Merge pull request #84 from pascalorg/feat/flood-fill-wall-cut

Feat/flood fill wall cut

apps/editor/app/viewer/[id]/viewer-overlay.tsx

@@ -21,6 +21,7 @@ export const ViewerOverlay = () => {
   const showGuides = useViewer((s) => s.showGuides)
   const cameraMode = useViewer((s) => s.cameraMode)
   const levelMode = useViewer((s) => s.levelMode)
+  const wallMode = useViewer((s) => s.wallMode)
 
   const building = selection.buildingId ? (nodes[selection.buildingId] as BuildingNode | undefined) : null
   const level = selection.levelId ? (nodes[selection.levelId] as LevelNode | undefined) : null
@@ -202,6 +203,38 @@ export const ViewerOverlay = () => {
           Solo
         </button>
       </div>
+
+      {/* Wall Mode */}
+      <div className="flex flex-col gap-1 bg-white/80 backdrop-blur-sm rounded-lg p-2 shadow-sm border border-neutral-200">
+        <span className="text-xs text-neutral-500 px-2 pb-1">Wall Mode</span>
+        <button
+          onClick={() => useViewer.getState().setWallMode('cutaway')}
+          className={`flex items-center gap-2 px-2 py-1 rounded text-sm transition-colors ${
+            wallMode === 'cutaway' ? 'bg-blue-500 text-white' : 'text-neutral-700 hover:bg-neutral-100'
+          }`}
+        >
+          <img alt="Cutaway" height={16} src="/icons/wallcut.png" width={16} className="w-4 h-4" />
+          Cutaway
+        </button>
+        <button
+          onClick={() => useViewer.getState().setWallMode('up')}
+          className={`flex items-center gap-2 px-2 py-1 rounded text-sm transition-colors ${
+            wallMode === 'up' ? 'bg-blue-500 text-white' : 'text-neutral-700 hover:bg-neutral-100'
+          }`}
+        >
+          <img alt="Full Height" height={16} src="/icons/room.png" width={16} className="w-4 h-4" />
+          Full Height
+        </button>
+        <button
+          onClick={() => useViewer.getState().setWallMode('down')}
+          className={`flex items-center gap-2 px-2 py-1 rounded text-sm transition-colors ${
+            wallMode === 'down' ? 'bg-blue-500 text-white' : 'text-neutral-700 hover:bg-neutral-100'
+          }`}
+        >
+          <img alt="Low" height={16} src="/icons/walllow.png" width={16} className="w-4 h-4" />
+          Low
+        </button>
+      </div>
     </div>
     </>
   )

apps/editor/components/editor/index.tsx

@@ -1,6 +1,11 @@
 'use client'
 
-import { initSpatialGridSync, sceneRegistry, useScene } from '@pascal-app/core'
+import {
+  initSpaceDetectionSync,
+  initSpatialGridSync,
+  sceneRegistry,
+  useScene,
+} from '@pascal-app/core'
 import { useGridEvents, useViewer, Viewer } from '@pascal-app/viewer'
 
 import { useFrame } from '@react-three/fiber'
@@ -10,6 +15,7 @@ import { MathUtils, type Mesh } from 'three'
 import { color, float, fract, fwidth, mix, positionLocal } from 'three/tsl'
 import { MeshBasicNodeMaterial } from 'three/webgpu'
 import { useKeyboard } from '@/hooks/use-keyboard'
+import useEditor from '@/store/use-editor'
 import { ZoneSystem } from '../systems/zone/zone-system'
 import { ToolManager } from '../tools/tool-manager'
 import { ActionMenu } from '../ui/action-menu'
@@ -23,6 +29,7 @@ import { SelectionManager } from './selection-manager'
 useScene.getState().loadScene()
 console.log('Loaded scene in editor')
 initSpatialGridSync()
+initSpaceDetectionSync(useScene, useEditor)
 
 export default function Editor() {
   useKeyboard()
@@ -41,7 +48,7 @@ export default function Editor() {
         {/* Editor only system to toggle zone visibility */}
         <ZoneSystem />
         {/* <Stats /> */}
-        <Grid cellColor="#666" sectionColor="#999" fadeDistance={30} />
+        <Grid cellColor="#aaa" sectionColor="#ccc" fadeDistance={30} />
         <ToolManager />
         <CustomCameraControls />
       </Viewer>
@@ -49,7 +56,6 @@ export default function Editor() {
   )
 }
 
-
 const Grid = ({
   cellSize = 0.5,
   cellThickness = 0.5,

apps/editor/components/ui/action-menu/view-toggles.tsx

@@ -18,11 +18,39 @@ const levelModeLabels: Record<'stacked' | 'exploded' | 'solo', string> = {
 
 const levelModeOrder: ('stacked' | 'exploded' | 'solo')[] = ['stacked', 'exploded', 'solo']
 
+type WallMode = 'up' | 'cutaway' | 'down'
+
+const wallModeConfig: Record<
+  WallMode,
+  { icon: React.FC<React.ComponentProps<'img'>>; label: string }
+> = {
+  up: {
+    icon: (props) => (
+      <img alt="Full Height" height={20} src="/icons/room.png" width={20} {...props} />
+    ),
+    label: 'Full Height',
+  },
+  cutaway: {
+    icon: (props) => (
+      <img alt="Cutaway" height={20} src="/icons/wallcut.png" width={20} {...props} />
+    ),
+    label: 'Cutaway',
+  },
+  down: {
+    icon: (props) => <img alt="Low" height={20} src="/icons/walllow.png" width={20} {...props} />,
+    label: 'Low',
+  },
+}
+
+const wallModeOrder: WallMode[] = ['cutaway', 'up', 'down']
+
 export function ViewToggles() {
   const cameraMode = useViewer((state) => state.cameraMode)
   const setCameraMode = useViewer((state) => state.setCameraMode)
   const levelMode = useViewer((state) => state.levelMode)
   const setLevelMode = useViewer((state) => state.setLevelMode)
+  const wallMode = useViewer((state) => state.wallMode)
+  const setWallMode = useViewer((state) => state.setWallMode)
   const showScans = useViewer((state) => state.showScans)
   const setShowScans = useViewer((state) => state.setShowScans)
   const showGuides = useViewer((state) => state.showGuides)
@@ -43,6 +71,13 @@ export function ViewToggles() {
     if (nextMode) setLevelMode(nextMode)
   }
 
+  const cycleWallMode = () => {
+    const currentIndex = wallModeOrder.indexOf(wallMode)
+    const nextIndex = (currentIndex + 1) % wallModeOrder.length
+    const nextMode = wallModeOrder[nextIndex]
+    if (nextMode) setWallMode(nextMode)
+  }
+
   return (
     <div className="flex items-center gap-1">
       {/* Camera Mode */}
@@ -91,6 +126,31 @@ export function ViewToggles() {
         </TooltipContent>
       </Tooltip>
 
+      {/* Wall Mode */}
+      <Tooltip>
+        <TooltipTrigger asChild>
+          <Button
+            className={cn(
+              'h-8 w-8 text-zinc-400 transition-all p-0',
+              wallMode !== 'cutaway'
+                ? 'bg-emerald-500/20 text-emerald-400'
+                : 'hover:bg-zinc-800',
+            )}
+            onClick={cycleWallMode}
+            size="icon"
+            variant="ghost"
+          >
+            {(() => {
+              const Icon = wallModeConfig[wallMode].icon
+              return <Icon className="h-5 w-5" />
+            })()}
+          </Button>
+        </TooltipTrigger>
+        <TooltipContent>
+          <p>Walls: {wallModeConfig[wallMode].label}</p>
+        </TooltipContent>
+      </Tooltip>
+
       {/* Show Scans */}
       <Tooltip>
         <TooltipTrigger asChild>

apps/editor/store/use-editor.tsx

@@ -1,6 +1,6 @@
 'use client'
 
-import { type BuildingNode, type ItemNode, type LevelNode, useScene } from '@pascal-app/core'
+import { type BuildingNode, type ItemNode, type LevelNode, type Space, useScene } from '@pascal-app/core'
 import { useViewer } from '@pascal-app/viewer'
 import { create } from 'zustand'
 import type { AssetInput } from '@pascal-app/core'
@@ -60,6 +60,9 @@ type EditorState = {
   setMovingNode: (node: ItemNode | null) => void
   selectedReferenceId: string | null
   setSelectedReferenceId: (id: string | null) => void
+  // Space detection for cutaway mode
+  spaces: Record<string, Space>
+  setSpaces: (spaces: Record<string, Space>) => void
 }
 
 const useEditor = create<EditorState>()((set, get) => ({
@@ -174,6 +177,8 @@ const useEditor = create<EditorState>()((set, get) => ({
   setMovingNode: (node) => set({ movingNode: node }),
   selectedReferenceId: null,
   setSelectedReferenceId: (id) => set({ selectedReferenceId: id }),
+  spaces: {},
+  setSpaces: (spaces) => set({ spaces }),
 }))
 
 export default useEditor

packages/core/src/index.ts

@@ -40,3 +40,5 @@ export { WallSystem } from './systems/wall/wall-system'
 export { isObject } from './utils/types'
 // Asset storage
 export { saveAsset, loadAssetUrl } from './lib/asset-storage'
+// Space detection
+export { detectSpacesForLevel, wallTouchesOthers, initSpaceDetectionSync, type Space } from './lib/space-detection'

packages/core/src/lib/space-detection.ts

@@ -0,0 +1,641 @@
+import type { WallNode } from '../schema'
+
+// ============================================================================
+// TYPES
+// ============================================================================
+
+export type Space = {
+  id: string
+  levelId: string
+  polygon: Array<[number, number]>
+  wallIds: string[]
+  isExterior: boolean
+}
+
+// ============================================================================
+// SYNC INITIALIZATION
+// ============================================================================
+
+/**
+ * Initializes space detection sync with scene and editor stores
+ * Call this once during app initialization
+ */
+export function initSpaceDetectionSync(
+  sceneStore: any, // useScene store
+  editorStore: any, // useEditor store
+): () => void {
+  const prevWallsByLevel = new Map<string, Set<string>>()
+  let isProcessing = false // Prevent re-entrant calls
+
+  // Subscribe to scene changes (standard Zustand subscribe, not selector-based)
+  const unsubscribe = sceneStore.subscribe((state: any) => {
+    // Skip if already processing to avoid infinite loops
+    if (isProcessing) return
+
+    const nodes = state.nodes
+    const currentWallsByLevel = new Map<string, Set<string>>()
+
+    // Group walls by level
+    for (const node of Object.values(nodes)) {
+      if ((node as any).type === 'wall' && (node as any).parentId) {
+        const levelId = (node as any).parentId
+        if (!currentWallsByLevel.has(levelId)) {
+          currentWallsByLevel.set(levelId, new Set())
+        }
+        currentWallsByLevel.get(levelId)!.add((node as any).id)
+      }
+    }
+
+    // Check each level for changes
+    const levelsToUpdate = new Set<string>()
+
+    // Check for new walls (created)
+    for (const [levelId, wallIds] of currentWallsByLevel.entries()) {
+      const prevWallIds = prevWallsByLevel.get(levelId)
+
+      if (!prevWallIds) {
+        // New level with walls - run detection if there are multiple walls
+        if (wallIds.size > 1) {
+          levelsToUpdate.add(levelId)
+        }
+        continue
+      }
+
+      // Find newly added walls
+      for (const wallId of wallIds) {
+        if (!prevWallIds.has(wallId)) {
+          // Wall was added - check if it touches other walls
+          const wall = nodes[wallId as keyof typeof nodes] as WallNode
+          const otherWalls = Array.from(wallIds)
+            .filter((id) => id !== wallId)
+            .map((id) => nodes[id as keyof typeof nodes] as WallNode)
+            .filter(Boolean)
+
+          if (wallTouchesOthers(wall, otherWalls)) {
+            levelsToUpdate.add(levelId)
+            break
+          }
+        }
+      }
+    }
+
+    // Check for deleted walls
+    for (const [levelId, prevWallIds] of prevWallsByLevel.entries()) {
+      const currentWallIds = currentWallsByLevel.get(levelId)
+
+      if (!currentWallIds) {
+        // All walls deleted from level - clear spaces
+        if (prevWallIds.size > 0) {
+          levelsToUpdate.add(levelId)
+        }
+        continue
+      }
+
+      // Check if any walls were deleted
+      for (const wallId of prevWallIds) {
+        if (!currentWallIds.has(wallId)) {
+          // Wall was deleted - run detection
+          levelsToUpdate.add(levelId)
+          break
+        }
+      }
+    }
+
+    // Run detection for affected levels
+    if (levelsToUpdate.size > 0) {
+      isProcessing = true
+      try {
+        runSpaceDetection(Array.from(levelsToUpdate), sceneStore, editorStore, nodes)
+      } finally {
+        isProcessing = false
+      }
+    }
+
+    // Update previous walls reference
+    prevWallsByLevel.clear()
+    for (const [levelId, wallIds] of currentWallsByLevel.entries()) {
+      prevWallsByLevel.set(levelId, wallIds)
+    }
+  })
+
+  return unsubscribe
+}
+
+/**
+ * Runs space detection for the given levels
+ * Updates wall nodes and editor spaces
+ */
+function runSpaceDetection(
+  levelIds: string[],
+  sceneStore: any,
+  editorStore: any,
+  nodes: any,
+): void {
+  const { updateNode } = sceneStore.getState()
+  const { setSpaces } = editorStore.getState()
+
+  const allSpaces: Record<string, any> = {}
+
+  for (const levelId of levelIds) {
+    // Get walls for this level
+    const walls = Object.values(nodes).filter(
+      (node: any) => node.type === 'wall' && node.parentId === levelId,
+    ) as WallNode[]
+
+    if (walls.length === 0) {
+      // No walls - clear any spaces for this level
+      continue
+    }
+
+    // Run detection
+    const { wallUpdates, spaces } = detectSpacesForLevel(levelId, walls)
+
+    // Update wall nodes (only if values changed to avoid infinite loop)
+    for (const update of wallUpdates) {
+      const wall = nodes[update.wallId as keyof typeof nodes] as WallNode
+      if (wall.frontSide !== update.frontSide || wall.backSide !== update.backSide) {
+        updateNode(update.wallId as any, {
+          frontSide: update.frontSide,
+          backSide: update.backSide,
+        })
+      }
+    }
+
+    // Store spaces
+    for (const space of spaces) {
+      allSpaces[space.id] = space
+    }
+  }
+
+  // Update editor spaces
+  setSpaces(allSpaces)
+}
+
+type Grid = {
+  cells: Map<string, 'empty' | 'wall' | 'exterior' | 'interior'>
+  resolution: number
+  minX: number
+  minZ: number
+  maxX: number
+  maxZ: number
+  width: number
+  height: number
+}
+
+type WallSideUpdate = {
+  wallId: string
+  frontSide: 'interior' | 'exterior' | 'unknown'
+  backSide: 'interior' | 'exterior' | 'unknown'
+}
+
+// ============================================================================
+// MAIN DETECTION FUNCTION
+// ============================================================================
+
+/**
+ * Detects spaces for a level by flood-filling a grid from the edges
+ * Returns wall side updates and detected spaces
+ */
+export function detectSpacesForLevel(
+  levelId: string,
+  walls: WallNode[],
+  gridResolution: number = 0.5, // Match spatial grid cell size
+): {
+  wallUpdates: WallSideUpdate[]
+  spaces: Space[]
+} {
+  if (walls.length === 0) {
+    return { wallUpdates: [], spaces: [] }
+  }
+
+  // Build grid from walls
+  const grid = buildGrid(walls, gridResolution)
+
+  // Flood fill from edges to mark exterior
+  floodFillFromEdges(grid)
+
+  // Find interior spaces
+  const interiorSpaces = findInteriorSpaces(grid, levelId)
+
+  // Assign wall sides
+  const wallUpdates = assignWallSides(walls, grid)
+
+  return {
+    wallUpdates,
+    spaces: interiorSpaces,
+  }
+}
+
+// ============================================================================
+// GRID BUILDING
+// ============================================================================
+
+/**
+ * Builds a discrete grid and marks cells occupied by walls
+ */
+function buildGrid(walls: WallNode[], resolution: number): Grid {
+  // Find bounds
+  let minX = Number.POSITIVE_INFINITY
+  let minZ = Number.POSITIVE_INFINITY
+  let maxX = Number.NEGATIVE_INFINITY
+  let maxZ = Number.NEGATIVE_INFINITY
+
+  for (const wall of walls) {
+    minX = Math.min(minX, wall.start[0], wall.end[0])
+    minZ = Math.min(minZ, wall.start[1], wall.end[1])
+    maxX = Math.max(maxX, wall.start[0], wall.end[0])
+    maxZ = Math.max(maxZ, wall.start[1], wall.end[1])
+  }
+
+  // Add padding around bounds
+  const padding = 2 // meters
+  minX -= padding
+  minZ -= padding
+  maxX += padding
+  maxZ += padding
+
+  const width = Math.ceil((maxX - minX) / resolution)
+  const height = Math.ceil((maxZ - minZ) / resolution)
+
+  const grid: Grid = {
+    cells: new Map(),
+    resolution,
+    minX,
+    minZ,
+    maxX,
+    maxZ,
+    width,
+    height,
+  }
+
+  // Mark wall cells
+  for (const wall of walls) {
+    markWallCells(grid, wall)
+  }
+
+  return grid
+}
+
+/**
+ * Marks all grid cells occupied by a wall using line rasterization
+ * Uses denser sampling to ensure continuous barriers
+ */
+function markWallCells(grid: Grid, wall: WallNode): void {
+  const thickness = wall.thickness ?? 0.2
+  const halfThickness = thickness / 2
+
+  const [x1, z1] = wall.start
+  const [x2, z2] = wall.end
+
+  // Wall direction vector
+  const dx = x2 - x1
+  const dz = z2 - z1
+  const len = Math.sqrt(dx * dx + dz * dz)
+  if (len < 0.001) return
+
+  // Normalized direction and perpendicular
+  const dirX = dx / len
+  const dirZ = dz / len
+  const perpX = -dirZ
+  const perpZ = dirX
+
+  // Denser sampling along wall length (at least 2x resolution)
+  const steps = Math.max(Math.ceil(len / (grid.resolution * 0.5)), 2)
+  for (let i = 0; i <= steps; i++) {
+    const t = i / steps
+    const x = x1 + dx * t
+    const z = z1 + dz * t
+
+    // Denser sampling across wall thickness
+    const thicknessSteps = Math.max(Math.ceil(thickness / (grid.resolution * 0.5)), 2)
+    for (let j = 0; j <= thicknessSteps; j++) {
+      const offset = (j / thicknessSteps - 0.5) * thickness
+      const wx = x + perpX * offset
+      const wz = z + perpZ * offset
+
+      const key = getCellKey(grid, wx, wz)
+      if (key) {
+        grid.cells.set(key, 'wall')
+      }
+    }
+  }
+}
+
+// ============================================================================
+// FLOOD FILL
+// ============================================================================
+
+/**
+ * Flood fills from all edge cells to mark exterior space
+ */
+function floodFillFromEdges(grid: Grid): void {
+  const queue: string[] = []
+
+  // Add all edge cells to queue
+  for (let x = 0; x < grid.width; x++) {
+    for (let z = 0; z < grid.height; z++) {
+      // Only process edge cells
+      if (x === 0 || x === grid.width - 1 || z === 0 || z === grid.height - 1) {
+        const key = getCellKeyFromIndex(x, z, grid.width)
+        const cell = grid.cells.get(key)
+        if (cell !== 'wall') {
+          grid.cells.set(key, 'exterior')
+          queue.push(key)
+        }
+      }
+    }
+  }
+
+  // Flood fill
+  while (queue.length > 0) {
+    const key = queue.shift()!
+    const [x, z] = parseCellKey(key)
+
+    // Check 4 neighbors
+    const neighbors: [number, number][] = [
+      [x + 1, z],
+      [x - 1, z],
+      [x, z + 1],
+      [x, z - 1],
+    ]
+
+    for (const [nx, nz] of neighbors) {
+      if (nx < 0 || nx >= grid.width || nz < 0 || nz >= grid.height) continue
+
+      const nKey = getCellKeyFromIndex(nx, nz, grid.width)
+      const cell = grid.cells.get(nKey)
+
+      if (cell !== 'wall' && cell !== 'exterior') {
+        grid.cells.set(nKey, 'exterior')
+        queue.push(nKey)
+      }
+    }
+  }
+}
+
+// ============================================================================
+// INTERIOR SPACE DETECTION
+// ============================================================================
+
+/**
+ * Finds all interior spaces (connected regions not marked as exterior or wall)
+ */
+function findInteriorSpaces(grid: Grid, levelId: string): Space[] {
+  const spaces: Space[] = []
+  const visited = new Set<string>()
+
+  // Scan grid for interior cells
+  for (let x = 0; x < grid.width; x++) {
+    for (let z = 0; z < grid.height; z++) {
+      const key = getCellKeyFromIndex(x, z, grid.width)
+      if (visited.has(key)) continue
+
+      const cell = grid.cells.get(key)
+      if (cell === 'wall' || cell === 'exterior') {
+        visited.add(key)
+        continue
+      }
+
+      // Found interior cell - flood fill to find full space
+      const spaceCells = new Set<string>()
+      const queue = [key]
+      visited.add(key)
+      spaceCells.add(key)
+      // Mark the seed cell as interior in the grid
+      grid.cells.set(key, 'interior')
+
+      while (queue.length > 0) {
+        const curKey = queue.shift()!
+        const [cx, cz] = parseCellKey(curKey)
+
+        const neighbors: [number, number][] = [
+          [cx + 1, cz],
+          [cx - 1, cz],
+          [cx, cz + 1],
+          [cx, cz - 1],
+        ]
+
+        for (const [nx, nz] of neighbors) {
+          if (nx < 0 || nx >= grid.width || nz < 0 || nz >= grid.height) continue
+
+          const nKey = getCellKeyFromIndex(nx, nz, grid.width)
+          if (visited.has(nKey)) continue
+
+          const nCell = grid.cells.get(nKey)
+          if (nCell === 'wall' || nCell === 'exterior') {
+            visited.add(nKey)
+            continue
+          }
+
+          visited.add(nKey)
+          spaceCells.add(nKey)
+          // Mark as interior in grid
+          grid.cells.set(nKey, 'interior')
+          queue.push(nKey)
+        }
+      }
+
+      // Create space from cells
+      const polygon = extractPolygonFromCells(spaceCells, grid)
+      spaces.push({
+        id: `space-${spaces.length}`,
+        levelId,
+        polygon,
+        wallIds: [],
+        isExterior: false,
+      })
+    }
+  }
+
+  return spaces
+}
+
+/**
+ * Extracts a simplified polygon from a set of grid cells
+ * Returns bounding box for now (can be improved to trace actual boundary)
+ */
+function extractPolygonFromCells(cells: Set<string>, grid: Grid): Array<[number, number]> {
+  let minX = Number.POSITIVE_INFINITY
+  let minZ = Number.POSITIVE_INFINITY
+  let maxX = Number.NEGATIVE_INFINITY
+  let maxZ = Number.NEGATIVE_INFINITY
+
+  for (const key of cells) {
+    const [x, z] = parseCellKey(key)
+    const worldX = grid.minX + x * grid.resolution
+    const worldZ = grid.minZ + z * grid.resolution
+
+    minX = Math.min(minX, worldX)
+    minZ = Math.min(minZ, worldZ)
+    maxX = Math.max(maxX, worldX)
+    maxZ = Math.max(maxZ, worldZ)
+  }
+
+  // Return bounding box as polygon
+  return [
+    [minX, minZ],
+    [maxX, minZ],
+    [maxX, maxZ],
+    [minX, maxZ],
+  ]
+}
+
+// ============================================================================
+// WALL SIDE ASSIGNMENT
+// ============================================================================
+
+/**
+ * Assigns front/back side classification to each wall based on grid
+ */
+function assignWallSides(walls: WallNode[], grid: Grid): WallSideUpdate[] {
+  const updates: WallSideUpdate[] = []
+
+  for (const wall of walls) {
+    const thickness = wall.thickness ?? 0.2
+    const [x1, z1] = wall.start
+    const [x2, z2] = wall.end
+
+    // Wall direction and perpendicular
+    const dx = x2 - x1
+    const dz = z2 - z1
+    const len = Math.sqrt(dx * dx + dz * dz)
+    if (len < 0.001) continue
+
+    const perpX = -dz / len
+    const perpZ = dx / len
+
+    // Sample point on front side (perpendicular direction)
+    const midX = (x1 + x2) / 2
+    const midZ = (z1 + z2) / 2
+    // Sample beyond wall thickness + one full grid cell to ensure we're in the next cell
+    const offset = thickness / 2 + grid.resolution
+
+    const frontX = midX + perpX * offset
+    const frontZ = midZ + perpZ * offset
+    const backX = midX - perpX * offset
+    const backZ = midZ - perpZ * offset
+
+    // Check what space each side faces
+    const frontKey = getCellKey(grid, frontX, frontZ)
+    const backKey = getCellKey(grid, backX, backZ)
+
+    const frontCell = frontKey ? grid.cells.get(frontKey) : undefined
+    const backCell = backKey ? grid.cells.get(backKey) : undefined
+
+    const frontSide = classifySide(frontCell)
+    const backSide = classifySide(backCell)
+
+    updates.push({
+      wallId: wall.id,
+      frontSide,
+      backSide,
+    })
+  }
+
+  return updates
+}
+
+/**
+ * Classifies a cell as interior, exterior, or unknown
+ */
+function classifySide(cell: string | undefined): 'interior' | 'exterior' | 'unknown' {
+  if (cell === 'exterior') return 'exterior'
+  if (cell === 'interior') return 'interior'
+  // Wall cells or out-of-bounds (undefined) are unknown
+  return 'unknown'
+}
+
+// ============================================================================
+// GRID UTILITIES
+// ============================================================================
+
+/**
+ * Gets grid cell key from world coordinates
+ */
+function getCellKey(grid: Grid, x: number, z: number): string | null {
+  const cellX = Math.floor((x - grid.minX) / grid.resolution)
+  const cellZ = Math.floor((z - grid.minZ) / grid.resolution)
+
+  if (cellX < 0 || cellX >= grid.width || cellZ < 0 || cellZ >= grid.height) {
+    return null
+  }
+
+  return `${cellX},${cellZ}`
+}
+
+/**
+ * Gets cell key from grid indices
+ */
+function getCellKeyFromIndex(x: number, z: number, width: number): string {
+  return `${x},${z}`
+}
+
+/**
+ * Parses cell key back to indices
+ */
+function parseCellKey(key: string): [number, number] {
+  const parts = key.split(',')
+  return [Number.parseInt(parts[0]!, 10), Number.parseInt(parts[1]!, 10)]
+}
+
+// ============================================================================
+// WALL CONNECTIVITY DETECTION
+// ============================================================================
+
+/**
+ * Checks if a wall touches any other walls
+ * Used to determine if space detection should run
+ */
+export function wallTouchesOthers(wall: WallNode, otherWalls: WallNode[]): boolean {
+  const threshold = 0.1 // 10cm connection threshold
+
+  for (const other of otherWalls) {
+    if (other.id === wall.id) continue
+
+    // Check if any endpoint of wall is close to any endpoint or segment of other
+    if (
+      distanceToSegment(wall.start, other.start, other.end) < threshold ||
+      distanceToSegment(wall.end, other.start, other.end) < threshold ||
+      distanceToSegment(other.start, wall.start, wall.end) < threshold ||
+      distanceToSegment(other.end, wall.start, wall.end) < threshold
+    ) {
+      return true
+    }
+  }
+
+  return false
+}
+
+/**
+ * Distance from point to line segment
+ */
+function distanceToSegment(
+  point: [number, number],
+  segStart: [number, number],
+  segEnd: [number, number],
+): number {
+  const [px, pz] = point
+  const [x1, z1] = segStart
+  const [x2, z2] = segEnd
+
+  const dx = x2 - x1
+  const dz = z2 - z1
+  const lenSq = dx * dx + dz * dz
+
+  if (lenSq < 0.0001) {
+    // Segment is a point
+    const dpx = px - x1
+    const dpz = pz - z1
+    return Math.sqrt(dpx * dpx + dpz * dpz)
+  }
+
+  // Project point onto line
+  const t = Math.max(0, Math.min(1, ((px - x1) * dx + (pz - z1) * dz) / lenSq))
+  const projX = x1 + t * dx
+  const projZ = z1 + t * dz
+
+  const distX = px - projX
+  const distZ = pz - projZ
+
+  return Math.sqrt(distX * distX + distZ * distZ)
+}

packages/core/src/schema/nodes/wall.ts

@@ -16,6 +16,9 @@ export const WallNode = BaseNode.extend({
   // e.g., start/end points for path
   start: z.tuple([z.number(), z.number()]),
   end: z.tuple([z.number(), z.number()]),
+  // Space detection for cutaway mode
+  frontSide: z.enum(['interior', 'exterior', 'unknown']).default('unknown'),
+  backSide: z.enum(['interior', 'exterior', 'unknown']).default('unknown'),
 }).describe(
   dedent`
   Wall node - used to represent a wall in the building
@@ -24,6 +27,8 @@ export const WallNode = BaseNode.extend({
   - start: start point of the wall in level coordinate system
   - end: end point of the wall in level coordinate system
   - size: size of the wall in grid units
+  - frontSide: whether the front side faces interior, exterior, or unknown
+  - backSide: whether the back side faces interior, exterior, or unknown
   `,
 )
 export type WallNode = z.infer<typeof WallNode>

packages/core/src/systems/wall/wall-system.tsx

@@ -38,6 +38,7 @@ export const WallSystem = () => {
       const node = nodes[id]
       if (!node || node.type !== 'wall') return
 
+      console.log('wall front/back', node.frontSide, node.backSide)
       const levelId = node.parentId
       if (!levelId) return
 

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

@@ -9,17 +9,17 @@ import { useNodeEvents } from '../../../hooks/use-node-events'
 // Shared materials to avoid creating new instances for every mesh
 const defaultMaterial = new MeshStandardNodeMaterial({
   color: 0xffffff,
-  roughness: 0.8,
+  roughness: 1,
   metalness: 0,
 })
 
 const glassMaterial = new MeshStandardNodeMaterial({
   name: 'glass',
-  color: 'skyblue',
+  color: 'lightgray',
   roughness: 0.8,
   metalness: 0,
   transparent: true,
-  opacity: 0.25,
+  opacity: 0.35,
   side: DoubleSide,
   depthWrite: false,
 })

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

@@ -15,7 +15,6 @@ export const WallRenderer = ({ node }: { node: WallNode }) => {
     <mesh ref={ref} castShadow receiveShadow visible={node.visible}>
       {/* WallSystem will replace this geometry in the next frame */}
       <boxGeometry args={[0, 0, 0]} />
-      <meshStandardMaterial color="white"  />
       <mesh name="collision-mesh" {...handlers} visible={false}>
         <boxGeometry args={[0, 0, 0]} />
       </mesh>

packages/viewer/src/components/viewer/index.tsx

@@ -7,6 +7,7 @@ import * as THREE from 'three/webgpu'
 import { GuideSystem } from '../../systems/guide/guide-system'
 import { LevelSystem } from '../../systems/level/level-system'
 import { ScanSystem } from '../../systems/scan/scan-system'
+import { WallCutout } from '../../systems/wall/wall-cutout'
 import { SceneRenderer } from '../renderers/scene-renderer'
 import { Lights } from './lights'
 import PostProcessing from './post-processing'
@@ -27,12 +28,12 @@ interface ViewerProps {
 const Viewer: React.FC<ViewerProps> = ({ children, selectionManager = 'default' }) => {
   return (
     <Canvas
-      className={'bg-[#303035]'}
+      className={'bg-[#fafafa]'}
       gl={async (props) => {
         const renderer = new THREE.WebGPURenderer(props as any)
         await renderer.init()
         renderer.toneMapping = THREE.ACESFilmicToneMapping
-        renderer.toneMappingExposure = 1.2
+        renderer.toneMappingExposure = 0.9
         return renderer
       }}
       shadows={{
@@ -41,7 +42,7 @@ const Viewer: React.FC<ViewerProps> = ({ children, selectionManager = 'default'
       }}
       camera={{ position: [50, 50, 50], fov: 50 }}
     >
-      <color attach="background" args={['#ececec']} />
+      <color attach="background" args={['#fafafa']} />
       <ViewerCamera />
 
       {/* <directionalLight position={[10, 10, 5]} intensity={0.5} castShadow
@@ -55,6 +56,7 @@ const Viewer: React.FC<ViewerProps> = ({ children, selectionManager = 'default'
       <LevelSystem />
       <GuideSystem />
       <ScanSystem />
+      <WallCutout />
       {/* Core systems */}
       <CeilingSystem />
       <ItemSystem />

packages/viewer/src/components/viewer/lights.tsx

@@ -1,4 +1,3 @@
-import { Environment } from '@react-three/drei'
 import { useRef } from 'react'
 import type { DirectionalLight, OrthographicCamera } from 'three/webgpu'
 
@@ -16,11 +15,12 @@ export function Lights() {
         ref={lightRef}
         position={[10, 10, 10]}
         castShadow
-      intensity={1}
+        intensity={4}
         shadow-bias={-0.002}
         shadow-normalBias={0.3}
         shadow-mapSize={[1024, 1024]}
         shadow-radius={3}
+        shadow-intensity={0.4}
       >
         <orthographicCamera
           ref={shadowCamera}
@@ -34,8 +34,19 @@ export function Lights() {
         />
       </directionalLight>
 
-          <ambientLight intensity={0.2} />
-          <Environment preset="sunset" environmentIntensity={0.4} />
+      <directionalLight
+        position={[-10, 10, -10]}
+        intensity={0.75}
+      />
+
+      <directionalLight
+        position={[-10, 10, 10]}
+        intensity={1}
+      />
+
+      <ambientLight intensity={0.5} 
+        color='white' />
+      {/* <Environment preset="sunset" environmentIntensity={0.4} /> */}
     </>
   )
 }

packages/viewer/src/components/viewer/post-processing.tsx

@@ -1,99 +1,186 @@
-import { useFrame, useThree } from "@react-three/fiber";
-import { useEffect, useRef } from "react";
-import { Color } from "three";
-import { outline } from "three/addons/tsl/display/OutlineNode.js";
-import { oscSine, pass, time, uniform } from "three/tsl";
-import { PostProcessing, type WebGPURenderer } from "three/webgpu";
-import useViewer from "../../store/use-viewer";
+import { useFrame, useThree } from '@react-three/fiber'
+import { useEffect, useRef } from 'react'
+import { Color, UnsignedByteType } from 'three'
+import { outline } from 'three/addons/tsl/display/OutlineNode.js'
+import { ssgi } from 'three/addons/tsl/display/SSGINode.js'
+import { traa } from 'three/addons/tsl/display/TRAANode.js'
+import {
+  add,
+  colorToDirection,
+  diffuseColor,
+  directionToColor,
+  mrt,
+  normalView,
+  oscSine,
+  output,
+  pass,
+  sample,
+  time,
+  uniform,
+  vec4,
+  velocity,
+} from 'three/tsl'
+import { PostProcessing, type WebGPURenderer } from 'three/webgpu'
+import useViewer from '../../store/use-viewer'
+
+// SSGI Parameters - adjust these to fine-tune global illumination and ambient occlusion
+export const SSGI_PARAMS = {
+  enabled: true,
+  sliceCount: 2,
+  stepCount: 8,
+  radius: 2,
+  expFactor: 2,
+  thickness: 0.5,
+  backfaceLighting: 0.5,
+  aoIntensity: 1.5,
+  giIntensity: 0.5,
+  useLinearThickness: false,
+  useScreenSpaceSampling: true,
+  useTemporalFiltering: true,
+}
 
 const PostProcessingPasses = () => {
-  const { gl: renderer, scene, camera } = useThree();
-  const postProcessingRef = useRef<PostProcessing | null>(null);
+  const { gl: renderer, scene, camera } = useThree()
+  const postProcessingRef = useRef<PostProcessing | null>(null)
 
   useEffect(() => {
     if (!renderer || !scene || !camera) {
-      return;
+      return
     }
 
-    const scenePass = pass(scene, camera);
+    // Scene pass with MRT for SSGI
+    const scenePass = pass(scene, camera)
+    scenePass.setMRT(
+      mrt({
+        output: output,
+        diffuseColor: diffuseColor,
+        normal: directionToColor(normalView),
+        velocity: velocity,
+      }),
+    )
+
+    // Get texture outputs
+    const scenePassColor = scenePass.getTextureNode('output')
+    const scenePassDiffuse = scenePass.getTextureNode('diffuseColor')
+    const scenePassDepth = scenePass.getTextureNode('depth')
+    const scenePassNormal = scenePass.getTextureNode('normal')
+    const scenePassVelocity = scenePass.getTextureNode('velocity')
+
+    // Optimize texture bandwidth
+    const diffuseTexture = scenePass.getTexture('diffuseColor')
+    diffuseTexture.type = UnsignedByteType
+
+    const normalTexture = scenePass.getTexture('normal')
+    normalTexture.type = UnsignedByteType
+
+    // Extract normal from color-encoded texture
+    const sceneNormal = sample((uv) => {
+      return colorToDirection(scenePassNormal.sample(uv))
+    })
+
+    // SSGI Pass (cast to PerspectiveCamera for SSGI)
+    const giPass = ssgi(scenePassColor, scenePassDepth, sceneNormal, camera as any)
+    giPass.sliceCount.value = SSGI_PARAMS.sliceCount
+    giPass.stepCount.value = SSGI_PARAMS.stepCount
+    giPass.radius.value = SSGI_PARAMS.radius
+    giPass.expFactor.value = SSGI_PARAMS.expFactor
+    giPass.thickness.value = SSGI_PARAMS.thickness
+    giPass.backfaceLighting.value = SSGI_PARAMS.backfaceLighting
+    giPass.aoIntensity.value = SSGI_PARAMS.aoIntensity
+    giPass.giIntensity.value = SSGI_PARAMS.giIntensity
+    giPass.useLinearThickness.value = SSGI_PARAMS.useLinearThickness
+    giPass.useScreenSpaceSampling.value = SSGI_PARAMS.useScreenSpaceSampling
+    giPass.useTemporalFiltering = SSGI_PARAMS.useTemporalFiltering
+
+    // Extract GI and AO from SSGI pass
+    const gi = giPass.rgb
+    const ao = giPass.a
+
+    // Composite: scene * AO + diffuse * GI
+    const compositePass = vec4(
+      add(scenePassColor.rgb.mul(ao), scenePassDiffuse.rgb.mul(gi)),
+      scenePassColor.a,
+    )
+
+    // TRAA (Temporal Reprojection Anti-Aliasing)
+    const traaPass = traa(compositePass, scenePassDepth, scenePassVelocity, camera)
 
     function generateSelectedOutlinePass() {
-      const edgeStrength = uniform(3);
-      const edgeGlow = uniform(0);
-      const edgeThickness = uniform(1);
-      const visibleEdgeColor = uniform(new Color(0xffffff));
-      const hiddenEdgeColor = uniform(new Color(0xf3ff47));
+      const edgeStrength = uniform(3)
+      const edgeGlow = uniform(0)
+      const edgeThickness = uniform(1)
+      const visibleEdgeColor = uniform(new Color(0xffffff))
+      const hiddenEdgeColor = uniform(new Color(0xf3ff47))
 
       const outlinePass = outline(scene, camera, {
         selectedObjects: useViewer.getState().outliner.selectedObjects,
         edgeGlow,
         edgeThickness,
-      });
-      const { visibleEdge, hiddenEdge } = outlinePass;
+      })
+      const { visibleEdge, hiddenEdge } = outlinePass
 
       const outlineColor = visibleEdge
         .mul(visibleEdgeColor)
         .add(hiddenEdge.mul(hiddenEdgeColor))
-        .mul(edgeStrength);
+        .mul(edgeStrength)
 
-      return outlineColor;
+      return outlineColor
     }
     function generateHoverOutlinePass() {
-      const edgeStrength = uniform(5);
-      const edgeGlow = uniform(0.5);
-      const edgeThickness = uniform(1.5);
-      const pulsePeriod = uniform(3);
-      const visibleEdgeColor = uniform(new Color(0x00aaff));
-      const hiddenEdgeColor = uniform(new Color(0xf3ff47));
+      const edgeStrength = uniform(5)
+      const edgeGlow = uniform(0.5)
+      const edgeThickness = uniform(1.5)
+      const pulsePeriod = uniform(3)
+      const visibleEdgeColor = uniform(new Color(0x00aaff))
+      const hiddenEdgeColor = uniform(new Color(0xf3ff47))
 
       const outlinePass = outline(scene, camera, {
         selectedObjects: useViewer.getState().outliner.hoveredObjects,
         edgeGlow,
         edgeThickness,
-      });
-      const { visibleEdge, hiddenEdge } = outlinePass;
+      })
+      const { visibleEdge, hiddenEdge } = outlinePass
 
-      const period = time.div(pulsePeriod).mul(2);
-      const osc = oscSine(period).mul(0.5).add(0.5); // osc [ 0.5, 1.0 ]
+      const period = time.div(pulsePeriod).mul(2)
+      const osc = oscSine(period).mul(0.5).add(0.5) // osc [ 0.5, 1.0 ]
 
       const outlineColor = visibleEdge
         .mul(visibleEdgeColor)
         .add(hiddenEdge.mul(hiddenEdgeColor))
-        .mul(edgeStrength);
-      const outlinePulse = pulsePeriod
-        .greaterThan(0)
-        .select(outlineColor.mul(osc), outlineColor);
-      return outlinePulse;
+        .mul(edgeStrength)
+      const outlinePulse = pulsePeriod.greaterThan(0).select(outlineColor.mul(osc), outlineColor)
+      return outlinePulse
     }
 
     // Setup post-processing
-    const postProcessing = new PostProcessing(
-      renderer as unknown as WebGPURenderer,
-    );
+    const postProcessing = new PostProcessing(renderer as unknown as WebGPURenderer)
 
-    const selectedOutlinePass = generateSelectedOutlinePass();
-    const hoverOutlinePass = generateHoverOutlinePass();
+    const selectedOutlinePass = generateSelectedOutlinePass()
+    const hoverOutlinePass = generateHoverOutlinePass()
 
-    postProcessing.outputNode = selectedOutlinePass
-      .add(hoverOutlinePass)
-      .add(scenePass);
-    postProcessingRef.current = postProcessing;
+    // Combine SSGI output with outlines
+    const finalOutput = SSGI_PARAMS.enabled
+      ? selectedOutlinePass.add(hoverOutlinePass).add(traaPass)
+      : selectedOutlinePass.add(hoverOutlinePass).add(scenePassColor)
+
+    postProcessing.outputNode = finalOutput
+    postProcessingRef.current = postProcessing
 
     return () => {
       if (postProcessingRef.current) {
-        postProcessingRef.current.dispose();
+        postProcessingRef.current.dispose()
       }
-      postProcessingRef.current = null;
-    };
-  }, [renderer, scene, camera]);
+      postProcessingRef.current = null
+    }
+  }, [renderer, scene, camera])
 
   useFrame(() => {
     if (postProcessingRef.current) {
-      postProcessingRef.current.render();
+      postProcessingRef.current.render()
     }
-  }, 1);
+  }, 1)
 
-  return null;
-};
+  return null
+}
 
-export default PostProcessingPasses;
+export default PostProcessingPasses

packages/viewer/src/store/use-viewer.ts

@@ -24,32 +24,35 @@ type Outliner = {
 };
 
 type ViewerState = {
-  selection: SelectionPath;
-  hoveredId: AnyNode["id"] | ZoneNode["id"] | null;
-  setHoveredId: (id: AnyNode["id"] | ZoneNode["id"] | null) => void;
+  selection: SelectionPath
+  hoveredId: AnyNode['id'] | ZoneNode['id'] | null
+  setHoveredId: (id: AnyNode['id'] | ZoneNode['id'] | null) => void
 
-  cameraMode: "perspective" | "orthographic";
-  setCameraMode: (mode: "perspective" | "orthographic") => void;
+  cameraMode: 'perspective' | 'orthographic'
+  setCameraMode: (mode: 'perspective' | 'orthographic') => void
 
-  levelMode: "stacked" | "exploded" | "solo" | "manual";
-  setLevelMode: (mode: "stacked" | "exploded" | "solo" | "manual") => void;
+  levelMode: 'stacked' | 'exploded' | 'solo' | 'manual'
+  setLevelMode: (mode: 'stacked' | 'exploded' | 'solo' | 'manual') => void
 
-  showScans: boolean;
-  setShowScans: (show: boolean) => void;
+  wallMode: 'up' | 'cutaway' | 'down'
+  setWallMode: (mode: 'up' | 'cutaway' | 'down') => void
 
-  showGuides: boolean;
-  setShowGuides: (show: boolean) => void;
+  showScans: boolean
+  setShowScans: (show: boolean) => void
+
+  showGuides: boolean
+  setShowGuides: (show: boolean) => void
 
   // Smart selection update
-  setSelection: (updates: Partial<SelectionPath>) => void;
-  resetSelection: () => void;
+  setSelection: (updates: Partial<SelectionPath>) => void
+  resetSelection: () => void
 
-  outliner: Outliner; // No setter as we will manipulate directly the arrays
+  outliner: Outliner // No setter as we will manipulate directly the arrays
 
   // Export functionality
-  exportScene: (() => Promise<void>) | null;
-  setExportScene: (fn: (() => Promise<void>) | null) => void;
-};
+  exportScene: (() => Promise<void>) | null
+  setExportScene: (fn: (() => Promise<void>) | null) => void
+}
 
 const useViewer = create<ViewerState>()((set, get) => ({
   selection: { buildingId: null, levelId: null, zoneId: null, selectedIds: [] },
@@ -62,6 +65,9 @@ const useViewer = create<ViewerState>()((set, get) => ({
   levelMode: "stacked",
   setLevelMode: (mode) => set({ levelMode: mode }),
 
+  wallMode: 'cutaway',
+  setWallMode: (mode) => set({ wallMode: mode }),
+
   showScans: true,
   setShowScans: (show) => set({ showScans: show }),
 

packages/viewer/src/systems/wall/wall-cutout.tsx

@@ -0,0 +1,115 @@
+import { sceneRegistry, useScene, type WallNode } from '@pascal-app/core'
+import { useFrame } from '@react-three/fiber'
+import { useRef } from 'react'
+import { Fn, float, fract, length, mix, positionLocal, smoothstep, step, vec2 } from 'three/tsl'
+
+import { type Mesh, MeshStandardNodeMaterial, Vector3 } from 'three/webgpu'
+import useViewer from '../../store/use-viewer'
+
+const tmpVec = new Vector3()
+const u = new Vector3()
+const v = new Vector3()
+
+// Dot pattern shader
+const dotPattern = Fn(() => {
+  // Create a repeating grid pattern based on world position
+  const scale = float(0.1) // Dot grid spacing (10cm)
+  const dotSize = float(0.3) // Size of dots relative to grid
+
+  // Use XY coordinates for pattern on wall face
+  const uv = vec2(positionLocal.x, positionLocal.y).div(scale)
+  const gridUV = fract(uv)
+
+  // Distance from center of grid cell (creates circular dots)
+  const dist = length(gridUV.sub(0.5))
+
+  // Create dots: 1 where we want dots, 0 elsewhere
+  const dots = step(dist, dotSize.mul(0.5))
+
+  // Vertical fade: fade out as Y increases (from bottom to top)
+  const fadeHeight = float(2.5) // Fade over 2.5 meters
+  const yFade = float(1).sub(smoothstep(float(0), fadeHeight, positionLocal.y))
+
+  return dots.mul(yFade)
+})
+
+const invsibleWallMaterial = new MeshStandardNodeMaterial({
+  transparent: true,
+  opacityNode: mix(float(0.0), float(0.24), dotPattern()),
+  color: 'white',
+  depthWrite: false,
+  emissive: 'white',
+})
+const wallMaterial = new MeshStandardNodeMaterial({
+  color: 'white',
+  roughness: 1,
+  metalness: 0,
+})
+
+export const WallCutout = () => {
+  const lastCameraPosition = useRef(new Vector3())
+  const lastCameraTarget = useRef(new Vector3())
+  const lastUpdateTime = useRef(0)
+  const lastWallMode = useRef<string>(useViewer.getState().wallMode)
+  const lastNumberOfWalls = useRef(0)
+
+  useFrame(({ camera, clock }) => {
+    const wallMode = useViewer.getState().wallMode
+    const currentTime = clock.elapsedTime
+    const currentCameraPosition = camera.position
+    camera.getWorldDirection(tmpVec)
+    tmpVec.add(currentCameraPosition)
+
+    // Throttle: only update if camera moved significantly AND enough time passed
+    const distanceMoved = currentCameraPosition.distanceTo(lastCameraPosition.current)
+    const directionChanged = tmpVec.distanceTo(lastCameraTarget.current)
+    const timeSinceUpdate = currentTime - lastUpdateTime.current
+
+    // Update if moved > 0.5m OR direction changed > 0.3 AND at least 100ms passed
+    if (
+      ((distanceMoved > 0.5 || directionChanged > 0.3) && timeSinceUpdate > 0.1) ||
+      lastWallMode.current !== wallMode ||
+      sceneRegistry.byType.wall.size !== lastNumberOfWalls.current
+    ) {
+      // Camera has moved, update cutout logic here
+
+      // Update last known positions and time
+      lastCameraPosition.current.copy(currentCameraPosition)
+      lastCameraTarget.current.copy(tmpVec)
+      lastUpdateTime.current = currentTime
+      camera.getWorldDirection(u)
+
+      const walls = sceneRegistry.byType.wall
+      walls.forEach((wallId) => {
+        const wallMesh = sceneRegistry.nodes.get(wallId)
+        if (!wallMesh) return
+        const wallNode = useScene.getState().nodes[wallId as WallNode['id']]
+        if (!wallNode || wallNode.type !== 'wall') return
+        let hideWall = wallNode.frontSide === 'interior' && wallNode.backSide === 'interior'
+
+        if (wallMode === 'up') {
+          hideWall = false
+        } else if (wallMode === 'down') {
+          hideWall = true
+        } else {
+          wallMesh.getWorldDirection(v) 
+          if (v.dot(u) < 0) {
+            // Front side
+            if (wallNode.frontSide === 'exterior' && wallNode.backSide !== 'exterior') {
+              hideWall = true
+            }
+          } else {
+            // Back side
+            if (wallNode.backSide === 'exterior' && wallNode.frontSide !== 'exterior') {
+              hideWall = true
+            }
+          }
+        }
+        ;(wallMesh as Mesh).material = hideWall ? invsibleWallMaterial : wallMaterial
+      })
+      lastWallMode.current = wallMode
+      lastNumberOfWalls.current = sceneRegistry.byType.wall.size
+    }
+  })
+  return null
+}