Fix wall move junction ownership

packages/core/src/index.ts

@@ -107,6 +107,15 @@ export {
   type WallMiterBoundaryPoints,
   type WallMiterData,
 } from './systems/wall/wall-mitering'
+export {
+  constrainWallMoveDeltaToAxis,
+  getPerpendicularWallMoveAxis,
+  planWallMoveJunctions,
+  type WallMoveBridgePlan,
+  type WallMoveAxis,
+  type WallMoveJunctionPlan,
+  type WallPlanPoint,
+} from './systems/wall/wall-move'
 export type { SceneGraph } from './utils/clone-scene-graph'
 export { cloneLevelSubtree, cloneSceneGraph, forkSceneGraph } from './utils/clone-scene-graph'
 export { isObject } from './utils/types'

packages/core/src/store/actions/node-actions.ts

@@ -9,6 +9,9 @@ import type { CollectionId } from '../../schema/collections'
 import type { SceneState } from '../use-scene'
 
 type AnyContainerNode = AnyNode & { children: string[] }
+type NodeCreateOp = { node: AnyNode; parentId?: AnyNodeId }
+type NodeUpdateOp = { id: AnyNodeId; data: Partial<AnyNode> }
+type NodeDeleteOp = AnyNodeId
 type WallAttachmentUpdate = { id: AnyNodeId; data: Partial<AnyNode> }
 type WallMergePlan = {
   primaryWallId: AnyNodeId
@@ -230,7 +233,7 @@ function buildWallMergePlans(
 export const createNodesAction = (
   set: (fn: (state: SceneState) => Partial<SceneState>) => void,
   get: () => SceneState,
-  ops: { node: AnyNode; parentId?: AnyNodeId }[],
+  ops: NodeCreateOp[],
 ) => {
   if (get().readOnly) return
   set((state) => {
@@ -278,6 +281,143 @@ export const createNodesAction = (
   })
 }
 
+export const applyNodeChangesAction = (
+  set: (fn: (state: SceneState) => Partial<SceneState>) => void,
+  get: () => SceneState,
+  changes: { create?: NodeCreateOp[]; update?: NodeUpdateOp[]; delete?: NodeDeleteOp[] },
+) => {
+  if (get().readOnly) return
+
+  const createOps = changes.create ?? []
+  const updateOps = changes.update ?? []
+  const deleteOps = changes.delete ?? []
+  const nodesToMarkDirty = new Set<AnyNodeId>()
+  const parentsToMarkDirty = new Set<AnyNodeId>()
+
+  set((state) => {
+    const nextNodes = { ...state.nodes }
+    const nextCollections = { ...state.collections }
+    const nextRootIds = [...state.rootNodeIds]
+    let resolvedRootIds = nextRootIds
+
+    for (const { id, data } of updateOps) {
+      const currentNode = nextNodes[id]
+      if (!currentNode) continue
+
+      if (data.parentId !== undefined && data.parentId !== currentNode.parentId) {
+        const oldParentId = currentNode.parentId as AnyNodeId | null
+        if (oldParentId && nextNodes[oldParentId]) {
+          const oldParent = nextNodes[oldParentId] as AnyContainerNode
+          nextNodes[oldParent.id] = {
+            ...oldParent,
+            children: oldParent.children.filter((childId) => childId !== id),
+          } as AnyNode
+          parentsToMarkDirty.add(oldParent.id)
+        }
+
+        const newParentId = data.parentId as AnyNodeId | null
+        if (newParentId && nextNodes[newParentId]) {
+          const newParent = nextNodes[newParentId] as AnyContainerNode
+          nextNodes[newParent.id] = {
+            ...newParent,
+            children: Array.from(new Set([...newParent.children, id])),
+          } as AnyNode
+          parentsToMarkDirty.add(newParent.id)
+        }
+      }
+
+      nextNodes[id] = { ...currentNode, ...data } as AnyNode
+      nodesToMarkDirty.add(id)
+    }
+
+    for (const { node, parentId } of createOps) {
+      const effectiveParentId = parentId ?? (node.parentId as AnyNodeId | null) ?? null
+      const newNode = {
+        ...node,
+        parentId: effectiveParentId,
+      } as AnyNode
+
+      nextNodes[newNode.id as AnyNodeId] = newNode
+      nodesToMarkDirty.add(newNode.id as AnyNodeId)
+
+      if (effectiveParentId && nextNodes[effectiveParentId]) {
+        const parent = nextNodes[effectiveParentId]
+        if ('children' in parent && Array.isArray(parent.children)) {
+          nextNodes[effectiveParentId] = {
+            ...parent,
+            children: Array.from(new Set([...parent.children, newNode.id])) as any,
+          }
+          parentsToMarkDirty.add(effectiveParentId)
+        }
+      } else if (!effectiveParentId && !nextRootIds.includes(newNode.id as AnyNodeId)) {
+        nextRootIds.push(newNode.id as AnyNodeId)
+      }
+    }
+
+    const allIdsToDelete = new Set<AnyNodeId>()
+    const collectDelete = (id: AnyNodeId) => {
+      if (allIdsToDelete.has(id)) return
+      allIdsToDelete.add(id)
+      const node = nextNodes[id]
+      if (node && 'children' in node && Array.isArray(node.children)) {
+        for (const childId of node.children) {
+          collectDelete(childId as AnyNodeId)
+        }
+      }
+    }
+
+    for (const id of deleteOps) {
+      collectDelete(id)
+    }
+
+    for (const id of allIdsToDelete) {
+      const node = nextNodes[id]
+      if (!node) continue
+
+      const parentId = node.parentId as AnyNodeId | null
+      if (parentId && nextNodes[parentId] && !allIdsToDelete.has(parentId)) {
+        const parent = nextNodes[parentId] as AnyContainerNode
+        if (parent.children) {
+          nextNodes[parent.id] = {
+            ...parent,
+            children: parent.children.filter((childId) => childId !== id),
+          } as AnyNode
+          parentsToMarkDirty.add(parent.id)
+        }
+      }
+
+      resolvedRootIds = resolvedRootIds.filter((rootId) => rootId !== id)
+
+      if ('collectionIds' in node && node.collectionIds) {
+        for (const collectionId of node.collectionIds as CollectionId[]) {
+          const collection = nextCollections[collectionId]
+          if (collection) {
+            nextCollections[collectionId] = {
+              ...collection,
+              nodeIds: collection.nodeIds.filter((nodeId) => nodeId !== id),
+            }
+          }
+        }
+      }
+
+      delete nextNodes[id]
+    }
+
+    return { nodes: nextNodes, rootNodeIds: resolvedRootIds, collections: nextCollections }
+  })
+
+  nodesToMarkDirty.forEach((id) => get().markDirty(id))
+  parentsToMarkDirty.forEach((id) => {
+    get().markDirty(id)
+    const parent = get().nodes[id]
+    if (parent && 'children' in parent && Array.isArray(parent.children)) {
+      for (const childId of parent.children) {
+        get().markDirty(childId as AnyNodeId)
+      }
+    }
+  })
+}
+
 export const updateNodesAction = (
   set: (fn: (state: SceneState) => Partial<SceneState>) => void,
   get: () => SceneState,

packages/core/src/store/use-scene.ts

@@ -438,6 +438,11 @@ export type SceneState = {
 
   createNode: (node: AnyNode, parentId?: AnyNodeId) => void
   createNodes: (ops: { node: AnyNode; parentId?: AnyNodeId }[]) => void
+  applyNodeChanges: (changes: {
+    create?: { node: AnyNode; parentId?: AnyNodeId }[]
+    update?: { id: AnyNodeId; data: Partial<AnyNode> }[]
+    delete?: AnyNodeId[]
+  }) => void
 
   updateNode: (id: AnyNodeId, data: Partial<AnyNode>) => void
   updateNodes: (updates: { id: AnyNodeId; data: Partial<AnyNode> }[]) => void
@@ -579,6 +584,7 @@ const useScene: UseSceneStore = create<SceneState>()(
 
       createNodes: (ops) => nodeActions.createNodesAction(set, get, ops),
       createNode: (node, parentId) => nodeActions.createNodesAction(set, get, [{ node, parentId }]),
+      applyNodeChanges: (changes) => nodeActions.applyNodeChangesAction(set, get, changes),
 
       updateNodes: (updates) => nodeActions.updateNodesAction(set, get, updates),
       updateNode: (id, data) => nodeActions.updateNodesAction(set, get, [{ id, data }]),

packages/core/src/systems/wall/wall-move.ts

@@ -0,0 +1,227 @@
+import type { WallNode } from '../../schema'
+
+const AXIS_EPSILON = 1e-6
+
+export type WallPlanPoint = [number, number]
+export type WallMoveAxis = 'x' | 'z'
+export type WallMoveEndpoint = 'start' | 'end'
+
+export type WallMoveBridgePlan<TWall extends Pick<WallNode, 'id' | 'start' | 'end'>> = {
+  wall: TWall
+  originalPoint: WallPlanPoint
+  movedEndpoint: WallMoveEndpoint
+}
+
+export type WallMoveLinkedWallTargetPlan<
+  TWall extends Pick<WallNode, 'id' | 'start' | 'end'>,
+> = {
+  wall: TWall
+  originalPoint: WallPlanPoint
+  targetPoint: WallPlanPoint
+}
+
+export type WallMoveJunctionPlan<TWall extends Pick<WallNode, 'id' | 'start' | 'end'>> = {
+  linkedWallsToMove: TWall[]
+  linkedWallTargetPlans: Array<WallMoveLinkedWallTargetPlan<TWall>>
+  bridgePlans: Array<WallMoveBridgePlan<TWall>>
+  wallsToDelete: TWall[]
+}
+
+export function getPerpendicularWallMoveAxis(
+  start: WallPlanPoint,
+  end: WallPlanPoint,
+): WallMoveAxis | null {
+  const wallDeltaX = Math.abs(end[0] - start[0])
+  const wallDeltaZ = Math.abs(end[1] - start[1])
+
+  if (wallDeltaX < AXIS_EPSILON && wallDeltaZ < AXIS_EPSILON) return null
+
+  return wallDeltaX >= wallDeltaZ ? 'z' : 'x'
+}
+
+export function constrainWallMoveDeltaToAxis(
+  deltaX: number,
+  deltaZ: number,
+  axis: WallMoveAxis | null,
+): WallPlanPoint {
+  if (axis === 'x') return [deltaX, 0]
+  if (axis === 'z') return [0, deltaZ]
+  return [deltaX, deltaZ]
+}
+
+function pointsEqual(a: WallPlanPoint, b: WallPlanPoint) {
+  return Math.abs(a[0] - b[0]) <= AXIS_EPSILON && Math.abs(a[1] - b[1]) <= AXIS_EPSILON
+}
+
+function wallTouchesPoint(wall: Pick<WallNode, 'start' | 'end'>, point: WallPlanPoint) {
+  return pointsEqual(wall.start, point) || pointsEqual(wall.end, point)
+}
+
+function otherWallEndpoint(wall: Pick<WallNode, 'start' | 'end'>, point: WallPlanPoint) {
+  return pointsEqual(wall.start, point) ? wall.end : wall.start
+}
+
+type MoveWallRelation = 'same-direction' | 'opposite-direction' | 'off-axis' | 'stationary'
+type RelatedWallEntry<TWall extends Pick<WallNode, 'id' | 'start' | 'end'>> = {
+  wall: TWall
+  relation: MoveWallRelation
+}
+
+function wallLengthFromPoint(wall: Pick<WallNode, 'start' | 'end'>, point: WallPlanPoint) {
+  const freeEndpoint = otherWallEndpoint(wall, point)
+  return Math.hypot(freeEndpoint[0] - point[0], freeEndpoint[1] - point[1])
+}
+
+function getMoveWallRelation(
+  wall: Pick<WallNode, 'start' | 'end'>,
+  sharedPoint: WallPlanPoint,
+  nextPoint: WallPlanPoint,
+): MoveWallRelation {
+  const moveX = nextPoint[0] - sharedPoint[0]
+  const moveZ = nextPoint[1] - sharedPoint[1]
+  const moveLength = Math.hypot(moveX, moveZ)
+
+  if (moveLength < AXIS_EPSILON) return 'stationary'
+
+  const freeEndpoint = otherWallEndpoint(wall, sharedPoint)
+  const wallX = freeEndpoint[0] - sharedPoint[0]
+  const wallZ = freeEndpoint[1] - sharedPoint[1]
+  const wallLength = Math.hypot(wallX, wallZ)
+
+  if (wallLength < AXIS_EPSILON) return 'stationary'
+
+  const normalizedCross = Math.abs(moveX * wallZ - moveZ * wallX) / (moveLength * wallLength)
+  if (normalizedCross > 1e-4) return 'off-axis'
+
+  const normalizedDot = (moveX * wallX + moveZ * wallZ) / (moveLength * wallLength)
+  return normalizedDot >= 0 ? 'same-direction' : 'opposite-direction'
+}
+
+export function planWallMoveJunctions<TWall extends Pick<WallNode, 'id' | 'start' | 'end'>>(
+  linkedWalls: TWall[],
+  originalStart: WallPlanPoint,
+  originalEnd: WallPlanPoint,
+  nextStart: WallPlanPoint,
+  nextEnd: WallPlanPoint,
+): WallMoveJunctionPlan<TWall> {
+  const linkedWallsToMove = new Map<TWall['id'], TWall>()
+  const linkedWallTargetPlans = new Map<TWall['id'], WallMoveLinkedWallTargetPlan<TWall>>()
+  const bridgePlans = new Map<string, WallMoveBridgePlan<TWall>>()
+  const wallsToDelete = new Map<TWall['id'], TWall>()
+
+  const addStandardEndpointPlan = (
+    endpoint: WallMoveEndpoint,
+    point: WallPlanPoint,
+    nextPoint: WallPlanPoint,
+    relatedWalls: Array<RelatedWallEntry<TWall>>,
+    keySuffix = '',
+    useTargetPlans = false,
+  ) => {
+    const hasSideBranch = relatedWalls.some((entry) => entry.relation === 'off-axis')
+    const hasOppositeBridge = relatedWalls.some(
+      (entry) => entry.relation === 'opposite-direction' && hasSideBranch,
+    )
+
+    for (const { wall, relation } of relatedWalls) {
+      if (
+        relation === 'stationary' ||
+        relation === 'same-direction' ||
+        (relation === 'opposite-direction' && !hasSideBranch)
+      ) {
+        if (useTargetPlans) {
+          linkedWallTargetPlans.set(wall.id, {
+            wall,
+            originalPoint: point,
+            targetPoint: nextPoint,
+          })
+        } else {
+          linkedWallsToMove.set(wall.id, wall)
+        }
+        continue
+      }
+
+      if (relation === 'off-axis' && hasOppositeBridge) {
+        continue
+      }
+
+      bridgePlans.set(`${wall.id}:${endpoint}${keySuffix}`, {
+        wall,
+        originalPoint: point,
+        movedEndpoint: endpoint,
+      })
+    }
+  }
+
+  const addEndpointPlan = (
+    endpoint: WallMoveEndpoint,
+    point: WallPlanPoint,
+    nextPoint: WallPlanPoint,
+  ) => {
+    const moveLength = Math.hypot(nextPoint[0] - point[0], nextPoint[1] - point[1])
+    const linkedAtEndpoint = linkedWalls
+      .filter((wall) => wallTouchesPoint(wall, point))
+      .map((wall) => ({
+        wall,
+        relation: getMoveWallRelation(wall, point, nextPoint),
+      }))
+    const consumedSameDirectionWall = linkedAtEndpoint
+      .filter((entry) => entry.relation === 'same-direction')
+      .map((entry) => ({
+        ...entry,
+        distance: wallLengthFromPoint(entry.wall, point),
+      }))
+      .filter((entry) => moveLength + AXIS_EPSILON >= entry.distance)
+      .sort((a, b) => a.distance - b.distance)[0]
+
+    if (consumedSameDirectionWall) {
+      const pivotPoint = [...otherWallEndpoint(consumedSameDirectionWall.wall, point)] as WallPlanPoint
+      const bridgeSource = linkedAtEndpoint.find((entry) => entry.relation === 'opposite-direction')
+
+      wallsToDelete.set(consumedSameDirectionWall.wall.id, consumedSameDirectionWall.wall)
+      linkedWallTargetPlans.set(consumedSameDirectionWall.wall.id, {
+        wall: consumedSameDirectionWall.wall,
+        originalPoint: point,
+        targetPoint: pivotPoint,
+      })
+
+      if (bridgeSource) {
+        linkedWallTargetPlans.set(bridgeSource.wall.id, {
+          wall: bridgeSource.wall,
+          originalPoint: point,
+          targetPoint: pivotPoint,
+        })
+
+        bridgePlans.set(`${bridgeSource.wall.id}:${endpoint}:through`, {
+          wall: bridgeSource.wall,
+          originalPoint: pivotPoint,
+          movedEndpoint: endpoint,
+        })
+        return
+      }
+
+      const linkedAtPivot = linkedWalls
+        .filter(
+          (wall) => wall.id !== consumedSameDirectionWall.wall.id && wallTouchesPoint(wall, pivotPoint),
+        )
+        .map((wall) => ({
+          wall,
+          relation: getMoveWallRelation(wall, pivotPoint, nextPoint),
+        }))
+
+      addStandardEndpointPlan(endpoint, pivotPoint, nextPoint, linkedAtPivot, ':through-pivot', true)
+      return
+    }
+
+    addStandardEndpointPlan(endpoint, point, nextPoint, linkedAtEndpoint)
+  }
+
+  addEndpointPlan('start', originalStart, nextStart)
+  addEndpointPlan('end', originalEnd, nextEnd)
+
+  return {
+    linkedWallsToMove: Array.from(linkedWallsToMove.values()),
+    linkedWallTargetPlans: Array.from(linkedWallTargetPlans.values()),
+    bridgePlans: Array.from(bridgePlans.values()),
+    wallsToDelete: Array.from(wallsToDelete.values()),
+  }
+}

packages/editor/src/components/editor/selection-manager.tsx

@@ -1636,6 +1636,7 @@ const EditorOutlinerSync = () => {
   const previewSelectedIds = useViewer((s) => s.previewSelectedIds)
   const hoveredId = useViewer((s) => s.hoveredId)
   const outliner = useViewer((s) => s.outliner)
+  const nodes = useScene((s) => s.nodes)
 
   useEffect(() => {
     let idsToHighlight: string[] = []
@@ -1672,16 +1673,21 @@ const EditorOutlinerSync = () => {
     // 2. Sync with the imperative outliner arrays (mutate in place to keep references)
     outliner.selectedObjects.length = 0
     for (const id of idsToHighlight) {
+      if (!nodes[id as AnyNodeId]) continue
       const obj = sceneRegistry.nodes.get(id)
       if (obj?.parent) outliner.selectedObjects.push(obj)
     }
 
     outliner.hoveredObjects.length = 0
     if (hoveredId) {
-      const obj = sceneRegistry.nodes.get(hoveredId)
-      if (obj?.parent) outliner.hoveredObjects.push(obj)
+      if (!nodes[hoveredId as AnyNodeId]) {
+        useViewer.setState({ hoveredId: null })
+      } else {
+        const obj = sceneRegistry.nodes.get(hoveredId)
+        if (obj?.parent) outliner.hoveredObjects.push(obj)
+      }
     }
-  }, [phase, previewSelectedIds, selection, hoveredId, outliner])
+  }, [phase, previewSelectedIds, selection, hoveredId, outliner, nodes])
 
   return null
 }

packages/editor/src/components/tools/wall/move-wall-tool.tsx

@@ -2,12 +2,19 @@
 
 import {
   type AnyNodeId,
+  constrainWallMoveDeltaToAxis,
   emitter,
+  getPerpendicularWallMoveAxis,
   type GridEvent,
   pauseSceneHistory,
+  planWallMoveJunctions,
   resumeSceneHistory,
   useScene,
+  type WallMoveBridgePlan,
+  type WallMoveAxis,
+  type WallMoveJunctionPlan,
   type WallNode,
+  WallNode as WallSchema,
 } from '@pascal-app/core'
 import { useViewer } from '@pascal-app/viewer'
 import { useCallback, useEffect, useRef, useState } from 'react'
@@ -15,7 +22,7 @@ import { markToolCancelConsumed } from '../../../hooks/use-keyboard'
 import { sfxEmitter } from '../../../lib/sfx-bus'
 import useEditor from '../../../store/use-editor'
 import { CursorSphere } from '../shared/cursor-sphere'
-import { getWallGridStep, snapScalarToGrid } from './wall-drafting'
+import { getWallGridStep, isWallLongEnough, snapScalarToGrid } from './wall-drafting'
 
 function rotateVector([x, z]: [number, number], angle: number): [number, number] {
   const cos = Math.cos(angle)
@@ -27,6 +34,10 @@ function samePoint(a: [number, number], b: [number, number]) {
   return a[0] === b[0] && a[1] === b[1]
 }
 
+function pointKey(point: [number, number]) {
+  return `${point[0]}:${point[1]}`
+}
+
 function stripWallIsNewMetadata(meta: WallNode['metadata']): WallNode['metadata'] {
   if (!meta || typeof meta !== 'object' || Array.isArray(meta)) {
     return meta
@@ -37,11 +48,7 @@ function stripWallIsNewMetadata(meta: WallNode['metadata']): WallNode['metadata'
   return nextMeta as WallNode['metadata']
 }
 
-type LinkedWallSnapshot = {
-  id: WallNode['id']
-  start: [number, number]
-  end: [number, number]
-}
+type LinkedWallSnapshot = WallNode
 
 function getLinkedWallSnapshots(args: {
   wallId: WallNode['id']
@@ -51,30 +58,45 @@ function getLinkedWallSnapshots(args: {
 }) {
   const { wallId, wallParentId, originalStart, originalEnd } = args
   const { nodes } = useScene.getState()
+  const walls = Object.values(nodes).filter(
+    (node): node is WallNode =>
+      node?.type === 'wall' && node.id !== wallId && (node.parentId ?? null) === wallParentId,
+  )
+  const directlyLinkedWalls = walls.filter(
+    (wall) =>
+      samePoint(wall.start, originalStart) ||
+      samePoint(wall.start, originalEnd) ||
+      samePoint(wall.end, originalStart) ||
+      samePoint(wall.end, originalEnd),
+  )
+  const contextPoints = new Set([pointKey(originalStart), pointKey(originalEnd)])
+
+  for (const wall of directlyLinkedWalls) {
+    contextPoints.add(pointKey(wall.start))
+    contextPoints.add(pointKey(wall.end))
+  }
+
   const snapshots: LinkedWallSnapshot[] = []
+  const seenWallIds = new Set<WallNode['id']>()
 
-  for (const node of Object.values(nodes)) {
-    if (!(node?.type === 'wall' && node.id !== wallId)) {
-      continue
-    }
-
-    if ((node.parentId ?? null) !== wallParentId) {
-      continue
-    }
-
+  for (const node of walls) {
     if (
-      !samePoint(node.start, originalStart) &&
-      !samePoint(node.start, originalEnd) &&
-      !samePoint(node.end, originalStart) &&
-      !samePoint(node.end, originalEnd)
+      !contextPoints.has(pointKey(node.start)) &&
+      !contextPoints.has(pointKey(node.end))
     ) {
       continue
     }
 
+    if (seenWallIds.has(node.id)) {
+      continue
+    }
+    seenWallIds.add(node.id)
+
     snapshots.push({
-      id: node.id,
+      ...node,
       start: [...node.start] as [number, number],
       end: [...node.end] as [number, number],
+      children: [...(node.children ?? [])],
     })
   }
 
@@ -82,25 +104,139 @@ function getLinkedWallSnapshots(args: {
 }
 
 function getLinkedWallUpdates(
-  linkedWalls: LinkedWallSnapshot[],
+  linkedWalls: Array<{
+    wall: LinkedWallSnapshot
+    matchPoint?: [number, number]
+    targetPoint?: [number, number]
+  }>,
   originalStart: [number, number],
   originalEnd: [number, number],
   nextStart: [number, number],
   nextEnd: [number, number],
 ) {
-  return linkedWalls.map((wall) => ({
-    id: wall.id,
-    start: samePoint(wall.start, originalStart)
-      ? nextStart
-      : samePoint(wall.start, originalEnd)
-        ? nextEnd
-        : wall.start,
-    end: samePoint(wall.end, originalStart)
-      ? nextStart
-      : samePoint(wall.end, originalEnd)
-        ? nextEnd
-        : wall.end,
-  }))
+  return linkedWalls.map(({ wall, matchPoint, targetPoint }) => {
+    if (matchPoint && targetPoint) {
+      return {
+        id: wall.id,
+        start: samePoint(wall.start, matchPoint) ? targetPoint : wall.start,
+        end: samePoint(wall.end, matchPoint) ? targetPoint : wall.end,
+      }
+    }
+
+    const targetStart = targetPoint ?? nextStart
+    const targetEnd = targetPoint ?? nextEnd
+
+    return {
+      id: wall.id,
+      start: samePoint(wall.start, originalStart)
+        ? targetStart
+        : samePoint(wall.start, originalEnd)
+          ? targetEnd
+          : wall.start,
+      end: samePoint(wall.end, originalStart)
+        ? targetStart
+        : samePoint(wall.end, originalEnd)
+          ? targetEnd
+          : wall.end,
+    }
+  })
+}
+
+function getPlannedLinkedWallUpdates(
+  plan: WallMoveJunctionPlan<LinkedWallSnapshot>,
+  originalStart: [number, number],
+  originalEnd: [number, number],
+  nextStart: [number, number],
+  nextEnd: [number, number],
+) {
+  const movePlans = new Map<
+    WallNode['id'],
+    { wall: LinkedWallSnapshot; matchPoint?: [number, number]; targetPoint?: [number, number] }
+  >()
+
+  for (const wall of plan.linkedWallsToMove) {
+    movePlans.set(wall.id, { wall })
+  }
+
+  for (const targetPlan of plan.linkedWallTargetPlans) {
+    movePlans.set(targetPlan.wall.id, {
+      wall: targetPlan.wall,
+      matchPoint: targetPlan.originalPoint,
+      targetPoint: targetPlan.targetPoint,
+    })
+  }
+
+  return getLinkedWallUpdates(
+    Array.from(movePlans.values()),
+    originalStart,
+    originalEnd,
+    nextStart,
+    nextEnd,
+  )
+}
+
+function wallSegmentExists(walls: WallNode[], start: [number, number], end: [number, number]) {
+  return walls.some(
+    (wall) =>
+      (samePoint(wall.start, start) && samePoint(wall.end, end)) ||
+      (samePoint(wall.start, end) && samePoint(wall.end, start)),
+  )
+}
+
+function getWallsAfterUpdates(
+  nodes: ReturnType<typeof useScene.getState>['nodes'],
+  updates: Array<{ id: AnyNodeId; data: Partial<WallNode> }>,
+) {
+  const updateById = new Map(updates.map((update) => [update.id, update.data]))
+
+  return Object.values(nodes)
+    .filter((node): node is WallNode => node?.type === 'wall')
+    .map((wall) => {
+      const update = updateById.get(wall.id as AnyNodeId)
+      return update ? ({ ...wall, ...update } as WallNode) : wall
+    })
+}
+
+function buildBridgeWallCreates(args: {
+  bridgePlans: Array<WallMoveBridgePlan<LinkedWallSnapshot>>
+  nextStart: [number, number]
+  nextEnd: [number, number]
+  existingWalls: WallNode[]
+  wallCount: number
+}): Array<{ node: WallNode; parentId?: AnyNodeId }> {
+  const { bridgePlans, nextStart, nextEnd, existingWalls, wallCount } = args
+  const wallsForDuplicateCheck = [...existingWalls]
+  const creates: Array<{ node: WallNode; parentId?: AnyNodeId }> = []
+
+  for (const plan of bridgePlans) {
+    const nextPoint = plan.movedEndpoint === 'start' ? nextStart : nextEnd
+
+    if (!isWallLongEnough(plan.originalPoint, nextPoint)) {
+      continue
+    }
+
+    if (wallSegmentExists(wallsForDuplicateCheck, plan.originalPoint, nextPoint)) {
+      continue
+    }
+
+    const { id: _id, parentId: _parentId, children: _children, ...sourceWall } = plan.wall
+    const bridgeWall = WallSchema.parse({
+      ...sourceWall,
+      name: `Wall ${wallCount + creates.length + 1}`,
+      start: plan.originalPoint,
+      end: nextPoint,
+      children: [],
+      metadata: stripWallIsNewMetadata(plan.wall.metadata),
+    })
+
+    creates.push({
+      node: bridgeWall,
+      parentId: (plan.wall.parentId ?? undefined) as AnyNodeId | undefined,
+    })
+    wallsForDuplicateCheck.push(bridgeWall)
+  }
+
+  return creates
 }
 
 export const MoveWallTool: React.FC<{ node: WallNode }> = ({ node }) => {
@@ -121,7 +257,10 @@ export const MoveWallTool: React.FC<{ node: WallNode }> = ({ node }) => {
     (node.end[0] - node.start[0]) / 2,
     (node.end[1] - node.start[1]) / 2,
   ])
-  const linkedOriginalsRef = useRef(
+  const moveAxisRef = useRef<WallMoveAxis | null>(
+    getPerpendicularWallMoveAxis(node.start, node.end),
+  )
+  const linkedOriginalsRef = useRef<LinkedWallSnapshot[]>(
     isNew
       ? []
       : getLinkedWallSnapshots({
@@ -178,6 +317,31 @@ export const MoveWallTool: React.FC<{ node: WallNode }> = ({ node }) => {
       return { start: nextStart, end: nextEnd }
     }
 
+    const getMovePlan = (nextStart: [number, number], nextEnd: [number, number]) =>
+      planWallMoveJunctions(
+        linkedOriginalsRef.current,
+        originalStart,
+        originalEnd,
+        nextStart,
+        nextEnd,
+      )
+
+    const getLinkedPreviewUpdates = (nextStart: [number, number], nextEnd: [number, number]) => {
+      const plan = getMovePlan(nextStart, nextEnd)
+      const movedUpdates = getPlannedLinkedWallUpdates(
+        plan,
+        originalStart,
+        originalEnd,
+        nextStart,
+        nextEnd,
+      )
+      const movedById = new Map(movedUpdates.map((entry) => [entry.id, entry]))
+
+      return linkedOriginalsRef.current.map(
+        (wall) => movedById.get(wall.id) ?? { id: wall.id, start: wall.start, end: wall.end },
+      )
+    }
+
     const applyPreview = (nextStart: [number, number], nextEnd: [number, number]) => {
       previewRef.current = { start: nextStart, end: nextEnd }
       const centerX = (nextStart[0] + nextEnd[0]) / 2
@@ -185,13 +349,7 @@ export const MoveWallTool: React.FC<{ node: WallNode }> = ({ node }) => {
       setCursorLocalPos([centerX, 0, centerZ])
       applyNodePreview([
         { id: nodeId, start: nextStart, end: nextEnd },
-        ...getLinkedWallUpdates(
-          linkedOriginalsRef.current,
-          originalStart,
-          originalEnd,
-          nextStart,
-          nextEnd,
-        ),
+        ...getLinkedPreviewUpdates(nextStart, nextEnd),
       ])
     }
 
@@ -209,19 +367,24 @@ export const MoveWallTool: React.FC<{ node: WallNode }> = ({ node }) => {
       const localX = shiftPressedRef.current ? rawX : snapScalarToGrid(rawX, snapStep)
       const localZ = shiftPressedRef.current ? rawZ : snapScalarToGrid(rawZ, snapStep)
 
-      if (
-        previousGridPosRef.current &&
-        (localX !== previousGridPosRef.current[0] || localZ !== previousGridPosRef.current[1])
-      ) {
-        sfxEmitter.emit('sfx:grid-snap')
-      }
-      previousGridPosRef.current = [localX, localZ]
-
       const anchor = dragAnchorRef.current ?? [localX, localZ]
       dragAnchorRef.current = anchor
 
-      const deltaX = localX - anchor[0]
-      const deltaZ = localZ - anchor[1]
+      const [deltaX, deltaZ] = constrainWallMoveDeltaToAxis(
+        localX - anchor[0],
+        localZ - anchor[1],
+        moveAxisRef.current,
+      )
+      const constrainedGridPos: [number, number] = [anchor[0] + deltaX, anchor[1] + deltaZ]
+
+      if (
+        previousGridPosRef.current &&
+        (constrainedGridPos[0] !== previousGridPosRef.current[0] ||
+          constrainedGridPos[1] !== previousGridPosRef.current[1])
+      ) {
+        sfxEmitter.emit('sfx:grid-snap')
+      }
+      previousGridPosRef.current = constrainedGridPos
 
       const nextCenter: [number, number] = [originalCenter[0] + deltaX, originalCenter[1] + deltaZ]
       const nextWall = buildWallFromCenter(nextCenter)
@@ -246,6 +409,22 @@ export const MoveWallTool: React.FC<{ node: WallNode }> = ({ node }) => {
       ])
 
       resumeSceneHistory(useScene)
+      const commitPlan = getMovePlan(preview.start, preview.end)
+      const linkedWallUpdates = getPlannedLinkedWallUpdates(
+        commitPlan,
+        originalStart,
+        originalEnd,
+        preview.start,
+        preview.end,
+      )
+      const collapsedLinkedWallIds = new Set(
+        [
+          ...linkedWallUpdates
+            .filter((entry) => !isWallLongEnough(entry.start, entry.end))
+            .map((entry) => entry.id as AnyNodeId),
+          ...commitPlan.wallsToDelete.map((wall) => wall.id as AnyNodeId),
+        ],
+      )
 
       const commitUpdates = [
         {
@@ -258,21 +437,30 @@ export const MoveWallTool: React.FC<{ node: WallNode }> = ({ node }) => {
               }
             : { start: preview.start, end: preview.end },
         },
-        ...getLinkedWallUpdates(
-          linkedOriginalsRef.current,
-          originalStart,
-          originalEnd,
-          preview.start,
-          preview.end,
-        ).map((entry) => ({
-          id: entry.id as AnyNodeId,
-          data: { start: entry.start, end: entry.end },
-        })),
+        ...linkedWallUpdates
+          .filter((entry) => !collapsedLinkedWallIds.has(entry.id as AnyNodeId))
+          .map((entry) => ({
+            id: entry.id as AnyNodeId,
+            data: { start: entry.start, end: entry.end },
+          })),
       ]
-      useScene.getState().updateNodes(commitUpdates)
-      for (const { id } of commitUpdates) {
-        useScene.getState().markDirty(id)
-      }
+      const sceneState = useScene.getState()
+      const existingWalls = getWallsAfterUpdates(sceneState.nodes, commitUpdates).filter(
+        (wall) => !collapsedLinkedWallIds.has(wall.id as AnyNodeId),
+      )
+      const bridgeCreates = buildBridgeWallCreates({
+        bridgePlans: commitPlan.bridgePlans,
+        nextStart: preview.start,
+        nextEnd: preview.end,
+        existingWalls,
+        wallCount: Object.values(sceneState.nodes).filter((entry) => entry?.type === 'wall')
+          .length,
+      })
+      sceneState.applyNodeChanges({
+        update: commitUpdates,
+        create: bridgeCreates,
+        delete: Array.from(collapsedLinkedWallIds),
+      })
 
       pauseSceneHistory(useScene)
 
@@ -311,6 +499,7 @@ export const MoveWallTool: React.FC<{ node: WallNode }> = ({ node }) => {
         (preview.start[1] + preview.end[1]) / 2,
       ]
       const nextWall = buildWallFromCenter(currentCenter)
+      moveAxisRef.current = getPerpendicularWallMoveAxis(nextWall.start, nextWall.end)
       applyPreview(nextWall.start, nextWall.end)
     }
 

packages/viewer/src/components/renderers/item/item-renderer.tsx

@@ -156,9 +156,12 @@ const ModelRenderer = ({ node }: { node: ItemNode }) => {
   const lightEffects =
     interactive?.effects.filter((e): e is LightEffect => e.kind === 'light') ?? []
 
+  // useGLTF caches scenes, and Clone shares child geometry/material references.
+  // Undo can unmount one item while another clone of the same asset still needs them.
   return (
     <>
       <Clone
+        dispose={null}
         object={scene}
         position={node.asset.offset}
         ref={ref}

packages/viewer/src/components/renderers/wall/wall-renderer.tsx

@@ -1,12 +1,27 @@
 import { useRegistry, useScene, type WallNode } from '@pascal-app/core'
-import { useLayoutEffect, useRef } from 'react'
-import type { Mesh } from 'three'
+import { useEffect, useLayoutEffect, useMemo, useRef } from 'react'
+import { BufferGeometry, Float32BufferAttribute, type Mesh } from 'three'
 import { useNodeEvents } from '../../../hooks/use-node-events'
 import { getVisibleWallMaterials } from '../../../systems/wall/wall-materials'
 import { NodeRenderer } from '../node-renderer'
 
+function createEmptyWallGeometry() {
+  const geometry = new BufferGeometry()
+  geometry.setAttribute('position', new Float32BufferAttribute([], 3))
+  geometry.addGroup(0, 0, 0)
+  geometry.addGroup(0, 0, 1)
+  geometry.addGroup(0, 0, 2)
+  return geometry
+}
+
 export const WallRenderer = ({ node }: { node: WallNode }) => {
   const ref = useRef<Mesh>(null!)
+  const placeholderGeometry = useMemo(createEmptyWallGeometry, [])
+  const collisionPlaceholderGeometry = useMemo(() => {
+    const geometry = new BufferGeometry()
+    geometry.setAttribute('position', new Float32BufferAttribute([], 3))
+    return geometry
+  }, [])
 
   useRegistry(node.id, 'wall', ref)
 
@@ -14,15 +29,31 @@ export const WallRenderer = ({ node }: { node: WallNode }) => {
     useScene.getState().markDirty(node.id)
   }, [node.id])
 
+  useEffect(() => {
+    return () => {
+      placeholderGeometry.dispose()
+      collisionPlaceholderGeometry.dispose()
+    }
+  }, [collisionPlaceholderGeometry, placeholderGeometry])
+
   const handlers = useNodeEvents(node, 'wall')
   const material = getVisibleWallMaterials(node)
 
   return (
-    <mesh castShadow material={material} receiveShadow ref={ref} visible={node.visible}>
-      <boxGeometry args={[0, 0, 0]} />
-      <mesh name="collision-mesh" visible={false} {...handlers}>
-        <boxGeometry args={[0, 0, 0]} />
-      </mesh>
+    <mesh
+      castShadow
+      geometry={placeholderGeometry}
+      material={material}
+      receiveShadow
+      ref={ref}
+      visible={node.visible}
+    >
+      <mesh
+        geometry={collisionPlaceholderGeometry}
+        name="collision-mesh"
+        visible={false}
+        {...handlers}
+      />
 
       {node.children.map((childId) => (
         <NodeRenderer key={`${node.id}:${childId}`} nodeId={childId} />

packages/viewer/src/lib/materials.ts

@@ -271,16 +271,18 @@ export function createMaterial(material?: MaterialSchema): THREE.MeshStandardMat
   }
 
   const map = getTexture(material)
-
-  const threeMaterial = new THREE.MeshStandardMaterial({
+  const materialParams: THREE.MeshStandardMaterialParameters = {
     color: props.color,
     roughness: props.roughness,
     metalness: props.metalness,
     opacity: props.opacity,
     transparent: props.transparent,
     side: sideMap[props.side],
-    map,
-  })
+  }
+
+  if (map) materialParams.map = map
+
+  const threeMaterial = new THREE.MeshStandardMaterial(materialParams)
 
   materialCache.set(cacheKey, threeMaterial)
   return threeMaterial