bherbruckandClaude Opus 5.5
0670de3f57
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
790 lines
35 KiB
Rust
790 lines
35 KiB
Rust
//! Topology-preserving face offsets for bodies made of planes and cylinders (shells, offset
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//! faces). Each face moves along its outward normal by its own distance: a plane is translated,
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//! a cylinder changes radius about its axis. Every vertex and edge goes to where its faces'
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//! moved surfaces meet; edges are lines or circular arcs. This is exact when the moved
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//! surfaces meet the way the old ones did (prismatic parts, bosses, fillets between walls);
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//! anything else is refused, so callers can fall back.
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use std::collections::HashMap;
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use solvecraft_geom::Vec3;
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use truck_modeling::{self as mt, builder};
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use crate::body::{Body, Solid, from_p3, p3};
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use crate::{KernelError, Result, guard};
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#[derive(Clone, Copy, Debug)]
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enum Surf {
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/// Outward normal and offset: n·x = d.
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Plane { n: Vec3, d: f64 },
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/// Axis point and direction, radius; `convex` when the outward normal points away from
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/// the axis.
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Cylinder { o: Vec3, a: Vec3, r: f64, convex: bool },
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/// Centre and radius; `convex` when the outward normal points away from the centre.
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Sphere { c: Vec3, r: f64, convex: bool },
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/// Apex, unit axis (into the cone, away from the apex) and half-angle; `convex` when the
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/// outward normal points away from the axis.
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Cone { v: Vec3, a: Vec3, half: f64, convex: bool },
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/// Axis point and unit axis, the tube's centre circle (radius `big` at height `h` along the
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/// axis) and the tube radius; `convex` when the outward normal points away from the tube's
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/// centre.
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Torus { o: Vec3, a: Vec3, big: f64, h: f64, r: f64, convex: bool },
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}
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/// The centre of a torus tube nearest `p`.
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fn tube_centre(o: Vec3, a: Vec3, big: f64, h: f64, p: Vec3) -> Option<Vec3> {
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let w = p - o;
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let u = (w - a * w.dot(a)).normalized()?;
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Some(o + a * h + u * big)
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}
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impl Surf {
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/// Outward unit normal of the surface at `p` (on or near it).
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fn normal(&self, p: Vec3) -> Option<Vec3> {
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match *self {
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Surf::Plane { n, .. } => Some(n),
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Surf::Cylinder { o, a, convex, .. } => {
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let v = p - o;
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let radial = (v - a * v.dot(a)).normalized()?;
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Some(if convex { radial } else { -radial })
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}
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Surf::Sphere { c, convex, .. } => {
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let radial = (p - c).normalized()?;
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Some(if convex { radial } else { -radial })
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}
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Surf::Cone { v, a, half, convex } => {
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let w = p - v;
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let q = (w - a * w.dot(a)).normalized()?;
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let n = q * half.cos() - a * half.sin();
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Some(if convex { n } else { -n })
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}
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Surf::Torus { o, a, big, h, convex, .. } => {
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let n = (p - tube_centre(o, a, big, h, p)?).normalized()?;
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Some(if convex { n } else { -n })
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}
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}
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}
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fn moved(&self, s: f64) -> Option<Surf> {
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match *self {
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Surf::Plane { n, d } => Some(Surf::Plane { n, d: d + s }),
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Surf::Cylinder { o, a, r, convex } => {
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let r2 = if convex { r + s } else { r - s };
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(r2 > 1e-9).then_some(Surf::Cylinder { o, a, r: r2, convex })
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}
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Surf::Sphere { c, r, convex } => {
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let r2 = if convex { r + s } else { r - s };
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(r2 > 1e-9).then_some(Surf::Sphere { c, r: r2, convex })
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}
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// Moving a cone along its normal moves its apex along the axis.
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Surf::Cone { v, a, half, convex } => {
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let s = if convex { s } else { -s };
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let sh = half.sin();
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(sh > 1e-9).then_some(Surf::Cone { v: v - a * (s / sh), a, half, convex })
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}
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Surf::Torus { o, a, big, h, r, convex } => {
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let r2 = if convex { r + s } else { r - s };
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(r2 > 1e-9).then_some(Surf::Torus { o, a, big, h, r: r2, convex })
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}
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}
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}
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fn dist(&self, p: Vec3) -> f64 {
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match *self {
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Surf::Plane { n, d } => n.dot(p) - d,
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Surf::Cylinder { o, a, r, .. } => {
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let v = p - o;
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(v - a * v.dot(a)).len() - r
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}
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Surf::Sphere { c, r, .. } => p.dist(c) - r,
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Surf::Cone { v, a, half, .. } => {
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let w = p - v;
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let h = w.dot(a);
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(w - a * h).len() * half.cos() - h * half.sin()
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}
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Surf::Torus { o, a, big, h, r, .. } => tube_centre(o, a, big, h, p).map(|c| p.dist(c) - r).unwrap_or(f64::INFINITY),
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}
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}
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/// The affine map taking this surface onto `to` (same kind, same axis).
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fn map_to(&self, to: &Surf) -> Option<mt::Matrix4> {
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match (*self, *to) {
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(Surf::Sphere { c, r, .. }, Surf::Sphere { r: r2, .. }) => {
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let k = r2 / r;
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let t = c * (1.0 - k);
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Some(mt::Matrix4::from_translation(mt::Vector3::new(t.x, t.y, t.z)) * mt::Matrix4::from_scale(k))
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}
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(Surf::Cone { v, .. }, Surf::Cone { v: v2, .. }) => {
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let t = v2 - v;
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Some(mt::Matrix4::from_translation(mt::Vector3::new(t.x, t.y, t.z)))
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}
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(Surf::Plane { n, d }, Surf::Plane { d: d2, .. }) => {
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let t = n * (d2 - d);
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Some(mt::Matrix4::from_translation(mt::Vector3::new(t.x, t.y, t.z)))
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}
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(Surf::Cylinder { o, a, r, .. }, Surf::Cylinder { r: r2, .. }) => {
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// Scale by k across the axis: x ↦ o + k (x − o) + (1 − k) a a·(x − o).
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let k = r2 / r;
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let m = |i: usize, j: usize| {
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let (ai, aj) = ([a.x, a.y, a.z][i], [a.x, a.y, a.z][j]);
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(if i == j { k } else { 0.0 }) + (1.0 - k) * ai * aj
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};
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let lin = [[m(0, 0), m(0, 1), m(0, 2)], [m(1, 0), m(1, 1), m(1, 2)], [m(2, 0), m(2, 1), m(2, 2)]];
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let ov = [o.x, o.y, o.z];
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let t: Vec<f64> = (0..3).map(|i| ov[i] - (0..3).map(|j| lin[i][j] * ov[j]).sum::<f64>()).collect();
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// Column-major.
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Some(mt::Matrix4::new(
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lin[0][0],
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lin[1][0],
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lin[2][0],
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0.0,
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lin[0][1],
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lin[1][1],
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lin[2][1],
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0.0,
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lin[0][2],
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lin[1][2],
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lin[2][2],
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0.0,
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*t.first()?,
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*t.get(1)?,
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*t.get(2)?,
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1.0,
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))
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}
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_ => None,
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}
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}
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}
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fn fail(m: &str) -> KernelError {
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KernelError::Failed(format!("offset: {m}"))
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}
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/// Points and outward normals sampled over a face (boundary and a grid inside its
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/// parameter box).
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fn samples(f: &mt::Face) -> Vec<(Vec3, Vec3)> {
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use mt::{BoundedCurve, ParametricCurve, ParametricSurface, ParametricSurface3D, SearchNearestParameter};
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let surf = f.oriented_surface();
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let mut uv: Vec<(f64, f64)> = Vec::new();
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for w in f.boundaries() {
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for e in w.edge_iter() {
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let c = e.oriented_curve();
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let (t0, t1) = c.range_tuple();
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for k in 0..5 {
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// The previous point's parameters as a hint, unless that lands elsewhere (a
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// singular point such as a pole holds the search).
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let q = c.subs(t0 + (t1 - t0) * k as f64 / 5.0);
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let near = |x: (f64, f64)| from_p3(surf.subs(x.0, x.1)).dist(from_p3(q)) < 1e-6 * (1.0 + from_p3(q).len());
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let found = surf
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.search_nearest_parameter(q, uv.last().copied(), 50)
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.filter(|x| near(*x))
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.or_else(|| surf.search_nearest_parameter(q, None, 100).filter(|x| near(*x)));
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if let Some(x) = found {
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uv.push(x);
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}
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}
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}
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}
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let Some(&(u0, v0)) = uv.first() else { return Vec::new() };
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let (mut lo, mut hi) = ((u0, v0), (u0, v0));
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for (u, v) in &uv {
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lo = (lo.0.min(*u), lo.1.min(*v));
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hi = (hi.0.max(*u), hi.1.max(*v));
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}
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for i in 0..=4 {
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for j in 0..=4 {
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uv.push((lo.0 + (hi.0 - lo.0) * i as f64 / 4.0, lo.1 + (hi.1 - lo.1) * j as f64 / 4.0));
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}
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}
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// Parameter steps for checking that the normal is steady (not at a cone's apex).
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let (du, dv) = (((hi.0 - lo.0) * 1e-6).max(1e-9), ((hi.1 - lo.1) * 1e-6).max(1e-9));
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let nrm = |u: f64, v: f64| {
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let n = surf.normal(u, v);
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Vec3::new(n.x, n.y, n.z).normalized()
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};
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uv.iter()
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.filter_map(|(u, v)| {
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let n = nrm(*u, *v)?;
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let steady =
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[nrm(*u + du, *v), nrm(*u - du, *v), nrm(*u, *v + dv), nrm(*u, *v - dv)].iter().all(|m| m.is_some_and(|m| m.dot(n) > 1.0 - 1e-6));
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steady.then(|| (from_p3(surf.subs(*u, *v)), n))
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})
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.collect()
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}
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/// What surface a face lies on (planes and cylinders only).
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fn surf_of(f: &mt::Face, tol: f64) -> Option<Surf> {
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if let mt::Surface::Plane(pl) = f.oriented_surface() {
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let n = pl.normal();
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let n = Vec3::new(n.x, n.y, n.z).normalized()?;
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return Some(Surf::Plane { n, d: n.dot(from_p3(pl.origin())) });
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}
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let s = samples(f);
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if let Some(t) = torus_of(f, &s, tol) {
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return Some(t);
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}
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let (p0, n0) = *s.first()?;
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// The normal most square to the first (a half cylinder's two ends are opposite).
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let far = s.iter().map(|x| x.1).min_by(|a, b| a.dot(n0).abs().total_cmp(&b.dot(n0).abs()))?;
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let Some(a) = n0.cross(far).normalized() else { return sphere_or_cone(&s, tol) };
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if s.iter().any(|(_, n)| n.dot(a).abs() > 1e-6) {
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return sphere_or_cone(&s, tol);
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}
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// The axis: where the normal lines through two samples meet (seen along a).
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let (p1, n1) = *s.iter().min_by(|x, y| x.1.dot(n0).abs().total_cmp(&y.1.dot(n0).abs()))?;
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// p0 + t0 n0 = p1 + t1 n1 (projected): solve in the plane ⟂ a.
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let w = p1 - p0;
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let c = n0.dot(n1);
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let den = 1.0 - c * c;
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if den.abs() < 1e-9 {
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return None;
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}
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let t0 = (w.dot(n0) - c * w.dot(n1)) / den;
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let o = p0 + n0 * t0;
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let o = o - a * (o - p0).dot(a);
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let r = t0.abs();
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// Outward normal away from the axis: p = o + r n (t0 < 0 means o = p − r n).
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let convex = t0 < 0.0;
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let cyl = Surf::Cylinder { o, a, r, convex };
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let ok = s.iter().all(|(p, n)| cyl.dist(*p).abs() < tol && cyl.normal(*p).is_some_and(|m| m.dot(*n) > 1.0 - 1e-6));
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ok.then_some(cyl)
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}
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/// A torus: a surface of revolution whose normals (in the meridian plane) all point from one
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/// circle, the tube's centre, at one distance.
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fn torus_of(f: &mt::Face, s: &[(Vec3, Vec3)], tol: f64) -> Option<Surf> {
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let mt::Surface::RevolutedCurve(rc) = f.surface() else { return None };
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if *rc.transform() != <mt::Matrix4 as mt::One>::one() {
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return None;
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}
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let (o, ax) = (from_p3(rc.entity().origin()), rc.entity().axis());
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let a = Vec3::new(ax.x, ax.y, ax.z).normalized()?;
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// Meridian coordinates: ρ − r n_ρ = R and h − r n_h = h0 for every sample, least squares
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// in (R, h0, r).
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let mut m = [[0.0f64; 3]; 3];
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let mut rhs = [0.0f64; 3];
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for (p, n) in s {
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let w = *p - o;
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let hh = w.dot(a);
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let radial = w - a * hh;
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let u = radial.normalized()?;
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for (row, val) in [([1.0, 0.0, n.dot(u)], radial.len()), ([0.0, 1.0, n.dot(a)], hh)] {
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for i in 0..3 {
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for j in 0..3 {
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m[i][j] += row[i] * row[j];
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}
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rhs[i] += row[i] * val;
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}
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}
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}
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let x = crate::polyhedron::solve3_pub(m, rhs)?;
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let (big, h, r) = (x[0], x[1], x[2]);
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if !(big > 1e-9 && r.abs() > 1e-9 && r.abs() < big) {
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return None;
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}
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let t = Surf::Torus { o, a, big, h, r: r.abs(), convex: r > 0.0 };
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s.iter().all(|(p, n)| t.dist(*p).abs() < tol && t.normal(*p).is_some_and(|m| m.dot(*n) > 1.0 - 1e-6)).then_some(t)
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}
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/// A sphere (normal lines all through one point) or a cone (tangent planes all through one
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/// point, normals at one angle to an axis) through the samples.
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fn sphere_or_cone(s: &[(Vec3, Vec3)], tol: f64) -> Option<Surf> {
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// Least squares point nearest all the normal lines: Σ (I − n nᵀ) x = Σ (I − n nᵀ) p.
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let mut m = [[0.0f64; 3]; 3];
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let mut r = [0.0f64; 3];
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for (p, n) in s {
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let nv = [n.x, n.y, n.z];
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let pv = [p.x, p.y, p.z];
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for i in 0..3 {
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for j in 0..3 {
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let a = (if i == j { 1.0 } else { 0.0 }) - nv[i] * nv[j];
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m[i][j] += a;
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r[i] += a * pv[j];
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}
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}
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}
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if let Some(x) = crate::polyhedron::solve3_pub(m, r) {
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let c = Vec3::new(x[0], x[1], x[2]);
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let (p0, n0) = *s.first()?;
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let rad = p0.dist(c);
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let convex = (p0 - c).dot(n0) > 0.0;
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let sp = Surf::Sphere { c, r: rad, convex };
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if rad > tol && s.iter().all(|(p, n)| sp.dist(*p).abs() < tol && sp.normal(*p).is_some_and(|q| q.dot(*n) > 1.0 - 1e-6)) {
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return Some(sp);
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}
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}
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// Cone: the apex lies on every tangent plane, n·(v − p) = 0.
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let mut m = [[0.0f64; 3]; 3];
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let mut r = [0.0f64; 3];
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for (p, n) in s {
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let nv = [n.x, n.y, n.z];
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let k = n.dot(*p);
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for i in 0..3 {
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for j in 0..3 {
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m[i][j] += nv[i] * nv[j];
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}
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r[i] += nv[i] * k;
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}
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}
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let x = crate::polyhedron::solve3_pub(m, r)?;
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let v = Vec3::new(x[0], x[1], x[2]);
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// Axis: from the apex toward the samples' centroid (the cone opens that way).
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let cen = s.iter().fold(Vec3::ZERO, |acc, (p, _)| acc + *p) * (1.0 / s.len() as f64);
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// Normals make a constant angle with the axis: fit it from three spread normals.
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let n0 = s.first()?.1;
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let n1 = s.iter().map(|x| x.1).max_by(|a, b| (*a - n0).len().total_cmp(&(*b - n0).len()))?;
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let n2 = s.iter().map(|x| x.1).max_by(|a, b| (*a - n0).cross(n1 - n0).len().total_cmp(&(*b - n0).cross(n1 - n0).len()))?;
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let mut a = (n1 - n0).cross(n2 - n0).normalized()?;
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if a.dot(cen - v) < 0.0 {
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a = -a;
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}
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let half = n0.dot(a).abs().clamp(0.0, 1.0).asin();
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if !(half > 1e-3 && half < std::f64::consts::FRAC_PI_2 - 1e-3) {
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return None;
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}
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let (p0, n0) = *s.first()?;
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let q = {
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let w = p0 - v;
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(w - a * w.dot(a)).normalized()?
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};
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let convex = n0.dot(q) > 0.0;
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let cone = Surf::Cone { v, a, half, convex };
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s.iter().all(|(p, n)| cone.dist(*p).abs() < tol && cone.normal(*p).is_some_and(|m| m.dot(*n) > 1.0 - 1e-6)).then_some(cone)
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}
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/// Move `p` (on all of `old`) onto the moved surfaces `new`: the smallest displacement δ with
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/// n_i · δ = s_i for each face's normal n_i at p, then checked against the moved surfaces.
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fn move_point(p: Vec3, old: &[Surf], shifts: &[f64], new: &[Surf], tol: f64) -> Option<Vec3> {
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let ns: Vec<Vec3> = old.iter().map(|sf| sf.normal(p)).collect::<Option<_>>()?;
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// Orthonormal basis of the normals' span (tangent faces share a normal).
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let mut basis: Vec<Vec3> = Vec::new();
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for n in &ns {
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let mut v = *n;
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for e in &basis {
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v = v - *e * v.dot(*e);
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}
|
||
if let Some(u) = v.normalized().filter(|_| v.len() > 1e-6) {
|
||
basis.push(u);
|
||
}
|
||
}
|
||
// Least squares in the span: rows n_i · e_k, right-hand sides s_i.
|
||
let r = basis.len();
|
||
let mut m = [[0.0f64; 3]; 3];
|
||
let mut rhs = [0.0f64; 3];
|
||
for (n, s) in ns.iter().zip(shifts) {
|
||
let row: Vec<f64> = basis.iter().map(|e| n.dot(*e)).collect();
|
||
for i in 0..r {
|
||
for j in 0..r {
|
||
m[i][j] += row[i] * row[j];
|
||
}
|
||
rhs[i] += row[i] * s;
|
||
}
|
||
}
|
||
// Pad unused dimensions with the identity.
|
||
for (i, row) in m.iter_mut().enumerate().skip(r) {
|
||
row[i] = 1.0;
|
||
}
|
||
let c = crate::polyhedron::solve3_pub(m, rhs)?;
|
||
let mut q = p;
|
||
for (k, e) in basis.iter().enumerate() {
|
||
q += *e * c[k];
|
||
}
|
||
new.iter().all(|sf| sf.dist(q).abs() < tol).then_some(q)
|
||
}
|
||
|
||
/// A line or circular arc through an edge (by samples): `None` for other curves.
|
||
fn arc_mid(e: &mt::Edge, tol: f64) -> Option<Option<Vec3>> {
|
||
use mt::{BoundedCurve, ParametricCurve};
|
||
let c = e.curve();
|
||
let (t0, t1) = c.range_tuple();
|
||
let pts: Vec<Vec3> = (0..=16).map(|k| from_p3(c.subs(t0 + (t1 - t0) * k as f64 / 16.0))).collect();
|
||
let (a, b, m) = (*pts.first()?, *pts.last()?, *pts.get(8)?);
|
||
if a.dist(b) < tol {
|
||
return None;
|
||
}
|
||
if pts.iter().all(|p| p.dist_to_segment(a, b) < tol) {
|
||
return Some(None);
|
||
}
|
||
let (u, v) = (b - a, m - a);
|
||
let w = u.cross(v);
|
||
let d = 2.0 * w.len2();
|
||
if d < 1e-300 {
|
||
return None;
|
||
}
|
||
let centre = a + (v.cross(w) * u.len2() + w.cross(u) * v.len2()) * (1.0 / d);
|
||
let r = centre.dist(a);
|
||
pts.iter().all(|p| (p.dist(centre) - r).abs() < tol && (*p - centre).dot(w.normalized().unwrap_or(Vec3::Z)).abs() < tol).then_some(Some(m))
|
||
}
|
||
|
||
/// The body with each face moved along its outward normal by `shift(face index, normal at a
|
||
/// face point)`, keeping the topology. Faces must be planes or cylinders.
|
||
pub(crate) fn offset_body(b: &Body, shift: impl Fn(usize, Vec3) -> f64) -> Result<Body> {
|
||
let faces: Vec<mt::Face> = b.solid.face_iter().cloned().collect();
|
||
let size = b.size();
|
||
let tol = (size * 1e-7).max(1e-9);
|
||
let mut old = Vec::with_capacity(faces.len());
|
||
let mut new = Vec::with_capacity(faces.len());
|
||
let mut shifts = Vec::with_capacity(faces.len());
|
||
for (i, f) in faces.iter().enumerate() {
|
||
let sf = surf_of(f, tol * 100.0).ok_or_else(|| fail("only bodies with planes, cylinders, cones, spheres and tori"))?;
|
||
let n = match sf {
|
||
Surf::Plane { n, .. } => n,
|
||
Surf::Cylinder { a, .. } | Surf::Cone { a, .. } | Surf::Torus { a, .. } => a.any_perp(),
|
||
Surf::Sphere { .. } => Vec3::Z,
|
||
};
|
||
let s = shift(i, n);
|
||
old.push(sf);
|
||
new.push(sf.moved(s).ok_or_else(|| fail("a cylinder shrinks to nothing"))?);
|
||
shifts.push(s);
|
||
}
|
||
let pick = |ids: &[usize]| -> (Vec<Surf>, Vec<f64>, Vec<Surf>) {
|
||
(
|
||
ids.iter().filter_map(|i| old.get(*i).copied()).collect(),
|
||
ids.iter().filter_map(|i| shifts.get(*i).copied()).collect(),
|
||
ids.iter().filter_map(|i| new.get(*i).copied()).collect(),
|
||
)
|
||
};
|
||
// Vertex → its faces; edge → its faces.
|
||
let mut vfaces: HashMap<mt::VertexID, Vec<usize>> = HashMap::new();
|
||
let mut efaces: HashMap<mt::EdgeID, Vec<usize>> = HashMap::new();
|
||
for (i, f) in faces.iter().enumerate() {
|
||
for v in f.vertex_iter() {
|
||
let e = vfaces.entry(v.id()).or_default();
|
||
if !e.contains(&i) {
|
||
e.push(i);
|
||
}
|
||
}
|
||
for ed in f.edge_iter() {
|
||
let e = efaces.entry(ed.id()).or_default();
|
||
if !e.contains(&i) {
|
||
e.push(i);
|
||
}
|
||
}
|
||
}
|
||
let mut newpos: HashMap<mt::VertexID, Vec3> = HashMap::new();
|
||
for v in b.solid.vertex_iter() {
|
||
let fs = vfaces.get(&v.id()).ok_or_else(|| fail("vertex"))?;
|
||
let (o, s, n) = pick(fs);
|
||
let p = from_p3(v.point());
|
||
// A cone's apex goes with the cone (its normal is not defined there).
|
||
let apex = o.iter().zip(&n).find_map(|(a, b)| match (a, b) {
|
||
(Surf::Cone { v: va, .. }, Surf::Cone { v: vb, .. }) if va.dist(p) < size * 1e-6 => Some(*vb),
|
||
_ => None,
|
||
});
|
||
let q = match apex {
|
||
Some(q) if n.iter().all(|sf| sf.dist(q).abs() < size * 1e-6) => q,
|
||
_ => move_point(p, &o, &s, &n, size * 1e-6).ok_or_else(|| fail("a corner whose faces don't meet the same way after the move"))?,
|
||
};
|
||
newpos.insert(v.id(), q);
|
||
}
|
||
guard("offset", || {
|
||
let verts: HashMap<mt::VertexID, mt::Vertex> = newpos.iter().map(|(k, p)| (*k, builder::vertex(p3(*p)))).collect();
|
||
let mut edges: HashMap<mt::EdgeID, mt::Edge> = HashMap::new();
|
||
for e in b.solid.edge_iter() {
|
||
if edges.contains_key(&e.id()) {
|
||
continue;
|
||
}
|
||
let (Some(a), Some(c)) = (verts.get(&e.absolute_front().id()), verts.get(&e.absolute_back().id())) else { return Err(fail("edge")) };
|
||
if from_p3(a.point()).dist(from_p3(c.point())) < size * 1e-9 {
|
||
return Err(fail("an edge vanishes (the offset is too large)"));
|
||
}
|
||
let kind = arc_mid(&e, size * 1e-6).ok_or_else(|| fail("edges must be lines or arcs"))?;
|
||
let ne = match kind {
|
||
None => builder::line(a, c),
|
||
Some(m) => {
|
||
let fs = efaces.get(&e.id()).ok_or_else(|| fail("edge faces"))?;
|
||
let (o, s, n) = pick(fs);
|
||
let m2 =
|
||
move_point(m, &o, &s, &n, size * 1e-6).ok_or_else(|| fail("an edge whose faces don't meet the same way after the move"))?;
|
||
builder::circle_arc(a, c, p3(m2))
|
||
}
|
||
};
|
||
edges.insert(e.id(), ne);
|
||
}
|
||
let mut out = Vec::new();
|
||
for (i, f) in faces.iter().enumerate() {
|
||
let wires: Vec<mt::Wire> = f
|
||
.absolute_boundaries()
|
||
.iter()
|
||
.map(|w| {
|
||
w.edge_iter()
|
||
.filter_map(|e| edges.get(&e.id()).map(|ne| if e.front() == e.absolute_front() { ne.clone() } else { ne.inverse() }))
|
||
.collect::<Vec<_>>()
|
||
.into()
|
||
})
|
||
.collect();
|
||
let (Some(o), Some(n)) = (old.get(i), new.get(i)) else { return Err(fail("face")) };
|
||
let surface = match (o.map_to(n), *o, *n) {
|
||
(Some(mat), _, _) => mt::Transformed::transformed(&f.surface(), mat),
|
||
// A torus: its tube's circle scaled about the tube's centre, revolved again.
|
||
(None, Surf::Torus { o: to, a, big, h, r, .. }, Surf::Torus { r: r2, .. }) => {
|
||
use mt::{BoundedCurve, ParametricCurve};
|
||
let mt::Surface::RevolutedCurve(rc) = f.surface() else { return Err(fail("torus surface")) };
|
||
let curve = rc.entity().entity_curve().clone();
|
||
let (t0, t1) = curve.range_tuple();
|
||
let q = from_p3(curve.subs((t0 + t1) / 2.0));
|
||
let c = tube_centre(to, a, big, h, q).ok_or_else(|| fail("torus"))?;
|
||
let k = r2 / r;
|
||
let t = c * (1.0 - k);
|
||
let mat = mt::Matrix4::from_translation(mt::Vector3::new(t.x, t.y, t.z)) * mt::Matrix4::from_scale(k);
|
||
let moved = mt::Transformed::transformed(&curve, mat);
|
||
let mut p = mt::Processor::new(mt::RevolutedCurve::by_revolution(moved, rc.entity().origin(), rc.entity().axis()));
|
||
if !rc.orientation() {
|
||
mt::Invertible::invert(&mut p);
|
||
}
|
||
mt::Surface::RevolutedCurve(p)
|
||
}
|
||
_ => return Err(fail("surface")),
|
||
};
|
||
let mut nf = mt::Face::try_new(wires, surface).map_err(|e| fail(&e.to_string()))?;
|
||
if !f.orientation() {
|
||
nf.invert();
|
||
}
|
||
out.push(nf);
|
||
}
|
||
let shell: mt::Shell = out.into();
|
||
let solid = Solid::try_new(vec![shell]).map_err(|e| fail(&e.to_string()))?;
|
||
Body::new(solid)
|
||
})
|
||
}
|
||
|
||
/// Draft walls parallel to `pull` (planes, and cylinders about axes along `pull`) by `angle`
|
||
/// about their line on the neutral plane: at height h along `pull` a wall moves along its
|
||
/// outward normal by −h·tan(angle), so planes tilt and cylinders become cones. The other
|
||
/// faces must be caps square to `pull`; the topology is kept.
|
||
pub(crate) fn draft_walls(b: &Body, chosen: &[usize], neutral: &solvecraft_geom::Plane, pull: Vec3, angle: f64) -> Result<Body> {
|
||
let faces: Vec<mt::Face> = b.solid.face_iter().cloned().collect();
|
||
let size = b.size();
|
||
let tol = (size * 1e-7).max(1e-9);
|
||
let nn = neutral.normal();
|
||
let den = pull.dot(nn);
|
||
if den.abs() < 1e-9 {
|
||
return Err(fail("the neutral plane is parallel to the pull direction"));
|
||
}
|
||
let height = |p: Vec3| (p - neutral.origin).dot(nn) / den;
|
||
let tan = angle.tan();
|
||
let mut old = Vec::with_capacity(faces.len());
|
||
for (i, f) in faces.iter().enumerate() {
|
||
let sf = surf_of(f, tol * 100.0).ok_or_else(|| fail("draft: only bodies with planar and cylindrical faces"))?;
|
||
let wall = match sf {
|
||
Surf::Plane { n, .. } => n.dot(pull).abs() < 1e-9,
|
||
Surf::Cylinder { a, .. } => a.dot(pull).abs() > 1.0 - 1e-9,
|
||
Surf::Sphere { .. } | Surf::Cone { .. } | Surf::Torus { .. } => false,
|
||
};
|
||
let cap = matches!(sf, Surf::Plane { n, .. } if n.dot(pull).abs() > 1.0 - 1e-9);
|
||
if chosen.contains(&i) && !wall {
|
||
return Err(fail("draft: a chosen face isn't parallel to the pull direction"));
|
||
}
|
||
if !chosen.contains(&i) && !cap && !wall {
|
||
return Err(fail("draft: faces next to the drafted walls must be square to the pull direction"));
|
||
}
|
||
old.push(sf);
|
||
}
|
||
// Shifts and moved surfaces at a height.
|
||
let at = |ids: &[usize], h: f64| -> Option<(Vec<Surf>, Vec<f64>, Vec<Surf>)> {
|
||
let mut o = Vec::new();
|
||
let mut s = Vec::new();
|
||
let mut n = Vec::new();
|
||
for i in ids {
|
||
let sf = *old.get(*i)?;
|
||
let sh = if chosen.contains(i) { -h * tan } else { 0.0 };
|
||
o.push(sf);
|
||
s.push(sh);
|
||
n.push(sf.moved(sh)?);
|
||
}
|
||
Some((o, s, n))
|
||
};
|
||
let mut vfaces: HashMap<mt::VertexID, Vec<usize>> = HashMap::new();
|
||
let mut efaces: HashMap<mt::EdgeID, Vec<usize>> = HashMap::new();
|
||
for (i, f) in faces.iter().enumerate() {
|
||
for v in f.vertex_iter() {
|
||
let e = vfaces.entry(v.id()).or_default();
|
||
if !e.contains(&i) {
|
||
e.push(i);
|
||
}
|
||
}
|
||
for ed in f.edge_iter() {
|
||
let e = efaces.entry(ed.id()).or_default();
|
||
if !e.contains(&i) {
|
||
e.push(i);
|
||
}
|
||
}
|
||
}
|
||
let mut newpos: HashMap<mt::VertexID, Vec3> = HashMap::new();
|
||
for v in b.solid.vertex_iter() {
|
||
let p = from_p3(v.point());
|
||
let fs = vfaces.get(&v.id()).ok_or_else(|| fail("vertex"))?;
|
||
let (o, s, n) = at(fs, height(p)).ok_or_else(|| fail("draft: a wall shrinks to nothing"))?;
|
||
let q = move_point(p, &o, &s, &n, size * 1e-6).ok_or_else(|| fail("draft: a corner whose faces don't meet the same way after the draft"))?;
|
||
newpos.insert(v.id(), q);
|
||
}
|
||
// New surfaces for the drafted walls: planes through their hinge line, cylinders → cones.
|
||
let mut surfaces: Vec<Option<mt::Surface>> = vec![None; faces.len()];
|
||
for (i, sf) in old.iter().enumerate() {
|
||
if !chosen.contains(&i) {
|
||
continue;
|
||
}
|
||
let surface = match *sf {
|
||
Surf::Plane { n, d } => {
|
||
let n2 = (n * angle.cos() + pull * angle.sin()).normalized().ok_or_else(|| fail("draft"))?;
|
||
// A point of the old plane on the neutral plane: the hinge.
|
||
let o = neutral.intersect_ray(n * d, pull).ok_or_else(|| fail("draft: hinge"))?;
|
||
let u = n2.cross(pull).normalized().ok_or_else(|| fail("draft"))?;
|
||
let w = n2.cross(u);
|
||
mt::Surface::Plane(mt::Plane::new(p3(o), p3(o + u), p3(o + w)))
|
||
}
|
||
Surf::Cylinder { o, a, r, convex } => {
|
||
// Generator: the wall at two heights along one radial direction.
|
||
let u = a.any_perp();
|
||
// Over the face's heights (and a little beyond), short of the apex.
|
||
let hs: Vec<f64> = faces.get(i).map(|f| f.vertex_iter().map(|v| height(from_p3(v.point()))).collect()).unwrap_or_default();
|
||
let (lo, hi) = hs.iter().fold((f64::INFINITY, f64::NEG_INFINITY), |m, h| (m.0.min(*h), m.1.max(*h)));
|
||
if !(lo.is_finite() && hi.is_finite()) {
|
||
return Err(fail("draft: a wall without corners"));
|
||
}
|
||
let pad = (hi - lo).max(size * 1e-3) * 0.25;
|
||
let (mut h0, mut h1) = (lo - pad, hi + pad);
|
||
// Keep the radius positive along the generator.
|
||
let r_at = |h: f64| if convex { r - h * tan } else { r + h * tan };
|
||
for h in [&mut h0, &mut h1] {
|
||
if r_at(*h) <= r * 1e-3 {
|
||
*h = if (*h - lo).abs() < (*h - hi).abs() { lo } else { hi };
|
||
}
|
||
}
|
||
let base = |h: f64| {
|
||
let rr = if convex { r - h * tan } else { r + h * tan };
|
||
o + pull * (h - height(o)) + u * rr
|
||
};
|
||
let (pa, pb) = (base(h0), base(h1));
|
||
let line = mt::Curve::Line(mt::Line(p3(pa), p3(pb)));
|
||
let rc = mt::RevolutedCurve::by_revolution(line, p3(o), mt::Vector3::new(a.x, a.y, a.z));
|
||
mt::Surface::RevolutedCurve(mt::Processor::new(rc))
|
||
}
|
||
Surf::Sphere { .. } | Surf::Cone { .. } | Surf::Torus { .. } => {
|
||
return Err(fail("draft: only planes and cylinders along the pull can be drafted"));
|
||
}
|
||
};
|
||
if let Some(slot) = surfaces.get_mut(i) {
|
||
*slot = Some(surface);
|
||
}
|
||
}
|
||
guard("draft", || {
|
||
let verts: HashMap<mt::VertexID, mt::Vertex> = newpos.iter().map(|(k, p)| (*k, builder::vertex(p3(*p)))).collect();
|
||
let mut edges: HashMap<mt::EdgeID, mt::Edge> = HashMap::new();
|
||
for e in b.solid.edge_iter() {
|
||
if edges.contains_key(&e.id()) {
|
||
continue;
|
||
}
|
||
let (Some(a), Some(c)) = (verts.get(&e.absolute_front().id()), verts.get(&e.absolute_back().id())) else { return Err(fail("edge")) };
|
||
let kind = arc_mid(&e, size * 1e-6).ok_or_else(|| fail("draft: edges must be lines or arcs"))?;
|
||
let ne = match kind {
|
||
None => builder::line(a, c),
|
||
Some(m) => {
|
||
let fs = efaces.get(&e.id()).ok_or_else(|| fail("edge faces"))?;
|
||
let (o, s, n) = at(fs, height(m)).ok_or_else(|| fail("draft"))?;
|
||
let m2 = move_point(m, &o, &s, &n, size * 1e-6).ok_or_else(|| fail("draft: an arc that can't follow its faces"))?;
|
||
builder::circle_arc(a, c, p3(m2))
|
||
}
|
||
};
|
||
edges.insert(e.id(), ne);
|
||
}
|
||
let mut out = Vec::new();
|
||
for (i, f) in faces.iter().enumerate() {
|
||
let wires: Vec<mt::Wire> = f
|
||
.boundaries()
|
||
.iter()
|
||
.map(|w| {
|
||
w.edge_iter()
|
||
.filter_map(|e| edges.get(&e.id()).map(|ne| if e.front() == e.absolute_front() { ne.clone() } else { ne.inverse() }))
|
||
.collect::<Vec<_>>()
|
||
.into()
|
||
})
|
||
.collect();
|
||
let nf = match surfaces.get(i).cloned().flatten() {
|
||
Some(mut surface) => {
|
||
// Outward like the old face (checked at a boundary point).
|
||
let probe = f.boundaries().first().and_then(|w| w.vertex_iter().next()).map(|v| from_p3(v.point()));
|
||
let want = probe.and_then(|p| old.get(i).and_then(|s| s.normal(p)));
|
||
if let (Some(p), Some(want)) = (probe, want) {
|
||
use mt::{ParametricSurface3D, SearchNearestParameter};
|
||
if let Some((u, v)) = surface.search_nearest_parameter(p3(p), None, 100) {
|
||
let nn = surface.normal(u, v);
|
||
if Vec3::new(nn.x, nn.y, nn.z).dot(want) < 0.0 {
|
||
surface = mt::Invertible::inverse(&surface);
|
||
}
|
||
}
|
||
}
|
||
mt::Face::try_new(wires, surface).map_err(|e| fail(&e.to_string()))?
|
||
}
|
||
None => {
|
||
// Unchanged surface: rebuild on the oriented boundary.
|
||
let mut nf = mt::Face::try_new(
|
||
f.absolute_boundaries()
|
||
.iter()
|
||
.map(|w| {
|
||
w.edge_iter()
|
||
.filter_map(|e| {
|
||
edges.get(&e.id()).map(|ne| if e.front() == e.absolute_front() { ne.clone() } else { ne.inverse() })
|
||
})
|
||
.collect::<Vec<_>>()
|
||
.into()
|
||
})
|
||
.collect(),
|
||
f.surface(),
|
||
)
|
||
.map_err(|e| fail(&e.to_string()))?;
|
||
if !f.orientation() {
|
||
nf.invert();
|
||
}
|
||
nf
|
||
}
|
||
};
|
||
out.push(nf);
|
||
}
|
||
let shell: mt::Shell = out.into();
|
||
let solid = Solid::try_new(vec![shell]).map_err(|e| fail(&e.to_string()))?;
|
||
Body::new(solid)
|
||
})
|
||
}
|
||
|
||
/// The chosen faces and every face on the same surface joined to them (the halves of a hole's
|
||
/// wall), as face indices.
|
||
pub(crate) fn with_same_surface(b: &Body, chosen: &[usize]) -> Vec<usize> {
|
||
let faces: Vec<mt::Face> = b.solid.face_iter().cloned().collect();
|
||
let size = b.size();
|
||
let tol = (size * 1e-7).max(1e-9) * 100.0;
|
||
let surfs: Vec<Option<Surf>> = faces.iter().map(|f| surf_of(f, tol)).collect();
|
||
let same = |x: &Surf, y: &Surf| match (*x, *y) {
|
||
(Surf::Plane { n, d }, Surf::Plane { n: m, d: e }) => n.dot(m) > 1.0 - 1e-9 && (d - e).abs() < tol,
|
||
(Surf::Cylinder { o, a, r, convex }, Surf::Cylinder { o: o2, a: a2, r: r2, convex: c2 }) => {
|
||
a.dot(a2).abs() > 1.0 - 1e-9 && (r - r2).abs() < tol && convex == c2 && { (o2 - o - a * (o2 - o).dot(a)).len() < tol }
|
||
}
|
||
(Surf::Sphere { c, r, convex }, Surf::Sphere { c: c2, r: r2, convex: k2 }) => c.dist(c2) < tol && (r - r2).abs() < tol && convex == k2,
|
||
(Surf::Cone { v, a, half, convex }, Surf::Cone { v: v2, a: a2, half: h2, convex: k2 }) => {
|
||
v.dist(v2) < tol && a.dot(a2) > 1.0 - 1e-9 && (half - h2).abs() < 1e-9 && convex == k2
|
||
}
|
||
(Surf::Torus { o, a, big, h, r, convex }, Surf::Torus { o: o2, a: a2, big: b2, h: h2, r: r2, convex: k2 }) => {
|
||
(o + a * h).dist(o2 + a2 * h2) < tol && a.dot(a2).abs() > 1.0 - 1e-9 && (big - b2).abs() < tol && (r - r2).abs() < tol && convex == k2
|
||
}
|
||
_ => false,
|
||
};
|
||
let mut out: Vec<usize> = chosen.to_vec();
|
||
let mut grew = true;
|
||
while grew {
|
||
grew = false;
|
||
for (i, f) in faces.iter().enumerate() {
|
||
if out.contains(&i) {
|
||
continue;
|
||
}
|
||
let Some(Some(si)) = surfs.get(i) else { continue };
|
||
let joins = out.iter().any(|j| {
|
||
surfs.get(*j).and_then(|x| x.as_ref()).is_some_and(|sj| same(si, sj))
|
||
&& faces.get(*j).is_some_and(|g| g.edge_iter().any(|e| f.edge_iter().any(|x| x.id() == e.id())))
|
||
});
|
||
if joins {
|
||
out.push(i);
|
||
grew = true;
|
||
}
|
||
}
|
||
}
|
||
out
|
||
}
|