Revert "Reapply "fix(abut): 날개벽의 연직 헌치 삭제""

This reverts commit 61ef001034.

src/core/abut/wings.ts

@@ -38,6 +38,8 @@ export interface WingSolid {
   topLine: { dM: number; el: number }[];
   /** 하단선: 저판 상면 → 뒷굽 끝 → 단부 하단 (일반형), 또는 저판 상면 평탄 (단축형). */
   bottomLine: { dM: number; el: number }[];
+  /** 헌치 300 × 300 (위 헌치, 흉벽 배면 모서리). 평면 삼각형과 높이 범위. */
+  haunches: Haunch[];
   /**
    * 저판 상면 헌치 (수평, 2026-11-03): between the 저판 상면 and the 날개벽 내측면. The triangle lies in the plane EL–s,
    * with legs HAUNCH_LEG_M along the 저판 상면 and along the 내측면; it runs along the wing from dMFrom (벽체 배면) to dMTo (뒷굽).
@@ -54,6 +56,14 @@ export interface WingBand {
   zBottomEl: number;
 }
 
+export interface Haunch {
+  kind: 'upper' | 'lower';
+  /** 평면 삼각형 꼭짓점 (E, N): 모서리, 날개벽 쪽 점, 벽체·흉벽 쪽 점. */
+  corners: [AbutPoint, AbutPoint, AbutPoint];
+  zBottomEl: number;
+  zTopEl: number;
+}
+
 export const HAUNCH_LEG_M = 0.3;
 
 export function buildWings(model: AbutModel, members: AbutMembers, forms?: { left: WingForm; right: WingForm }): WingSolid[] {
@@ -101,6 +111,28 @@ export function buildWings(model: AbutModel, members: AbutMembers, forms?: { lef
             { dM: WING_LENGTH_M, el: form === 'general' ? bottomEnd : footingTop },
           ];
 
+    // 헌치: 위 헌치는 흉벽 배면(−0.5), 아래 헌치는 벽체 배면(−0.8)의 모서리에 둔다.
+    const pointAt = (d: number) => ({ e: p0.e + w.e * d, n: p0.n + w.n * d });
+    const shift = (q: AbutPoint, v: AbutPoint, f: number) => ({ e: q.e + v.e * f, n: q.n + v.n * f });
+    const bracketTop = topStart - members.shape.bracketHeightM;
+    // The 브라켓 상면 falls along s (the 흉벽 top slopes), so the upper haunch rests on the highest point of its own footprint.
+    const sAt = (q: AbutPoint) => (q.e - model.ip1.e) * model.u.e + (q.n - model.ip1.n) * model.u.n;
+    const backTopAt = (s: number) => members.parapetTopStartEl + ((members.parapetTopEndEl - members.parapetTopStartEl) * s) / model.length - members.shape.bracketHeightM;
+    const haunchAt = (kind: 'upper' | 'lower', t: number): Haunch => {
+      const d = Math.abs(t) / k;
+      const c = pointAt(d);
+      const inwardUnit = { e: model.u.e * a, n: model.u.n * a };
+      const corners: [AbutPoint, AbutPoint, AbutPoint] = [c, shift(c, w, HAUNCH_LEG_M), shift(c, inwardUnit, HAUNCH_LEG_M)];
+      return {
+        kind,
+        corners,
+        zBottomEl: kind === 'upper' ? Math.max(...corners.map((q) => backTopAt(sAt(q)))) : footingTop,
+        zTopEl: kind === 'upper' ? topAt(d) : bracketTop,
+      };
+    };
+    // 연직 헌치 (2026-11-03, 내측면 모서리): upper at the 흉벽 배면, lower at the 벽체 배면.
+    const haunches = [haunchAt('upper', members.shape.parapetBackM), haunchAt('lower', members.shape.wallBackM)];
+
     // 저판 상면 헌치 (수평): from the 벽체 배면 to the 뒷굽, on the 저판 상면 next to the 날개벽 내측면.
     const footingHaunch = {
       dMFrom: Math.abs(members.shape.wallBackM) / k,
@@ -131,6 +163,7 @@ export function buildWings(model: AbutModel, members: AbutMembers, forms?: { lef
       heelDistanceM,
       topLine,
       bottomLine,
+      haunches,
       footingHaunch,
       bands,
     };

src/view/abut-scene.ts

@@ -293,6 +293,15 @@ export function buildAbutGroup(
       const origin = new THREE.Vector3(sEnd + a * WING_THICKNESS_M + dir.ws * f.dMFrom, f.el, dir.wt * f.dMFrom);
       add('haunches', prism(triangle, f.dMTo - f.dMFrom, origin, new THREE.Vector3(a, 0, 0), ey, new THREE.Vector3(dir.ws, 0, dir.wt)), 0xc9a77c);
     }
+    for (const h of wing.haunches) {
+      const shape: [number, number][] = h.corners.map((c) => {
+        const p = toAxis(model, c);
+        return [p.s, p.t];
+      });
+      const zBottom = h.zBottomEl;
+      const height = h.zTopEl - h.zBottomEl;
+      if (height > 0) add('haunches', prism(shape, height, new THREE.Vector3(0, zBottom, 0), ex, ez, ey), 0xc9a77c);
+    }
   }
 
   // 지형: when the ground model's terrain grid covers the abutment footprint, the terrain is drawn (the same frame as the