feat(view): 꺾인 코핑의 코핑 철근을 3D로 그린다

꺾인 코핑은 코핑 철근을 그리지 않았다. 다주형은 접힌 조각(pieces)을 각 구간 좌표로 그리고, T형은 같은
접기(coping-fold.ts)로 편 좌표 철근을 미터점에서 꺾어 그린다.

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

src/view/rebar3d.ts

@@ -7,6 +7,7 @@ import { sideRowLevels } from '../core/coping-geom';
 import { columnRebar, columnInputFor } from '../core/rebar/column';
 import { castRebarLayout } from '../core/rebar/cast-layout';
 import { multicolCopingBars } from '../core/rebar/multicol-coping';
+import { copingFold, foldBar } from '../core/rebar/coping-fold';
 import { barDepths, barsAcross } from '../core/rebar/bearing-block';
 import { blockFramePoint } from '../core/geometry';
 import { INTEGRATED_BLOCK } from '../core/integrated-block';
@@ -98,7 +99,6 @@ export function buildRebar3D(m: PierModel, common: Material = DEFAULT_MATERIAL,
   const Ms = m.stretches.map((_, k) => stretchMatrix(m, k));
   const L = m.copingL;
   const B = m.copingB;
-  const straight = m.kink === null;
 
   /**
    * A bar through several points as one tube, each bend rounded to its centre-line radius (수정 2026-10-23).
@@ -163,14 +163,27 @@ export function buildRebar3D(m: PierModel, common: Material = DEFAULT_MATERIAL,
     byName.set(name, list);
   };
 
-  // Coping (straight coping only; a bent coping is not drawn in 3D yet).
+  // Coping. A bent coping draws each bar's pieces in their own stretch (coping-fold.ts, 2026-11-10).
-  if (straight && m.columns.length > 1) {
+  if (m.columns.length > 1) {
     for (const b of multicolCopingBars(m, mCoping)) {
-      if (/^C[1-8](-\d+)?$/.test(b.name)) addPath(b.name, 0, b.pts, b.diameterMm, COLOR.coping);
+      for (const p of b.pieces ?? [{ k: 0 as const, pts: b.pts }]) {
-      else for (let i = 1; i < b.pts.length; i++) addBar(b.name, 0, b.pts[i - 1], b.pts[i], b.diameterMm, COLOR.shear);
+        if (/^C[1-8](-\d+)?$/.test(b.name)) addPath(b.name, p.k, p.pts, b.diameterMm, COLOR.coping);
+        else for (let i = 1; i < p.pts.length; i++) addBar(b.name, p.k, p.pts[i - 1], p.pts[i], b.diameterMm, COLOR.shear);
+      }
     }
   }
-  if (straight && m.columns.length <= 1) {
+  if (m.columns.length <= 1) {
+    // T형 on a bent coping: the unfolded bars turn at their mitre point (the mitre shear set and the wedge are multi-column only).
+    const fold = copingFold(m);
+    const tBar = (name: string, k: number, a: [number, number, number], b: [number, number, number], dMm: number, color: number) => {
+      if (!fold) return addBar(name, k, a, b, dMm, color);
+      for (const p of foldBar(fold, [a, b]).pieces) for (let i = 1; i < p.pts.length; i++) addBar(name, p.k, p.pts[i - 1], p.pts[i], dMm, color);
+    };
+    const tPath = (name: string, k: number, pts: [number, number, number][], dMm: number, color: number) => {
+      if (!fold) return addPath(name, k, pts, dMm, color);
+      for (const p of foldBar(fold, pts).pieces) addPath(name, p.k, p.pts, dMm, color);
+    };
+
     const w = widthLayout(B * 1000, m.copingRebar);
     const xs = [w.yE, ...Array.from({ length: w.n + 1 }, (_, i) => w.yE + w.g + w.spacing * i), B * 1000 - w.yE].map((v) => mm(v) - B / 2);
     const cover = 0.1;
@@ -189,8 +202,8 @@ export function buildRebar3D(m: PierModel, common: Material = DEFAULT_MATERIAL,
       xs.forEach((n, j) => {
         const name = `C${k + (j % 2 === 1 ? 0 : 3)}`;
         if (sp) {
-          addPath(name, 0, [[xk, z - hookTop, n], [xk, z, n], [splitX + half, z, n]], NOMINAL_DIAMETER.H29, COLOR.coping);
+          tPath(name, 0, [[xk, z - hookTop, n], [xk, z, n], [splitX + half, z, n]], NOMINAL_DIAMETER.H29, COLOR.coping);
-          addPath(name, 0, [[splitX - half, z, n], [L - xk, z, n], [L - xk, z - hookTop, n]], NOMINAL_DIAMETER.H29, COLOR.coping);
+          tPath(name, 0, [[splitX - half, z, n], [L - xk, z, n], [L - xk, z - hookTop, n]], NOMINAL_DIAMETER.H29, COLOR.coping);
           return;
         }
         const pts: [number, number, number][] = [
@@ -199,7 +212,7 @@ export function buildRebar3D(m: PierModel, common: Material = DEFAULT_MATERIAL,
           [L - xk, z, n],
           [L - xk, z - hookTop, n],
         ];
-        addPath(name, 0, pts, NOMINAL_DIAMETER.H29, COLOR.coping);
+        tPath(name, 0, pts, NOMINAL_DIAMETER.H29, COLOR.coping);
       });
     }
     // Bottom bars C7 / C8 (코핑철근.md §5.2–5.3): they follow the sloped underside, 127 above it, with a vertical leg up
@@ -218,7 +231,7 @@ export function buildRebar3D(m: PierModel, common: Material = DEFAULT_MATERIAL,
       const right = left.map(([x, y, zz]): [number, number, number] => [L - x, y, zz]);
       const name = j % 2 === 1 ? 'C7' : 'C8';
       for (const pts of [left, right]) {
-        addPath(name, 0, pts, NOMINAL_DIAMETER.H29, COLOR.coping);
+        tPath(name, 0, pts, NOMINAL_DIAMETER.H29, COLOR.coping);
       }
     });
     // Shear loops C9 / C10 / C11 and the gaps between columns: a closed U at each position.
@@ -244,12 +257,12 @@ export function buildRebar3D(m: PierModel, common: Material = DEFAULT_MATERIAL,
           // The three 폐합 stack to the right, so no U meets another loop's U or 삿갓 (SHEAR_LOOP_STEP).
           const xu = xm + mm(i * SHEAR_LOOP_STEP);
           const xc = xu + mm(dShear);
-          addBar(name, 0, [xu, bot, a], [xu, bot, b], dShear, COLOR.shear);
+          tBar(name, 0, [xu, bot, a], [xu, bot, b], dShear, COLOR.shear);
-          addBar(name, 0, [xu, bot, a], [xu, top, a], dShear, COLOR.shear);
+          tBar(name, 0, [xu, bot, a], [xu, top, a], dShear, COLOR.shear);
-          addBar(name, 0, [xu, bot, b], [xu, top, b], dShear, COLOR.shear);
+          tBar(name, 0, [xu, bot, b], [xu, top, b], dShear, COLOR.shear);
-          addBar(name, 0, [xc, top, a], [xc, top, b], dShear, COLOR.shear);
+          tBar(name, 0, [xc, top, a], [xc, top, b], dShear, COLOR.shear);
-          addBar(name, 0, [xc, top, a], [xc, capBot, a], dShear, COLOR.shear);
+          tBar(name, 0, [xc, top, a], [xc, capBot, a], dShear, COLOR.shear);
-          addBar(name, 0, [xc, top, b], [xc, capBot, b], dShear, COLOR.shear);
+          tBar(name, 0, [xc, top, b], [xc, capBot, b], dShear, COLOR.shear);
         }
       }
     }
@@ -262,14 +275,14 @@ export function buildRebar3D(m: PierModel, common: Material = DEFAULT_MATERIAL,
     for (const [name, rows] of [['C12', side.c12], ['C13', side.c13]] as const) {
       for (const r of rows) {
         const xw = mm(r.xw);
-        addBar(name, 0, [xw, r.z, -sideFace], [L - xw, r.z, -sideFace], dSide, COLOR.shear);
+        tBar(name, 0, [xw, r.z, -sideFace], [L - xw, r.z, -sideFace], dSide, COLOR.shear);
-        addBar(name, 0, [xw, r.z, sideFace], [L - xw, r.z, sideFace], dSide, COLOR.shear);
+        tBar(name, 0, [xw, r.z, sideFace], [L - xw, r.z, sideFace], dSide, COLOR.shear);
         const zh = r.z + mm(dSide);
         for (const x0 of [xw, L - xw]) {
           const leg = mm(SIDE_HOOK_LEG) * Math.sign(L / 2 - x0);
-          addBar(name, 0, [x0, zh, -sideFace], [x0, zh, sideFace], dSide, COLOR.shear);
+          tBar(name, 0, [x0, zh, -sideFace], [x0, zh, sideFace], dSide, COLOR.shear);
-          addBar(name, 0, [x0, zh, -sideFace], [x0 + leg, zh, -sideFace], dSide, COLOR.shear);
+          tBar(name, 0, [x0, zh, -sideFace], [x0 + leg, zh, -sideFace], dSide, COLOR.shear);
-          addBar(name, 0, [x0, zh, sideFace], [x0 + leg, zh, sideFace], dSide, COLOR.shear);
+          tBar(name, 0, [x0, zh, sideFace], [x0 + leg, zh, sideFace], dSide, COLOR.shear);
         }
       }
     }
@@ -280,18 +293,18 @@ export function buildRebar3D(m: PierModel, common: Material = DEFAULT_MATERIAL,
     const c14Nb = B / 2 - mm(C14_INSET);
     for (const b of c14Bars(L * 1000, topEl, [...side.c13, ...side.c12], (x) => undersideAt(L * 1000, x, m.endBottom, m.levelBottom, m.copingGeom.levelWidth), m.copingRebar.mainLayerGap / 1000)) {
       const xm = mm(b.x);
-      addBar('C14', 0, [xm, b.z, c14Na], [xm, b.z, c14Nb], NOMINAL_DIAMETER.H19, COLOR.coping);
+      tBar('C14', 0, [xm, b.z, c14Na], [xm, b.z, c14Nb], NOMINAL_DIAMETER.H19, COLOR.coping);
       // 연직 발 below the coping underside is left out (코핑철근.md §8).
       if (b.legs) {
-        addBar('C14', 0, [xm, b.z - c14Hook, c14Na], [xm, b.z, c14Na], NOMINAL_DIAMETER.H19, COLOR.coping);
+        tBar('C14', 0, [xm, b.z - c14Hook, c14Na], [xm, b.z, c14Na], NOMINAL_DIAMETER.H19, COLOR.coping);
-        addBar('C14', 0, [xm, b.z, c14Nb], [xm, b.z - c14Hook, c14Nb], NOMINAL_DIAMETER.H19, COLOR.coping);
+        tBar('C14', 0, [xm, b.z, c14Nb], [xm, b.z - c14Hook, c14Nb], NOMINAL_DIAMETER.H19, COLOR.coping);
       }
     }
     // C15 (⊓) and C16 (L형) on the model's own steps (결정 2026-11-10, src/core/rebar/step-bars.ts).
     for (const b of tStepBars(m, mCoping).bars) {
       const n = b.n;
       for (let i = 1; i < b.pts.length; i++) {
-        addBar(b.name, 0, [mm(b.pts[i - 1][0]), b.pts[i - 1][1], n], [mm(b.pts[i][0]), b.pts[i][1], n], NOMINAL_DIAMETER.H19, COLOR.coping);
+        tBar(b.name, 0, [mm(b.pts[i - 1][0]), b.pts[i - 1][1], n], [mm(b.pts[i][0]), b.pts[i][1], n], NOMINAL_DIAMETER.H19, COLOR.coping);
       }
     }
   }

tests/kink-steps.test.ts

@@ -8,6 +8,7 @@ import type { PierInput } from '../src/core/types';
 import { rebarSummary } from '../src/core/rebar/summary';
 import { multicolCopingInfo } from '../src/core/rebar/multicol-coping';
 import { copingFold, inWedge, isTransverse } from '../src/core/rebar/coping-fold';
+import { buildRebar3D } from '../src/view/rebar3d';
 
 // 산외교 P11 (샘플01) with the coping bent 8.767° at IP4 (2026-11-10 검토): back ⑥ g 11.64, ⑦ g 18.49, kink g 15.14.
 const SAMPLE = fileURLToPath(new URL('../project_data/01_엑셀/샘플01_산외교_교각입력데이터.xlsx', import.meta.url));
@@ -186,3 +187,23 @@ describe('꺾인 코핑 철근 접기 (B·C, 2026-11-10)', () => {
     expect(multicolCopingInfo(straight).bars.every((b) => b.pieces === undefined)).toBe(true);
   });
 });
+
+describe('꺾인 코핑 3D 철근 (E, 2026-11-10)', () => {
+  const straightOf = (input: PierInput) => ({ ...input, ips: input.ips.map((q) => (q.name === 'IP4' ? { ...q, angleDeg: 0 } : q)) });
+  const count = (rb: ReturnType<typeof buildRebar3D>, name: string) => rb.byName.get(name)?.length ?? 0;
+
+  it('a bent multi-column coping now draws its coping bars, runs across the kink in two pieces', () => {
+    const bent = buildRebar3D(buildPier(p11()));
+    for (const name of ['C1', 'C7', 'C9', 'C10', 'C12', 'C13', 'C15', 'C16']) expect(count(bent, name), name).toBeGreaterThan(0);
+    const straight = buildRebar3D(buildPier(straightOf(p11())));
+    expect(count(bent, 'C7')).toBeGreaterThan(count(straight, 'C7'));
+  }, 60000);
+
+  it('a bent T형 coping draws its coping bars through the same fold', () => {
+    const t = { ...p11(), type: 'T형' as const, columnCount: 1 };
+    const bent = buildRebar3D(buildPier(t));
+    const straight = buildRebar3D(buildPier(straightOf(t)));
+    expect(count(bent, 'C1')).toBeGreaterThan(0);
+    expect(count(bent, 'C1')).toBeGreaterThan(count(straight, 'C1'));
+  }, 60000);
+});