diff --git a/apps/editor/public/items/ceiling-fan/model.glb b/apps/editor/public/items/ceiling-fan/model.glb
index 093d54dad..b8092f740 100644
Binary files a/apps/editor/public/items/ceiling-fan/model.glb and b/apps/editor/public/items/ceiling-fan/model.glb differ
diff --git a/packages/editor/src/lib/glb-export.test.ts b/packages/editor/src/lib/glb-export.test.ts
index 74b24f70e..cc31fba4f 100644
--- a/packages/editor/src/lib/glb-export.test.ts
+++ b/packages/editor/src/lib/glb-export.test.ts
@@ -1,6 +1,7 @@
 import { afterEach, describe, expect, test } from 'bun:test'
-import { type AnyNode, sceneRegistry } from '@pascal-app/core'
+import { type AnyNode, DoorNode, sceneRegistry } from '@pascal-app/core'
 import * as THREE from 'three'
+import { buildDoorPreviewMesh } from '@pascal-app/viewer'
 import { prepareSceneForExport } from './glb-export'
 
 afterEach(() => {
@@ -135,7 +136,7 @@ describe('prepareSceneForExport', () => {
       kind: 'door',
       label: 'Front door',
       openable: true,
-      clips: ['Front door: open'],
+      clips: ['door_test: open'],
     })
 
     // The swing-leaf marker must not survive into glTF extras.
@@ -245,7 +246,7 @@ describe('prepareSceneForExport', () => {
 
     expect(animations).toHaveLength(1)
     const clip = animations[0]!
-    expect(clip.name).toBe('Door: open')
+    expect(clip.name).toBe('door_swing: open')
     expect(clip.duration).toBe(1)
     // Playback intent carried in extras so consumers can play once and hold.
     expect(clip.userData).toEqual({ loop: false })
@@ -264,4 +265,129 @@ describe('prepareSceneForExport', () => {
     const closed = new THREE.Quaternion().fromArray(Array.from(track.values).slice(0, 4))
     expect(closed.angleTo(new THREE.Quaternion())).toBeCloseTo(0)
   })
+
+  test('bakes a sliding door into a sampled position clip', () => {
+    // Operation doors build their moving parts in a named group posed by
+    // `poseDoorMovingParts`; the exporter samples it into keyframes. The active
+    // panel group slides along x.
+    const root = new THREE.Group()
+    const doorGroup = new THREE.Group()
+    const activePanel = new THREE.Group()
+    activePanel.name = 'door-sliding-active'
+    activePanel.add(meshWithNodeMaterial(nodeMaterial()))
+    doorGroup.add(activePanel)
+    root.add(doorGroup)
+
+    const doorId = 'door_sliding'
+    sceneRegistry.nodes.set(doorId, doorGroup)
+    const nodes: Record<string, AnyNode> = {
+      [doorId]: {
+        object: 'node',
+        id: doorId,
+        type: 'door',
+        name: 'Slider',
+        doorType: 'sliding',
+        slideDirection: 'left',
+        width: 1,
+        height: 2.1,
+        frameThickness: 0.05,
+      } as unknown as AnyNode,
+    }
+
+    const { scene, animations } = prepareSceneForExport(root, nodes)
+
+    expect(animations).toHaveLength(1)
+    const clip = animations[0]!
+    expect(clip.name).toBe('door_sliding: open')
+    expect(clip.duration).toBe(1)
+    expect(clip.userData).toEqual({ loop: false })
+
+    const track = clip.tracks[0]!
+    expect(track).toBeInstanceOf(THREE.VectorKeyframeTrack)
+    expect(track.name.endsWith('.position')).toBe(true)
+    // 16 segments -> 17 keyframes, evenly spaced over the 1s clip.
+    expect(track.times.length).toBe(17)
+    expect(track.times[0]).toBeCloseTo(0)
+    expect(track.times[track.times.length - 1]!).toBeCloseTo(1)
+
+    // Rest pose is closed (first keyframe centred); the panel slides off-centre.
+    expect(track.values[0]!).toBeCloseTo(0)
+    expect(track.values[1]!).toBeCloseTo(0)
+    expect(track.values[2]!).toBeCloseTo(0)
+    const lastX = track.values[track.values.length - 3]!
+    expect(Math.abs(lastX)).toBeGreaterThan(0.1)
+
+    const target = scene.getObjectByProperty('uuid', track.name.replace('.position', ''))
+    expect(target).toBeDefined()
+
+    const exported = scene.getObjectByProperty('name', doorId)
+    expect(exported?.userData.openable).toBe(true)
+    expect(exported?.userData.clips).toEqual(['door_sliding: open'])
+  })
+
+  test('bakes a roll-up curtain into a sampled scale clip', () => {
+    // Roll-up geometry can't vanish in a glTF clip, so the bake scales the
+    // curtain group up into the lintel instead.
+    const root = new THREE.Group()
+    const doorGroup = new THREE.Group()
+    const curtain = new THREE.Group()
+    curtain.name = 'door-rollup-curtain'
+    curtain.add(meshWithNodeMaterial(nodeMaterial()))
+    doorGroup.add(curtain)
+    root.add(doorGroup)
+
+    const doorId = 'door_rollup'
+    sceneRegistry.nodes.set(doorId, doorGroup)
+    const nodes: Record<string, AnyNode> = {
+      [doorId]: {
+        object: 'node',
+        id: doorId,
+        type: 'door',
+        name: 'Roll-up',
+        doorType: 'garage-rollup',
+        width: 2.4,
+        height: 2.2,
+        frameThickness: 0.05,
+      } as unknown as AnyNode,
+    }
+
+    const { animations } = prepareSceneForExport(root, nodes)
+
+    expect(animations).toHaveLength(1)
+    const scaleTrack = animations[0]!.tracks.find((t) => t.name.endsWith('.scale'))
+    expect(scaleTrack).toBeInstanceOf(THREE.VectorKeyframeTrack)
+    // Rest pose is closed (full curtain, scale 1); it shrinks toward the header.
+    expect(Array.from(scaleTrack!.values).slice(0, 3)).toEqual([1, 1, 1])
+    const lastScaleY = scaleTrack!.values[scaleTrack!.values.length - 2]!
+    expect(lastScaleY).toBeLessThan(0.1)
+  })
+
+  // Regression: a folding door saved in an open state (|fold angle| > π/2) used
+  // to bake a 180°-flipped rest pose. The export clones + decomposes the door
+  // matrix, which re-derives a gimbal-flipped euler (x=z=π) for the wide Y
+  // rotation; the pose reset must zero the full euler triple, not just `.y`.
+  test('bakes an identity rest pose for an open folding door', () => {
+    const node = DoorNode.parse({
+      id: 'door_folding',
+      doorType: 'folding',
+      leafCount: 4,
+      operationState: 0.65,
+    })
+    const mesh = buildDoorPreviewMesh(node)
+    const root = new THREE.Group()
+    root.add(mesh)
+    sceneRegistry.nodes.set(node.id, mesh)
+
+    const { scene, animations } = prepareSceneForExport(root, {
+      [node.id]: node as unknown as AnyNode,
+    })
+
+    expect(animations).toHaveLength(1)
+    for (let index = 0; index < 4; index++) {
+      const panel = scene.getObjectByName(`door-fold-${index}`)
+      expect(panel).toBeDefined()
+      // Rest quaternion must be identity — no residual π on any axis.
+      expect(panel!.quaternion.angleTo(new THREE.Quaternion())).toBeLessThan(1e-4)
+    }
+  })
 })
diff --git a/packages/editor/src/lib/glb-export.ts b/packages/editor/src/lib/glb-export.ts
index 7f614993c..31594338a 100644
--- a/packages/editor/src/lib/glb-export.ts
+++ b/packages/editor/src/lib/glb-export.ts
@@ -1,14 +1,21 @@
 import {
   type AnyNode,
+  type DoorNode,
   emitter,
   getLevelDisplayName,
+  isOperationDoorType,
   itemClipRegistry,
   type LevelNode,
   sceneRegistry,
   type WindowNode,
   type ZoneNode,
 } from '@pascal-app/core'
-import { poseWindowMovingParts, SCENE_LAYER, snapLevelsToTruePositions } from '@pascal-app/viewer'
+import {
+  poseDoorMovingParts,
+  poseWindowMovingParts,
+  SCENE_LAYER,
+  snapLevelsToTruePositions,
+} from '@pascal-app/viewer'
 import type { Object3D } from 'three'
 import * as THREE from 'three'
 import { GLTFExporter } from 'three/examples/jsm/exporters/GLTFExporter.js'
@@ -433,12 +440,128 @@ function bakeItemClip(id: string, itemObject: THREE.Object3D): THREE.AnimationCl
   return clip
 }
 
+/**
+ * Bake a door's open motion. Swing doors (hinged/double/french) carry a
+ * `pascalSwingLeaf` marker and bake a single quaternion track per leaf;
+ * operation doors (sliding/pocket/barn/folding/garage-*) build their moving
+ * parts in named groups posed by `poseDoorMovingParts`, sampled here into
+ * keyframes (their motion is non-linear, e.g. the sectional's overhead curve).
+ */
+function bakeDoorClip(
+  id: string,
+  node: AnyNode,
+  doorObject: THREE.Object3D,
+): THREE.AnimationClip | null {
+  if (node.type === 'door' && isOperationDoorType((node as DoorNode).doorType)) {
+    return bakeOperationDoorClip(id, node as DoorNode, doorObject)
+  }
+  return bakeSwingDoorClip(id, node, doorObject)
+}
+
+/** Number of keyframes sampled across an operation door's 0→1 open motion. */
+const OPERATION_DOOR_SAMPLES = 16
+
+/**
+ * Sample an operation door's open motion into keyframe tracks by posing the
+ * export clone with `poseDoorMovingParts` at evenly-spaced fractions. Only the
+ * named moving groups change (their children are rigid), so a track is emitted
+ * per group whose position / rotation / scale actually moves. The clone is left
+ * posed closed so the GLB's rest state is shut.
+ */
+function bakeOperationDoorClip(
+  id: string,
+  node: DoorNode,
+  doorObject: THREE.Object3D,
+): THREE.AnimationClip | null {
+  if (!poseDoorMovingParts(node, doorObject, 0)) return null
+
+  const objects: THREE.Object3D[] = []
+  doorObject.traverse((object) => objects.push(object))
+  const basePoses = objects.map((object) => ({
+    position: object.position.clone(),
+    quaternion: object.quaternion.clone(),
+    scale: object.scale.clone(),
+  }))
+
+  const times: number[] = []
+  const positionSamples = objects.map(() => [] as number[])
+  const quaternionSamples = objects.map(() => [] as number[])
+  const scaleSamples = objects.map(() => [] as number[])
+
+  for (let step = 0; step <= OPERATION_DOOR_SAMPLES; step++) {
+    const t = step / OPERATION_DOOR_SAMPLES
+    times.push(t)
+    poseDoorMovingParts(node, doorObject, t)
+    for (let i = 0; i < objects.length; i++) {
+      const object = objects[i]!
+      positionSamples[i]!.push(...object.position.toArray())
+      quaternionSamples[i]!.push(...object.quaternion.toArray())
+      scaleSamples[i]!.push(...object.scale.toArray())
+    }
+  }
+
+  const tracks: THREE.KeyframeTrack[] = []
+  for (let i = 0; i < objects.length; i++) {
+    const object = objects[i]!
+    const base = basePoses[i]!
+    if (samplesMovePosition(positionSamples[i]!, base.position)) {
+      tracks.push(
+        new THREE.VectorKeyframeTrack(`${object.uuid}.position`, times, positionSamples[i]!),
+      )
+    }
+    if (samplesMoveQuaternion(quaternionSamples[i]!, base.quaternion)) {
+      tracks.push(
+        new THREE.QuaternionKeyframeTrack(
+          `${object.uuid}.quaternion`,
+          times,
+          quaternionSamples[i]!,
+        ),
+      )
+    }
+    if (samplesMoveScale(scaleSamples[i]!, base.scale)) {
+      tracks.push(new THREE.VectorKeyframeTrack(`${object.uuid}.scale`, times, scaleSamples[i]!))
+    }
+  }
+
+  poseDoorMovingParts(node, doorObject, 0)
+
+  if (tracks.length === 0) return null
+  return openClip(id, tracks)
+}
+
+function samplesMovePosition(flat: number[], base: THREE.Vector3): boolean {
+  const point = new THREE.Vector3()
+  for (let i = 0; i < flat.length; i += 3) {
+    point.set(flat[i]!, flat[i + 1]!, flat[i + 2]!)
+    if (point.distanceToSquared(base) > POSE_EPSILON) return true
+  }
+  return false
+}
+
+function samplesMoveQuaternion(flat: number[], base: THREE.Quaternion): boolean {
+  const quaternion = new THREE.Quaternion()
+  for (let i = 0; i < flat.length; i += 4) {
+    quaternion.set(flat[i]!, flat[i + 1]!, flat[i + 2]!, flat[i + 3]!)
+    if (base.angleTo(quaternion) > POSE_EPSILON) return true
+  }
+  return false
+}
+
+function samplesMoveScale(flat: number[], base: THREE.Vector3): boolean {
+  const point = new THREE.Vector3()
+  for (let i = 0; i < flat.length; i += 3) {
+    point.set(flat[i]!, flat[i + 1]!, flat[i + 2]!)
+    if (point.distanceToSquared(base) > POSE_EPSILON) return true
+  }
+  return false
+}
+
 /**
  * Bake a swing door's open motion. Each marked leaf is rotated from closed
  * (rest pose) to its fully-open angle and emitted as a 1-second quaternion
  * track; the leaf is left at the closed pose so the GLB's rest state is shut.
  */
-function bakeDoorClip(
+function bakeSwingDoorClip(
   id: string,
   node: AnyNode,
   doorObject: THREE.Object3D,
@@ -465,21 +588,24 @@ function bakeDoorClip(
   })
 
   if (tracks.length === 0) return null
-  return openClip(id, node, tracks)
+  return openClip(id, tracks)
 }
 
 /**
- * Wrap an open motion in a named 1-second clip. The name uses the node's label
- * when set (e.g. "Door 1: open") so a glTF player lists readable clips, falling
- * back to the id. glTF has no core loop flag — the player decides — so we stamp
- * `extras.loop = false` (via the clip's userData, which `GLTFExporter`
- * serialises onto the animation): Pascal's `/viewer` and any extras-aware
- * consumer play it once and hold the open pose; a dumb glTF player still loops.
- * Consumers map a clip back to its node by walking up from a channel's target to
- * the nearest ancestor carrying `extras.pascalId`, so the name stays cosmetic.
+ * Wrap an open motion in a named 1-second clip. The name is keyed by the node id
+ * (`<id>: open`), NOT the node's display name: clip names must be unique because
+ * the baked viewer drives playback by clip name (`useAnimations` maps name →
+ * action), so two same-named openables (e.g. several "Window 1"s) would collapse
+ * to a single action and a trigger on one would animate another. The
+ * human-readable name lives in `extras.label` instead. glTF has no core loop
+ * flag — the player decides — so we stamp `extras.loop = false` (via the clip's
+ * userData, which `GLTFExporter` serialises onto the animation): Pascal's
+ * `/viewer` and any extras-aware consumer play it once and hold the open pose; a
+ * dumb glTF player still loops. Consumers map a clip back to its node by walking
+ * up from a channel's target to the nearest ancestor carrying `extras.pascalId`.
  */
-function openClip(id: string, node: AnyNode, tracks: THREE.KeyframeTrack[]): THREE.AnimationClip {
-  const clip = new THREE.AnimationClip(`${node.name ?? id}: open`, 1, tracks)
+function openClip(id: string, tracks: THREE.KeyframeTrack[]): THREE.AnimationClip {
+  const clip = new THREE.AnimationClip(`${id}: open`, 1, tracks)
   clip.userData = { loop: false }
   return clip
 }
@@ -539,7 +665,7 @@ function bakeWindowClip(
   poseWindowMovingParts(node, windowObject, 0)
 
   if (tracks.length === 0) return null
-  return openClip(id, node, tracks)
+  return openClip(id, tracks)
 }
 
 // --- Identity stamping ---------------------------------------------------
diff --git a/packages/viewer/src/components/viewer/glb-walkthrough-controller.tsx b/packages/viewer/src/components/viewer/glb-walkthrough-controller.tsx
index f235f773f..50c835429 100644
--- a/packages/viewer/src/components/viewer/glb-walkthrough-controller.tsx
+++ b/packages/viewer/src/components/viewer/glb-walkthrough-controller.tsx
@@ -15,6 +15,7 @@ import {
   Mesh,
   MeshBasicMaterial,
   type Object3D,
+  type PerspectiveCamera,
   Quaternion,
   Vector3,
 } from 'three'
@@ -24,6 +25,7 @@ import { useGLTFKTX2 } from '../../hooks/use-gltf-ktx2'
 import { SCENE_LAYER } from '../../lib/layers'
 import useViewer from '../../store/use-viewer'
 import BVHEcctrl, { type BVHEcctrlApi, type MovementInput } from './bvh-ecctrl'
+import { WALKTHROUGH_FOV } from './walkthrough-controls'
 
 // Eye/capsule geometry mirrors the editor's first-person controller so the
 // baked walkthrough feels identical. The capsule centre sits below the eye; the
@@ -264,6 +266,22 @@ export function GlbWalkthroughController({ url }: { url: string }) {
     }
   }, [])
 
+  // Widen FOV while walking; the baked walkthrough rides the default 50° orbit
+  // camera, which feels cramped on foot. Keyed on `camera` so it re-applies if
+  // the instance swaps (e.g. the ortho→perspective switch above), restoring the
+  // prior FOV on exit.
+  useEffect(() => {
+    const cam = camera as PerspectiveCamera
+    if (!cam.isPerspectiveCamera) return
+    const prevFov = cam.fov
+    cam.fov = WALKTHROUGH_FOV
+    cam.updateProjectionMatrix()
+    return () => {
+      cam.fov = prevFov
+      cam.updateProjectionMatrix()
+    }
+  }, [camera])
+
   useEffect(() => {
     worldRef.current = world
     if (world) {
diff --git a/packages/viewer/src/components/viewer/walkthrough-controls.tsx b/packages/viewer/src/components/viewer/walkthrough-controls.tsx
index b3d55f288..65c6b69f1 100644
--- a/packages/viewer/src/components/viewer/walkthrough-controls.tsx
+++ b/packages/viewer/src/components/viewer/walkthrough-controls.tsx
@@ -3,12 +3,18 @@
 import { PointerLockControls } from '@react-three/drei'
 import { useFrame, useThree } from '@react-three/fiber'
 import { useCallback, useEffect, useRef } from 'react'
-import { Vector3 } from 'three'
+import { type PerspectiveCamera, Vector3 } from 'three'
 import useViewer from '../../store/use-viewer'
 
 const MOVE_SPEED = 5
 const EYE_HEIGHT = 1.6
 
+// First-person FOV. The orbit camera is 50° (set on the Canvas), which feels
+// cramped on foot; ~60° vertical (~90° horizontal at 16:9) restores peripheral
+// awareness without wide-angle distortion. Applied only while walking — both
+// walkthrough controllers read this and restore the orbit FOV on exit.
+export const WALKTHROUGH_FOV = 60
+
 const _direction = new Vector3()
 const _forward = new Vector3()
 const _right = new Vector3()
@@ -26,6 +32,20 @@ export const WalkthroughControls = () => {
     }
   }, [walkthroughMode, camera])
 
+  // Widen FOV while walking; restore the orbit FOV on exit.
+  useEffect(() => {
+    if (!walkthroughMode) return
+    const cam = camera as PerspectiveCamera
+    if (!cam.isPerspectiveCamera) return
+    const prevFov = cam.fov
+    cam.fov = WALKTHROUGH_FOV
+    cam.updateProjectionMatrix()
+    return () => {
+      cam.fov = prevFov
+      cam.updateProjectionMatrix()
+    }
+  }, [walkthroughMode, camera])
+
   // Keyboard handlers
   useEffect(() => {
     if (!walkthroughMode) return
diff --git a/packages/viewer/src/index.ts b/packages/viewer/src/index.ts
index 498ad03ea..761e4ce54 100644
--- a/packages/viewer/src/index.ts
+++ b/packages/viewer/src/index.ts
@@ -111,7 +111,7 @@ export {
   createColumnTorusGeometry,
 } from './systems/column/column-geometry'
 export { DoorAnimationSystem } from './systems/door/door-animation-system'
-export { buildDoorPreviewMesh, DoorSystem } from './systems/door/door-system'
+export { buildDoorPreviewMesh, DoorSystem, poseDoorMovingParts } from './systems/door/door-system'
 export { ElevatorInteractionSystem } from './systems/elevator/elevator-interaction-system'
 // Fence system follows the wall re-export pattern — composed into the
 // registry-driven fence definition's `def.system`. Removed in Phase 6
diff --git a/packages/viewer/src/systems/door/door-animation.test.ts b/packages/viewer/src/systems/door/door-animation.test.ts
new file mode 100644
index 000000000..4b1b9735a
--- /dev/null
+++ b/packages/viewer/src/systems/door/door-animation.test.ts
@@ -0,0 +1,59 @@
+// @ts-expect-error — bun:test is provided by the Bun runtime; viewer does not
+// depend on @types/bun so the import type is unresolved at compile time.
+import { describe, expect, test } from 'bun:test'
+import { DoorNode } from '@pascal-app/core'
+import * as THREE from 'three'
+import { buildDoorPreviewMesh, poseDoorMovingParts } from '../../index'
+
+// The named moving group each operation-door builder emits at the closed pose.
+const MOVING_GROUP: Record<string, string> = {
+  sliding: 'door-sliding-active',
+  pocket: 'door-pocket-leaf',
+  barn: 'door-barn-leaf',
+  'garage-tiltup': 'door-tiltup-leaf',
+  folding: 'door-fold-0',
+  'garage-sectional': 'door-sectional-0',
+  'garage-rollup': 'door-rollup-curtain',
+}
+
+function worldPosition(object: THREE.Object3D): THREE.Vector3 {
+  object.updateMatrixWorld(true)
+  return object.getWorldPosition(new THREE.Vector3())
+}
+
+describe('operation door open kinematics', () => {
+  // Each operation door builds its moving parts in a named group at the closed
+  // pose; `poseDoorMovingParts` then drives the open motion (the single source
+  // of truth shared by the live system and the GLB exporter). This guards the
+  // build-once + pose-at-t contract: the group exists, rests closed, and moves.
+  for (const doorType of Object.keys(MOVING_GROUP)) {
+    test(`${doorType} builds a moving group that opens`, () => {
+      const node = DoorNode.parse({ id: `door_${doorType}`, doorType, operationState: 0 })
+      const mesh = buildDoorPreviewMesh(node)
+
+      const group = mesh.getObjectByName(MOVING_GROUP[doorType]!)
+      expect(group).toBeDefined()
+
+      // Closed snapshot.
+      poseDoorMovingParts(node, mesh, 0)
+      const closedPos = worldPosition(group!)
+      const closedScaleY = group!.scale.y
+      const closedRotX = group!.rotation.x
+      const closedRotY = group!.rotation.y
+
+      // Open snapshot — at least one of translation / rotation / scale changes.
+      poseDoorMovingParts(node, mesh, 1)
+      const openPos = worldPosition(group!)
+      const moved =
+        closedPos.distanceTo(openPos) > 0.05 ||
+        Math.abs(closedScaleY - group!.scale.y) > 0.1 ||
+        Math.abs(closedRotX - group!.rotation.x) > 0.05 ||
+        Math.abs(closedRotY - group!.rotation.y) > 0.05
+      expect(moved).toBe(true)
+
+      // Posing back to closed is the identity of the rest pose.
+      poseDoorMovingParts(node, mesh, 0)
+      expect(worldPosition(group!).distanceTo(closedPos)).toBeLessThan(1e-6)
+    })
+  }
+})
diff --git a/packages/viewer/src/systems/door/door-system.tsx b/packages/viewer/src/systems/door/door-system.tsx
index ea3413c56..ce84353d2 100644
--- a/packages/viewer/src/systems/door/door-system.tsx
+++ b/packages/viewer/src/systems/door/door-system.tsx
@@ -273,26 +273,6 @@ function addRotatedBox(
   parent.add(m)
 }
 
-function addBoxWithRotation(
-  parent: THREE.Object3D,
-  material: THREE.Material,
-  w: number,
-  h: number,
-  d: number,
-  x: number,
-  y: number,
-  z: number,
-  rotation: [number, number, number],
-) {
-  const geometry = new THREE.BoxGeometry(w, h, d)
-  applyWorldScaleBoxUVs(geometry, w, h, d)
-  const m = new THREE.Mesh(geometry, material)
-  m.position.set(x, y, z)
-  m.rotation.set(rotation[0], rotation[1], rotation[2])
-  tagDoorSlot(m)
-  parent.add(m)
-}
-
 function addShape(
   parent: THREE.Object3D,
   material: THREE.Material,
@@ -1335,6 +1315,156 @@ function addDoorLeaf(
   }
 }
 
+// Names of the re-poseable moving groups each operation-door builder emits. The
+// builder fills them with geometry at the CLOSED pose; `poseDoorMovingParts`
+// then transforms the group to a given open fraction. This is the same
+// build-once + pose-at-t split windows use (`poseWindowMovingParts`), and it is
+// the single source of truth for door kinematics: the live system poses the
+// registered mesh, and the GLB exporter poses an export clone to sample the
+// open/close keyframes for a baked animation clip.
+const SLIDING_ACTIVE_PANEL_NAME = 'door-sliding-active'
+const POCKET_LEAF_NAME = 'door-pocket-leaf'
+const BARN_LEAF_NAME = 'door-barn-leaf'
+const TILTUP_LEAF_NAME = 'door-tiltup-leaf'
+// Folding panels form a hinged chain; each `<name><index>` group is parented to
+// the previous one so a single per-joint rotation reproduces the accordion.
+const FOLDING_PANEL_NAME = 'door-fold-'
+// Sectional panels each ride the overhead curve independently (non-rigid as a
+// set), so each `<name><index>` group is posed on its own.
+const SECTIONAL_PANEL_NAME = 'door-sectional-'
+const ROLLUP_CURTAIN_NAME = 'door-rollup-curtain'
+
+/**
+ * Pose an operation door's moving parts (sliding/pocket/barn leaf, tilt-up and
+ * sectional panels, folding chain, roll-up curtain) at `value` (0 = closed,
+ * 1 = open) by transforming the named groups its builder emitted at the closed
+ * pose. Returns true when the door type has a pose path and its groups exist.
+ *
+ * Mirrors `poseWindowMovingParts`: the live door system calls it after a
+ * (re)build so `operationState` is reflected, and the GLB exporter calls it on a
+ * clone to sample keyframes. Swing doors are not handled here — their leaf group
+ * carries a `pascalSwingLeaf` marker the exporter reads directly.
+ *
+ * Roll-up is the one type whose live geometry changes (slats vanish onto a
+ * drum), which a glTF clip can't express; the baked approximation scales the
+ * curtain up into the lintel. The live roll-up animation keeps its full-detail
+ * rebuild and is intentionally NOT routed through this scale.
+ */
+export function poseDoorMovingParts(
+  node: DoorNode,
+  mesh: THREE.Object3D | undefined,
+  value: number,
+): boolean {
+  if (!mesh) return false
+  const t = clampDoorOperationState(value)
+  const frameThickness = node.frameThickness
+  const insideWidth = node.width - 2 * frameThickness
+  const leafHeight = node.height - frameThickness
+  const leafCenterY = -frameThickness / 2
+
+  switch (node.doorType) {
+    case 'sliding': {
+      const group = mesh.getObjectByName(SLIDING_ACTIVE_PANEL_NAME)
+      if (!group) return false
+      const activeSign = node.slideDirection === 'left' ? 1 : -1
+      group.position.x = -activeSign * insideWidth * 0.44 * t
+      return true
+    }
+    case 'pocket': {
+      const group = mesh.getObjectByName(POCKET_LEAF_NAME)
+      if (!group) return false
+      const slideSign = node.slideDirection === 'right' ? 1 : -1
+      group.position.x = slideSign * insideWidth * t
+      return true
+    }
+    case 'barn': {
+      const group = mesh.getObjectByName(BARN_LEAF_NAME)
+      if (!group) return false
+      const slideSign = node.slideDirection === 'right' ? 1 : -1
+      group.position.x = slideSign * insideWidth * t
+      return true
+    }
+    case 'garage-tiltup': {
+      const group = mesh.getObjectByName(TILTUP_LEAF_NAME)
+      if (!group) return false
+      // Rigid hinge: the closed leaf hangs from the lintel; opening rotates it
+      // about the top edge. `position` keeps the top edge tracking the hinge as
+      // the group rotates about its own origin (see the closed build below).
+      const angle = (Math.PI / 2) * t
+      const hingeY = leafCenterY + leafHeight / 2
+      group.rotation.set(-angle, 0, 0)
+      group.position.set(0, hingeY * (1 - Math.cos(angle)), Math.sin(angle) * (hingeY - leafHeight))
+      return true
+    }
+    case 'folding': {
+      const panelCount = node.leafCount === 2 ? 2 : 4
+      const foldAngle = Math.PI * 0.44 * t
+      // Each panel group is parented to the previous, so its rotation is the
+      // joint angle (the change in absolute segment direction), not the absolute
+      // angle: alternating panels target ∓foldAngle, so joints fold by ±2·angle.
+      // The leading sign folds the leaves toward −z (matching the original rig).
+      let posed = false
+      let prevDirection = 0
+      for (let index = 0; index < panelCount; index++) {
+        const group = mesh.getObjectByName(`${FOLDING_PANEL_NAME}${index}`)
+        const direction = index % 2 === 0 ? -1 : 1
+        if (group) {
+          posed = true
+          // Set the full triple (not just `.y`): when the export clones and
+          // decomposes the door matrix, a |Y| > π/2 rotation re-derives into a
+          // gimbal-flipped euler (x=z=π). Assigning only `.y` would leave that
+          // π residue on x/z and bake a flipped rest pose.
+          group.rotation.set(0, (prevDirection - direction) * foldAngle, 0)
+        }
+        prevDirection = direction
+      }
+      return posed
+    }
+    case 'garage-sectional': {
+      const panelCount = Math.max(3, Math.min(12, Math.round(node.garagePanelCount)))
+      const panelHeight = leafHeight / panelCount
+      const curveRadius = panelHeight * 0.58
+      const curveLength = (Math.PI / 2) * curveRadius
+      const overheadY = leafCenterY + leafHeight / 2 - panelHeight / 2
+      const openAmount = getDoorRenderOpenAmount('garage-sectional', t)
+      const travel =
+        openAmount * ((panelCount - 1) * panelHeight + curveLength + panelHeight * 0.65)
+      let posed = false
+      for (let index = 0; index < panelCount; index++) {
+        const group = mesh.getObjectByName(`${SECTIONAL_PANEL_NAME}${index}`)
+        if (!group) continue
+        posed = true
+        const orderFromTop = panelCount - 1 - index
+        const pathPosition = travel - orderFromTop * panelHeight
+        let y = overheadY + pathPosition
+        let z = 0
+        let rotationX = 0
+        if (pathPosition > 0 && pathPosition <= curveLength) {
+          const theta = pathPosition / curveRadius
+          rotationX = -theta
+          y = overheadY + curveRadius * Math.sin(theta)
+          z = -curveRadius * (1 - Math.cos(theta))
+        } else if (pathPosition > curveLength) {
+          rotationX = -Math.PI / 2
+          y = overheadY + curveRadius
+          z = -(curveRadius + pathPosition - curveLength)
+        }
+        group.position.set(0, y, z)
+        group.rotation.set(rotationX, 0, 0)
+      }
+      return posed
+    }
+    case 'garage-rollup': {
+      const group = mesh.getObjectByName(ROLLUP_CURTAIN_NAME)
+      if (!group) return false
+      group.scale.y = Math.max(0.02, 1 - t)
+      return true
+    }
+    default:
+      return false
+  }
+}
+
 function addFoldingDoor(
   mesh: THREE.Mesh,
   {
@@ -1344,7 +1474,6 @@ function addFoldingDoor(
     leafDepth,
     frameThickness,
     frameDepth,
-    operationState,
     leafCount,
     doorHeight,
     handleHeight,
@@ -1357,7 +1486,6 @@ function addFoldingDoor(
     leafDepth: number
     frameThickness: number
     frameDepth: number
-    operationState: number
     leafCount: DoorNode['leafCount']
     doorHeight: number
     handleHeight: number
@@ -1366,9 +1494,7 @@ function addFoldingDoor(
   },
 ) {
   const panelCount = leafCount === 2 ? 2 : 4
-  const foldAmount = clampDoorOperationState(operationState)
   const panelLength = insideWidth / panelCount
-  const foldAngle = Math.PI * 0.44 * foldAmount
 
   currentDoorSlot = 'hardware'
   addBox(
@@ -1382,31 +1508,20 @@ function addFoldingDoor(
     0,
   )
 
-  const vertices: Array<{ x: number; z: number }> = [{ x: -insideWidth / 2, z: 0 }]
+  // Build the panels as a hinged chain at the CLOSED pose: each panel group is
+  // parented to the previous one at that panel's end (`panelLength` along local
+  // x), starting from the left jamb. At rest every joint is straight, so the
+  // panels lie flat across the opening; `poseDoorMovingParts` folds the joints.
+  let parent: THREE.Object3D = mesh
   for (let index = 0; index < panelCount; index++) {
-    const previous = vertices[index]!
-    const direction = index % 2 === 0 ? -1 : 1
-    const angle = direction * foldAngle
-    vertices.push({
-      x: previous.x + panelLength * Math.cos(angle),
-      z: previous.z + panelLength * Math.sin(angle),
-    })
-  }
-
-  currentDoorSlot = undefined
-  for (let index = 0; index < panelCount; index++) {
-    const start = vertices[index]!
-    const end = vertices[index + 1]!
-    const dx = end.x - start.x
-    const dz = end.z - start.z
-    const centerX = (start.x + end.x) / 2
-    const centerZ = (start.z + end.z) / 2
-    const rotationY = Math.atan2(-dz, dx)
-    const localX = {
-      x: Math.cos(rotationY),
-      z: -Math.sin(rotationY),
-    }
+    const group = new THREE.Group()
+    group.name = `${FOLDING_PANEL_NAME}${index}`
+    group.position.set(index === 0 ? -insideWidth / 2 : panelLength, 0, 0)
+    parent.add(group)
 
+    // Panel content runs from local x=0 to x=panelLength, so it is centred at
+    // panelLength/2 within the group (the segment helper centres on leafCenterX).
+    currentDoorSlot = undefined
     const addFoldingLeafBox = (
       material: THREE.Material,
       w: number,
@@ -1415,19 +1530,7 @@ function addFoldingDoor(
       x: number,
       y: number,
       z: number,
-    ) => {
-      addRotatedBox(
-        mesh,
-        material,
-        w,
-        h,
-        d,
-        centerX + localX.x * x + Math.sin(rotationY) * z,
-        y,
-        centerZ + localX.z * x + Math.cos(rotationY) * z,
-        rotationY,
-      )
-    }
+    ) => addBox(group, material, w, h, d, panelLength / 2 + x, y, z)
 
     addLeafSegmentContent({
       addLeafBox: addFoldingLeafBox,
@@ -1441,43 +1544,37 @@ function addFoldingDoor(
       keepFrameWhenEmpty: true,
     })
 
+    // Reveal posts at the panel's hinge edges (local x=0 and x=panelLength).
     currentDoorSlot = undefined
-    for (const point of [start, end]) {
-      addBox(
-        mesh,
-        revealMaterial,
-        0.018,
-        leafHeight * 0.92,
-        leafDepth + 0.016,
-        point.x,
-        leafCenterY,
-        point.z,
-      )
+    for (const px of [0, panelLength]) {
+      addBox(group, revealMaterial, 0.018, leafHeight * 0.92, leafDepth + 0.016, px, leafCenterY, 0)
     }
+
+    parent = group
   }
 
-  const handlePoint = vertices[vertices.length - 1]!
+  // Handle on the free end of the last panel (its local x=panelLength edge).
   const handleY = handleHeight - doorHeight / 2
   currentDoorSlot = 'hardware'
   addBox(
-    mesh,
+    parent,
     hardwareMaterial,
     0.035,
     0.16,
     leafDepth + 0.035,
-    handlePoint.x - 0.035,
+    panelLength - 0.035,
     handleY,
-    handlePoint.z + 0.045,
+    0.045,
   )
   addBox(
-    mesh,
+    parent,
     hardwareMaterial,
     0.035,
     0.16,
     leafDepth + 0.035,
-    handlePoint.x - 0.035,
+    panelLength - 0.035,
     handleY,
-    handlePoint.z - 0.045,
+    -0.045,
   )
 }
 
@@ -1490,7 +1587,6 @@ function addPocketDoor(
     leafDepth,
     frameThickness,
     frameDepth,
-    operationState,
     slideDirection,
     doorHeight,
     handleHeight,
@@ -1503,7 +1599,6 @@ function addPocketDoor(
     leafDepth: number
     frameThickness: number
     frameDepth: number
-    operationState: number
     slideDirection: DoorNode['slideDirection']
     doorHeight: number
     handleHeight: number
@@ -1511,14 +1606,14 @@ function addPocketDoor(
     contentPadding: DoorNode['contentPadding']
   },
 ) {
-  const openAmount = clampDoorOperationState(operationState)
   const slideSign = slideDirection === 'right' ? 1 : -1
   const leafWidth = insideWidth
-  const leafCenterX = slideSign * insideWidth * openAmount
   const topY = leafCenterY + leafHeight / 2
   const pocketCenterX = slideSign * insideWidth
   const handleY = handleHeight - doorHeight / 2
-  const handleX = leafCenterX - slideSign * (leafWidth / 2 - 0.055)
+  // Leaf built closed (centred in the opening); `poseDoorMovingParts` slides the
+  // group into the pocket. Handle rides inside the group at its closed offset.
+  const handleX = -slideSign * (leafWidth / 2 - 0.055)
 
   currentDoorSlot = 'hardware'
   addBox(
@@ -1553,6 +1648,10 @@ function addPocketDoor(
     0,
   )
 
+  const leafGroup = new THREE.Group()
+  leafGroup.name = POCKET_LEAF_NAME
+  mesh.add(leafGroup)
+
   const addPocketLeafBox = (
     material: THREE.Material,
     w: number,
@@ -1561,13 +1660,13 @@ function addPocketDoor(
     x: number,
     y: number,
     z: number,
-  ) => addBox(mesh, material, w, h, d, x, y, z)
+  ) => addBox(leafGroup, material, w, h, d, x, y, z)
 
   addLeafSegmentContent({
     addLeafBox: addPocketLeafBox,
     leafWidth,
     leafHeight,
-    leafCenterX,
+    leafCenterX: 0,
     leafCenterY,
     leafDepth,
     segments,
@@ -1575,7 +1674,7 @@ function addPocketDoor(
   })
   currentDoorSlot = 'hardware'
   addBox(
-    mesh,
+    leafGroup,
     hardwareMaterial,
     0.03,
     0.18,
@@ -1585,7 +1684,7 @@ function addPocketDoor(
     leafDepth / 2 + 0.02,
   )
   addBox(
-    mesh,
+    leafGroup,
     hardwareMaterial,
     0.03,
     0.18,
@@ -1605,7 +1704,6 @@ function addBarnDoor(
     leafDepth,
     frameThickness,
     frameDepth,
-    operationState,
     slideDirection,
     doorHeight,
     handleHeight,
@@ -1618,7 +1716,6 @@ function addBarnDoor(
     leafDepth: number
     frameThickness: number
     frameDepth: number
-    operationState: number
     slideDirection: DoorNode['slideDirection']
     doorHeight: number
     handleHeight: number
@@ -1626,16 +1723,17 @@ function addBarnDoor(
     contentPadding: DoorNode['contentPadding']
   },
 ) {
-  const openAmount = clampDoorOperationState(operationState)
   const slideSign = slideDirection === 'right' ? 1 : -1
   const leafWidth = insideWidth * 1.06
-  const leafCenterX = slideSign * insideWidth * openAmount
   const faceZ = frameDepth / 2 + leafDepth / 2 + 0.028
   const trackY = leafCenterY + leafHeight / 2 + Math.max(frameThickness * 0.55, 0.045)
   const railLength = insideWidth * 2.25
   const railCenterX = slideSign * (insideWidth * 0.56)
   const handleY = handleHeight - doorHeight / 2
-  const handleX = leafCenterX - slideSign * (leafWidth / 2 - 0.075)
+  // Leaf + wheels + handle ride the BARN_LEAF group, built closed (leaf centred
+  // in the opening); `poseDoorMovingParts` slides the group along the rail. The
+  // rail and end stops stay static on the mesh.
+  const handleX = -slideSign * (leafWidth / 2 - 0.075)
   const wheelY = trackY - 0.075
 
   currentDoorSlot = 'hardware'
@@ -1643,6 +1741,10 @@ function addBarnDoor(
   addBox(mesh, hardwareMaterial, 0.05, 0.13, 0.035, -insideWidth / 2, trackY - 0.02, faceZ + 0.01)
   addBox(mesh, hardwareMaterial, 0.05, 0.13, 0.035, insideWidth / 2, trackY - 0.02, faceZ + 0.01)
 
+  const leafGroup = new THREE.Group()
+  leafGroup.name = BARN_LEAF_NAME
+  mesh.add(leafGroup)
+
   const addBarnLeafBox = (
     material: THREE.Material,
     w: number,
@@ -1651,13 +1753,13 @@ function addBarnDoor(
     x: number,
     y: number,
     z: number,
-  ) => addBox(mesh, material, w, h, d, x, y, faceZ + z)
+  ) => addBox(leafGroup, material, w, h, d, x, y, faceZ + z)
 
   addLeafSegmentContent({
     addLeafBox: addBarnLeafBox,
     leafWidth,
     leafHeight,
-    leafCenterX,
+    leafCenterX: 0,
     leafCenterY,
     leafDepth,
     segments,
@@ -1667,23 +1769,23 @@ function addBarnDoor(
 
   currentDoorSlot = undefined
   addRotatedBox(
-    mesh,
+    leafGroup,
     revealMaterial,
     0.018,
     leafHeight * 0.86,
     0.012,
-    leafCenterX,
+    0,
     leafCenterY,
     faceZ + leafDepth / 2 + 0.014,
     -0.52,
   )
   addRotatedBox(
-    mesh,
+    leafGroup,
     revealMaterial,
     0.018,
     leafHeight * 0.86,
     0.012,
-    leafCenterX,
+    0,
     leafCenterY,
     faceZ + leafDepth / 2 + 0.014,
     0.52,
@@ -1691,22 +1793,13 @@ function addBarnDoor(
 
   currentDoorSlot = 'hardware'
   for (const offset of [-leafWidth * 0.28, leafWidth * 0.28]) {
-    addBox(mesh, hardwareMaterial, 0.085, 0.085, 0.035, leafCenterX + offset, wheelY, faceZ + 0.022)
-    addBox(
-      mesh,
-      hardwareMaterial,
-      0.026,
-      0.16,
-      0.026,
-      leafCenterX + offset,
-      wheelY - 0.075,
-      faceZ + 0.022,
-    )
+    addBox(leafGroup, hardwareMaterial, 0.085, 0.085, 0.035, offset, wheelY, faceZ + 0.022)
+    addBox(leafGroup, hardwareMaterial, 0.026, 0.16, 0.026, offset, wheelY - 0.075, faceZ + 0.022)
   }
 
   currentDoorSlot = 'hardware'
   addBox(
-    mesh,
+    leafGroup,
     hardwareMaterial,
     0.032,
     0.22,
@@ -1716,7 +1809,7 @@ function addBarnDoor(
     faceZ + leafDepth / 2 + 0.02,
   )
   addBox(
-    mesh,
+    leafGroup,
     hardwareMaterial,
     0.032,
     0.22,
@@ -1736,7 +1829,6 @@ function addSlidingDoor(
     leafDepth,
     frameThickness,
     frameDepth,
-    operationState,
     slideDirection,
     doorHeight,
     handleHeight,
@@ -1749,7 +1841,6 @@ function addSlidingDoor(
     leafDepth: number
     frameThickness: number
     frameDepth: number
-    operationState: number
     slideDirection: DoorNode['slideDirection']
     doorHeight: number
     handleHeight: number
@@ -1757,7 +1848,6 @@ function addSlidingDoor(
     contentPadding: DoorNode['contentPadding']
   },
 ) {
-  const openAmount = clampDoorOperationState(operationState)
   const activeOnRight = slideDirection === 'left'
   const fixedSign = activeOnRight ? -1 : 1
   const activeSign = activeOnRight ? 1 : -1
@@ -1765,12 +1855,14 @@ function addSlidingDoor(
   const panelHeight = leafHeight
   const closedActiveX = activeSign * insideWidth * 0.23
   const fixedX = fixedSign * insideWidth * 0.23
-  const activeX = closedActiveX - activeSign * insideWidth * 0.44 * openAmount
   const frontZ = leafDepth / 2 + 0.016
   const backZ = -leafDepth / 2 - 0.006
   const railY = leafCenterY + panelHeight / 2 - Math.min(frameThickness * 0.35, 0.02)
   const handleY = handleHeight - doorHeight / 2
-  const handleX = activeX + activeSign * (panelWidth / 2 - 0.06)
+  // Active panel + handle ride the SLIDING_ACTIVE_PANEL group, built at the
+  // closed position; `poseDoorMovingParts` slides the group behind the fixed
+  // panel. The fixed panel and rails stay static on the mesh.
+  const handleX = closedActiveX + activeSign * (panelWidth / 2 - 0.06)
 
   currentDoorSlot = 'hardware'
   addBox(
@@ -1804,6 +1896,10 @@ function addSlidingDoor(
     z: number,
   ) => addBox(mesh, material, w, h, d, x + fixedX, y, z + backZ)
 
+  const activePanelGroup = new THREE.Group()
+  activePanelGroup.name = SLIDING_ACTIVE_PANEL_NAME
+  mesh.add(activePanelGroup)
+
   const addActivePanelBox = (
     material: THREE.Material,
     w: number,
@@ -1812,7 +1908,7 @@ function addSlidingDoor(
     x: number,
     y: number,
     z: number,
-  ) => addBox(mesh, material, w, h, d, x + activeX, y, z + frontZ)
+  ) => addBox(activePanelGroup, material, w, h, d, x + closedActiveX, y, z + frontZ)
 
   addLeafSegmentContent({
     addLeafBox: addFixedPanelBox,
@@ -1838,7 +1934,7 @@ function addSlidingDoor(
   })
   currentDoorSlot = 'hardware'
   addBox(
-    mesh,
+    activePanelGroup,
     hardwareMaterial,
     0.032,
     0.24,
@@ -1848,7 +1944,7 @@ function addSlidingDoor(
     frontZ + leafDepth / 2 + 0.01,
   )
   addBox(
-    mesh,
+    activePanelGroup,
     hardwareMaterial,
     0.032,
     0.24,
@@ -1868,7 +1964,6 @@ function addGarageSectionalDoor(
     leafDepth,
     frameThickness,
     frameDepth,
-    operationState,
     garagePanelCount,
   }: {
     insideWidth: number
@@ -1877,19 +1972,13 @@ function addGarageSectionalDoor(
     leafDepth: number
     frameThickness: number
     frameDepth: number
-    operationState: number
     garagePanelCount: number
   },
 ) {
-  const openAmount = getDoorRenderOpenAmount('garage-sectional', operationState)
   const panelCount = Math.max(3, Math.min(12, Math.round(garagePanelCount)))
   const panelHeight = leafHeight / panelCount
   const panelGap = Math.min(0.012, panelHeight * 0.08)
   const travelDepth = Math.max(leafHeight, 1.4)
-  const curveRadius = panelHeight * 0.58
-  const curveLength = (Math.PI / 2) * curveRadius
-  const travel = openAmount * ((panelCount - 1) * panelHeight + curveLength + panelHeight * 0.65)
-  const overheadY = leafCenterY + leafHeight / 2 - panelHeight / 2
   const railY = leafCenterY + leafHeight / 2 - 0.04
   const railZ = -travelDepth / 2
 
@@ -1915,56 +2004,50 @@ function addGarageSectionalDoor(
     railZ,
   )
 
+  // Each panel is built flat (centred at its group origin) and the trims sit on
+  // the panel's front face in local space; `poseDoorMovingParts` rides each
+  // group along the overhead curve. Panel order, geometry and trim placement
+  // match the inline curve math (which the pose function reuses).
+  const revealOffset = (panelHeight - panelGap) * 0.22
+  const trimDepth = 0.01
+  const trimFaceOffset = leafDepth / 2 + trimDepth + 0.006
   for (let index = 0; index < panelCount; index++) {
-    const orderFromTop = panelCount - 1 - index
-    const pathPosition = travel - orderFromTop * panelHeight
-    let y = overheadY + pathPosition
-    let z = 0
-    let rotationX = 0
-
-    if (pathPosition > 0 && pathPosition <= curveLength) {
-      const theta = pathPosition / curveRadius
-      rotationX = -theta
-      y = overheadY + curveRadius * Math.sin(theta)
-      z = -curveRadius * (1 - Math.cos(theta))
-    } else if (pathPosition > curveLength) {
-      rotationX = -Math.PI / 2
-      y = overheadY + curveRadius
-      z = -(curveRadius + pathPosition - curveLength)
-    }
-
-    const revealOffset = (panelHeight - panelGap) * 0.22
-    const trimDepth = 0.01
-    const trimFaceOffset = leafDepth / 2 + trimDepth + 0.006
-    const addSectionalTrim = (localY: number) => {
-      currentDoorSlot = undefined
-      addBoxWithRotation(
-        mesh,
-        revealMaterial,
-        insideWidth - 0.16,
-        0.012,
-        trimDepth,
-        0,
-        y + localY * Math.cos(rotationX) - trimFaceOffset * Math.sin(rotationX),
-        z + localY * Math.sin(rotationX) + trimFaceOffset * Math.cos(rotationX),
-        [rotationX, 0, 0],
-      )
-    }
+    const group = new THREE.Group()
+    group.name = `${SECTIONAL_PANEL_NAME}${index}`
+    mesh.add(group)
 
     currentDoorSlot = 'panel'
-    addBoxWithRotation(
-      mesh,
+    addBox(
+      group,
       baseMaterial,
       insideWidth,
       Math.max(0.04, panelHeight - panelGap),
       leafDepth,
       0,
-      y,
-      z,
-      [rotationX, 0, 0],
+      0,
+      0,
+    )
+    currentDoorSlot = undefined
+    addBox(
+      group,
+      revealMaterial,
+      insideWidth - 0.16,
+      0.012,
+      trimDepth,
+      0,
+      revealOffset,
+      trimFaceOffset,
+    )
+    addBox(
+      group,
+      revealMaterial,
+      insideWidth - 0.16,
+      0.012,
+      trimDepth,
+      0,
+      -revealOffset,
+      trimFaceOffset,
     )
-    addSectionalTrim(revealOffset)
-    addSectionalTrim(-revealOffset)
   }
 
   currentDoorSlot = 'hardware'
@@ -1996,7 +2079,6 @@ function addGarageRollupDoor(
   const visibleHeight = leafHeight * (1 - openAmount)
   const visibleSlatCount = Math.ceil(visibleHeight / slatHeight)
   const topY = leafCenterY + leafHeight / 2
-  const curtainCenterY = topY - visibleHeight / 2
   const drumMaxRadius = Math.max(0.12, Math.min(0.22, leafHeight * 0.075))
   const drumY = topY + drumMaxRadius * 0.12
   const drumZ = -frameDepth / 2 - drumMaxRadius * 0.72
@@ -2024,23 +2106,33 @@ function addGarageRollupDoor(
   )
 
   if (visibleHeight > 0.01) {
+    // Wrap the visible curtain in a group pivoted at the lintel (topY). The live
+    // door keeps rebuilding the full slat detail per `operationState` (this group
+    // is just an organisational wrapper at scale 1 — world positions unchanged),
+    // but it gives the GLB exporter a single node to scale up into the header as
+    // an open clip, since the slats can't literally vanish in a glTF animation.
+    const curtain = new THREE.Group()
+    curtain.name = ROLLUP_CURTAIN_NAME
+    curtain.position.set(0, topY, 0)
+    mesh.add(curtain)
+
     currentDoorSlot = 'panel'
-    addBox(mesh, baseMaterial, insideWidth, visibleHeight, leafDepth, 0, curtainCenterY, 0)
+    addBox(curtain, baseMaterial, insideWidth, visibleHeight, leafDepth, 0, -visibleHeight / 2, 0)
 
     currentDoorSlot = undefined
     for (let index = 0; index < visibleSlatCount; index++) {
-      const y = topY - Math.min(visibleHeight, index * slatHeight)
-      addBox(mesh, revealMaterial, insideWidth - 0.08, 0.01, 0.012, 0, y, leafDepth / 2 + 0.012)
+      const y = -Math.min(visibleHeight, index * slatHeight)
+      addBox(curtain, revealMaterial, insideWidth - 0.08, 0.01, 0.012, 0, y, leafDepth / 2 + 0.012)
     }
 
     addBox(
-      mesh,
+      curtain,
       revealMaterial,
       insideWidth - 0.04,
       0.028,
       leafDepth + 0.018,
       0,
-      topY - visibleHeight,
+      -visibleHeight,
       leafDepth / 2 + 0.004,
     )
   }
@@ -2077,7 +2169,6 @@ function addGarageTiltupDoor(
     leafDepth,
     frameThickness,
     frameDepth,
-    operationState,
   }: {
     insideWidth: number
     leafHeight: number
@@ -2085,14 +2176,12 @@ function addGarageTiltupDoor(
     leafDepth: number
     frameThickness: number
     frameDepth: number
-    operationState: number
   },
 ) {
-  const openAmount = clampDoorOperationState(operationState)
-  const angle = (Math.PI / 2) * openAmount
   const hingeY = leafCenterY + leafHeight / 2
-  const panelCenterY = hingeY - Math.cos(angle) * (leafHeight / 2)
-  const panelCenterZ = -Math.sin(angle) * (leafHeight / 2)
+  // Leaf built closed (hanging from the lintel); `poseDoorMovingParts` rotates
+  // the group about the top hinge to open it. Rails + top bar stay static.
+  const panelCenterY = hingeY - leafHeight / 2
   const railLength = Math.max(leafHeight * 0.72, 1.2)
   const railY = hingeY - frameThickness * 0.35
   const railZ = -railLength / 2
@@ -2119,18 +2208,12 @@ function addGarageTiltupDoor(
     railZ,
   )
 
+  const leafGroup = new THREE.Group()
+  leafGroup.name = TILTUP_LEAF_NAME
+  mesh.add(leafGroup)
+
   currentDoorSlot = 'panel'
-  addBoxWithRotation(
-    mesh,
-    baseMaterial,
-    insideWidth,
-    leafHeight,
-    leafDepth,
-    0,
-    panelCenterY,
-    panelCenterZ,
-    [-angle, 0, 0],
-  )
+  addBox(leafGroup, baseMaterial, insideWidth, leafHeight, leafDepth, 0, panelCenterY, 0)
 
   const insetWidth = Math.max(0.1, insideWidth - 0.22)
   const insetHeight = Math.max(0.1, leafHeight - 0.28)
@@ -2138,16 +2221,15 @@ function addGarageTiltupDoor(
   const trimFaceOffset = leafDepth / 2 + trimDepth + 0.006
   const addTiltupTrim = (localX: number, localY: number, trimWidth: number, trimHeight: number) => {
     currentDoorSlot = undefined
-    addBoxWithRotation(
-      mesh,
+    addBox(
+      leafGroup,
       revealMaterial,
       trimWidth,
       trimHeight,
       trimDepth,
       localX,
-      panelCenterY + localY * Math.cos(angle) + trimFaceOffset * Math.sin(angle),
-      panelCenterZ - localY * Math.sin(angle) + trimFaceOffset * Math.cos(angle),
-      [-angle, 0, 0],
+      panelCenterY + localY,
+      trimFaceOffset,
     )
   }
 
@@ -2368,7 +2450,6 @@ function updateDoorMesh(rawNode: DoorNode, mesh: THREE.Mesh) {
       leafDepth,
       frameThickness,
       frameDepth,
-      operationState,
       garagePanelCount,
     })
   } else if (doorType === 'garage-rollup') {
@@ -2389,7 +2470,6 @@ function updateDoorMesh(rawNode: DoorNode, mesh: THREE.Mesh) {
       leafDepth,
       frameThickness,
       frameDepth,
-      operationState,
     })
   } else if (doorType === 'folding') {
     addFoldingDoor(mesh, {
@@ -2399,7 +2479,6 @@ function updateDoorMesh(rawNode: DoorNode, mesh: THREE.Mesh) {
       leafDepth,
       frameThickness,
       frameDepth,
-      operationState,
       leafCount,
       doorHeight: height,
       handleHeight,
@@ -2414,7 +2493,6 @@ function updateDoorMesh(rawNode: DoorNode, mesh: THREE.Mesh) {
       leafDepth,
       frameThickness,
       frameDepth,
-      operationState,
       slideDirection,
       doorHeight: height,
       handleHeight,
@@ -2429,7 +2507,6 @@ function updateDoorMesh(rawNode: DoorNode, mesh: THREE.Mesh) {
       leafDepth,
       frameThickness,
       frameDepth,
-      operationState,
       slideDirection,
       doorHeight: height,
       handleHeight,
@@ -2444,7 +2521,6 @@ function updateDoorMesh(rawNode: DoorNode, mesh: THREE.Mesh) {
       leafDepth,
       frameThickness,
       frameDepth,
-      operationState,
       slideDirection,
       doorHeight: height,
       handleHeight,
@@ -2549,6 +2625,14 @@ function updateDoorMesh(rawNode: DoorNode, mesh: THREE.Mesh) {
     })
   }
 
+  // Operation doors build their moving parts at the closed pose inside named
+  // groups; reflect the door's current `operationState` by posing them. Roll-up
+  // is excluded: its live rebuild already renders the open state at full detail
+  // (the named curtain group is only there for the GLB exporter's scale clip).
+  if (doorType !== 'garage-rollup') {
+    poseDoorMovingParts(node, mesh, operationState)
+  }
+
   syncDoorCutout(node, mesh)
 
   // Guard: some degenerate door configs can leave a child mesh with an