64));
let rim = [from_p3(spline.subs(0.5)), Vec3::new(20.0, 5.0, 0.0), Vec3::new(10.0, 10.0, 0.0), Vec3::new(0.0, 5.0, 0.0)];
match patch_edges(&body, &rim) {
Ok(fill) => {
let face = fill.solid.face_iter().next().unwrap().clone();
assert!(!matches!(face.surface(), mt::Surface::Plane(_)), "a plane would miss the bulge");
let (off, tol) = (edges_off_surface(&face), super::face_tolerance(&body));
eprintln!("{spans}-span bump: filled, edges within {off:e} of the face");
assert!(off <= tol && to_surface(&face.surface(), p3(peak)) <= tol);
mesh_is_clean(&fill);
}
Err(e) => {
eprintln!("{spans}-span bump: {e}");
assert!(!must_fill && e.to_string().contains("not supported yet"), "{e}");
}
}
}
}
/// A point on each edge that bounds one face of `body` (its free edges).
fn free_edge_points(body: &Body) -> Vec<Vec3> {
let mut uses: std::collections::HashMap<mt::EdgeID, (usize, mt::Edge)> = std::collections::HashMap::new();
for f in body.solid.face_iter() {
for e in f.boundaries().iter().flat_map(|w| w.edge_iter()) {
uses.entry(e.id()).or_insert((0, e.clone())).0 += 1;
}
}
uses.values()
.filter(|(n, _)| *n == 1)
.map(|(_, e)| {
let c = e.curve();
let (t0, t1) = c.range_tuple();
from_p3(c.subs(0.5 * (t0 + t1)))
})
.collect()
}
#[test]
fn a_loop_that_does_not_bound_a_height_field_is_refused() {
// Half a round post's side: two straight edges up and two half circles, whose plane
// stands on the post's axis; the half circles run along its normal at their ends.
let post = cylinder(Vec3::ZERO, Vec3::Z, 10.0, 20.0).unwrap();
let halves = crate::split_by_plane(&post, &Plane::from_normal(Vec3::ZERO, Vec3::X).unwrap()).unwrap();
let half = halves.into_iter().find(|b| measure(b).unwrap().bbox.min.x > -1e-6).unwrap();
let at: Vec<Vec3> =
(-4..=4).map(|k| Vec2::from_angle(k as f64 * 0.35).extend(10.0) * 1.0).map(|p| Vec3::new(p.x * 10.0, p.y * 10.0, 10.0)).collect();
let side = copy_faces(&half, &at).unwrap();
let rim = free_edge_points(&side);
let err = patch_edges(&side, &rim).unwrap_err().to_string();
eprintln!("half a post's side: {err}");
assert!(err.contains("not supported yet"), "{err}");
}
#[test]
fn planar_loops_of_intersection_curves_are_one_planar_face() {
// A round post cut by planes tilted every way, gently to steeply: each rim is an ellipse
// of intersection curves (split where the post's side has seams) lying on the cutting
// plane, so the patch is one planar face, and the post closes again.
for tilt in [Vec3::new(0.0, -0.4, 1.0), Vec3::new(0.7, -0.9, 1.0), Vec3::new(1.3, 0.2, 1.0)] {
let post = cylinder(Vec3::ZERO, Vec3::Z, 10.0, 30.0).unwrap();
let n = tilt.normalized().unwrap();
let plane = Plane::from_normal(Vec3::new(0.0, 0.0, 15.0), n).unwrap();
let pieces = crate::split_by_plane(&post, &plane).unwrap();
let solid = pieces.into_iter().find(|b| measure(b).unwrap().bbox.min.z < 0.5).unwrap();
let height = |x: f64, y: f64| 15.0 - (tilt.x * x + tilt.y * y) / tilt.z;
let sides: Vec<Vec3> = (0..8).map(|k| Vec2::from_angle(k as f64 * 0.8).extend(0.0) * 10.0 + Vec3::new(0.0, 0.0, 1.0)).collect();
let open = copy_faces(&solid, &[&[Vec3::ZERO][..], &sides].concat()).unwrap();
let rim: Vec<Vec3> = (0..12)
.map(|k| {
let a = k as f64 * std::f64::consts::TAU / 12.0 + 0.2;
let (x, y) = (10.0 * a.cos(), 10.0 * a.sin());
Vec3::new(x, y, height(x, y))
})
.collect();
let lid = patch_edges(&open, &rim).unwrap();
assert_eq!(lid.face_count(), 1);
let edges = lid.edge_count();
assert!(matches!(lid.solid.face_iter().next().unwrap().surface(), mt::Surface::Plane(_)), "tilt {tilt:?}");
let closed = stitch(&[&open, &lid], 0.0).unwrap();
assert!(!closed.is_surface());
let (want, got) = (measure(&solid).unwrap().volume, measure(&closed).unwrap().volume);
eprintln!("rim cut at {tilt:?}: {edges} intersection curves, planar face, volume {got} against {want}");
assert!((got - want).abs() < want * 1e-6, "{got} vs {want}");
}
}
#[test]
fn planar_loops_are_still_one_planar_face() {
let b = crate::box_solid(Vec3::ZERO, Vec3::new(10.0, 10.0, 10.0)).unwrap();
let open = copy_faces(
&b,
&[Vec3::new(5.0, 5.0, 0.0), Vec3::new(5.0, 0.0, 5.0), Vec3::new(10.0, 5.0, 5.0), Vec3::new(5.0, 10.0, 5.0), Vec3::new(0.0, 5.0, 5.0)],
)
.unwrap();
let rim = [Vec3::new(5.0, 0.0, 10.0), Vec3::new(10.0, 5.0, 10.0), Vec3::new(5.0, 10.0, 10.0), Vec3::new(0.0, 5.0, 10.0)];
let lid = patch_edges(&open, &rim).unwrap();
assert_eq!(lid.face_count(), 1);
assert!(matches!(lid.solid.face_iter().next().unwrap().surface(), mt::Surface::Plane(_)));
let closed = stitch(&[&open, &lid], 0.0).unwrap();
assert!((measure(&closed).unwrap().volume - 1000.0).abs() < 1e-9);
}
#[test]
fn open_partial_or_hostile_picks_are_refused() {
let (_, open, rim) = cup(&regular(5, 0.3), Vec2::ZERO);
assert!(patch_edges(&open, &rim[..4]).is_err(), "a loop with a missing edge");
assert!(patch_edges(&open, &[]).is_err());
assert!(patch_edges(&open, &[Vec3::new(f64::NAN, 0.0, 0.0)]).is_err());
assert!(patch_edges(&open, &[Vec3::new(1e300, 0.0, 0.0)]).is_err());
assert!(patch_edges(&open, &vec![rim[0]; 20_000]).is_err());
}
}