diff --git a/apps/editor/app/api/presets/[id]/thumbnail/route.ts b/apps/editor/app/api/presets/[id]/thumbnail/route.ts
new file mode 100644
index 00000000..377c883b
--- /dev/null
+++ b/apps/editor/app/api/presets/[id]/thumbnail/route.ts
@@ -0,0 +1,59 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { headers } from 'next/headers'
+import { auth } from '@/lib/auth'
+import { supabaseAdmin } from '@/lib/supabase/server'
+
+// POST /api/presets/[id]/thumbnail
+// Accepts a raw PNG blob, uploads to preset-thumbnails bucket, updates thumbnail_url
+export async function POST(
+  req: NextRequest,
+  { params }: { params: Promise<{ id: string }> },
+) {
+  const session = await auth.api.getSession({ headers: await headers() })
+  if (!session?.user) {
+    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+  }
+
+  const { id } = await params
+
+  const { data: existing } = await supabaseAdmin
+    .from('presets')
+    .select('user_id')
+    .eq('id', id)
+    .single()
+
+  if (!existing || existing.user_id !== session.user.id) {
+    return NextResponse.json({ error: 'Not found or forbidden' }, { status: 403 })
+  }
+
+  const blob = await req.blob()
+
+  const filename = `${id}/thumbnail.png`
+  const { data: uploadData, error: uploadError } = await supabaseAdmin.storage
+    .from('preset-thumbnails')
+    .upload(filename, blob, {
+      contentType: 'image/png',
+      upsert: true,
+    })
+
+  if (uploadError) {
+    return NextResponse.json({ error: uploadError.message }, { status: 500 })
+  }
+
+  const { data: urlData } = supabaseAdmin.storage
+    .from('preset-thumbnails')
+    .getPublicUrl(uploadData.path)
+
+  const thumbnailUrl = `${urlData.publicUrl}?t=${Date.now()}`
+
+  const { error: updateError } = await supabaseAdmin
+    .from('presets')
+    .update({ thumbnail_url: thumbnailUrl })
+    .eq('id', id)
+
+  if (updateError) {
+    return NextResponse.json({ error: updateError.message }, { status: 500 })
+  }
+
+  return NextResponse.json({ thumbnail_url: thumbnailUrl })
+}
diff --git a/apps/editor/components/editor/index.tsx b/apps/editor/components/editor/index.tsx
index ec095031..0fe78eee 100644
--- a/apps/editor/components/editor/index.tsx
+++ b/apps/editor/components/editor/index.tsx
@@ -25,6 +25,7 @@ import { FloatingActionMenu } from './floating-action-menu'
 import { Grid } from './grid'
 import { SelectionManager } from './selection-manager'
 import { SiteEdgeLabels } from './site-edge-labels'
+import { PresetThumbnailGenerator } from './preset-thumbnail-generator'
 import { ThumbnailGenerator } from './thumbnail-generator'
 
 
@@ -120,6 +121,7 @@ export default function Editor({ projectId }: EditorProps) {
         <ToolManager />
         <CustomCameraControls />
         <ThumbnailGenerator projectId={projectId} />
+        <PresetThumbnailGenerator />
         <SiteEdgeLabels />
       </Viewer>
     </div>
diff --git a/apps/editor/components/editor/preset-thumbnail-generator.tsx b/apps/editor/components/editor/preset-thumbnail-generator.tsx
new file mode 100644
index 00000000..b55a1f3a
--- /dev/null
+++ b/apps/editor/components/editor/preset-thumbnail-generator.tsx
@@ -0,0 +1,120 @@
+'use client'
+
+import { emitter, sceneRegistry } from '@pascal-app/core'
+import { useThree } from '@react-three/fiber'
+import { useCallback, useEffect } from 'react'
+import * as THREE from 'three'
+
+const THUMBNAIL_SIZE = 1080
+const CAMERA_FOV = 45
+
+export const PresetThumbnailGenerator = () => {
+  const gl = useThree((state) => state.gl)
+  const scene = useThree((state) => state.scene)
+
+  const generate = useCallback(
+    async ({ presetId, nodeId }: { presetId: string; nodeId: string }) => {
+      const target = sceneRegistry.nodes.get(nodeId)
+      if (!target) {
+        console.error('❌ PresetThumbnail: node not found', nodeId)
+        return
+      }
+
+      // Compute each mesh's transform relative to the target node (cancels world
+      // position/rotation), so the item is always rendered at origin with a known
+      // neutral orientation regardless of where it's placed in the scene.
+      target.updateWorldMatrix(true, true)
+      const targetInverse = new THREE.Matrix4().copy(target.matrixWorld).invert()
+      const relMatrix = new THREE.Matrix4()
+
+      const clones: THREE.Object3D[] = []
+      target.traverse((obj) => {
+        if (!(obj instanceof THREE.Mesh || obj instanceof THREE.Line || obj instanceof THREE.Points)) return
+        const c = obj.clone(false) // shallow clone: copies geometry, material, visible — no children
+        relMatrix.multiplyMatrices(targetInverse, obj.matrixWorld)
+        relMatrix.decompose(c.position, c.quaternion, c.scale)
+        scene.add(c)
+        clones.push(c)
+      })
+
+      if (clones.length === 0) {
+        console.error('❌ PresetThumbnail: no renderable objects found', nodeId)
+        return
+      }
+
+      // Combined bounding box across all clones
+      const box = new THREE.Box3()
+      for (const c of clones) box.expandByObject(c)
+
+      if (box.isEmpty()) {
+        for (const c of clones) scene.remove(c)
+        console.error('❌ PresetThumbnail: empty bounding box', nodeId)
+        return
+      }
+
+      const sphere = new THREE.Sphere()
+      box.getBoundingSphere(sphere)
+
+      // Camera: aspect matches canvas (center-cropped to square after render)
+      const { width, height } = gl.domElement
+      const camera = new THREE.PerspectiveCamera(CAMERA_FOV, width / height, 0.01, 1000)
+      const dir = new THREE.Vector3(-0.5, 0.5, 0.5).normalize()
+      const fovRad = (CAMERA_FOV * Math.PI) / 180
+      const dist = (sphere.radius / Math.tan(fovRad / 2)) * 1.3
+      camera.position.copy(sphere.center).addScaledVector(dir, dist)
+      camera.lookAt(sphere.center)
+      camera.updateProjectionMatrix()
+
+      // Hide all scene geometry except the clones — leave lights, cameras, etc. intact
+      const cloneSet = new Set<THREE.Object3D>(clones)
+      const snapshot = new Map<THREE.Object3D, boolean>()
+      scene.traverse((obj) => {
+        if (cloneSet.has(obj)) return
+        if (!(obj instanceof THREE.Mesh || obj instanceof THREE.Line || obj instanceof THREE.Points)) return
+        snapshot.set(obj, obj.visible)
+        obj.visible = false
+      })
+
+      gl.render(scene, camera)
+
+      // Restore visibility and remove clones
+      snapshot.forEach((wasVisible, obj) => {
+        obj.visible = wasVisible
+      })
+      for (const c of clones) scene.remove(c)
+
+      // Center-crop to square and scale to THUMBNAIL_SIZE
+      const minDim = Math.min(width, height)
+      const sx = Math.round((width - minDim) / 2)
+      const sy = Math.round((height - minDim) / 2)
+      const offscreen = document.createElement('canvas')
+      offscreen.width = THUMBNAIL_SIZE
+      offscreen.height = THUMBNAIL_SIZE
+      const ctx = offscreen.getContext('2d')!
+      ctx.drawImage(gl.domElement, sx, sy, minDim, minDim, 0, 0, THUMBNAIL_SIZE, THUMBNAIL_SIZE)
+
+      offscreen.toBlob(async (blob) => {
+        if (!blob) {
+          console.error('❌ PresetThumbnail: failed to create blob')
+          return
+        }
+        const res = await fetch(`/api/presets/${presetId}/thumbnail`, {
+          method: 'POST',
+          body: blob,
+          headers: { 'Content-Type': 'image/png' },
+        })
+        if (!res.ok) {
+          console.error('❌ PresetThumbnail: upload failed', await res.text())
+        }
+      }, 'image/png')
+    },
+    [gl, scene],
+  )
+
+  useEffect(() => {
+    emitter.on('preset:generate-thumbnail', generate)
+    return () => emitter.off('preset:generate-thumbnail', generate)
+  }, [generate])
+
+  return null
+}
diff --git a/apps/editor/components/ui/panels/door-panel.tsx b/apps/editor/components/ui/panels/door-panel.tsx
index ed9f1f40..45ef66ce 100644
--- a/apps/editor/components/ui/panels/door-panel.tsx
+++ b/apps/editor/components/ui/panels/door-panel.tsx
@@ -1,6 +1,6 @@
 'use client'
 
-import { type AnyNode, type AnyNodeId, DoorNode, useScene } from '@pascal-app/core'
+import { type AnyNode, type AnyNodeId, DoorNode, emitter, useScene } from '@pascal-app/core'
 import { useViewer } from '@pascal-app/viewer'
 import { BookMarked, Copy, FlipHorizontal2, Move, Trash2 } from 'lucide-react'
 import { useCallback } from 'react'
@@ -141,23 +141,29 @@ export function DoorPanel() {
 
   const handleSavePreset = useCallback(async (name: string) => {
     const data = getDoorPresetData()
-    if (!data) return
-    await fetch('/api/presets', {
+    if (!data || !selectedId) return
+    const res = await fetch('/api/presets', {
       method: 'POST',
       headers: { 'Content-Type': 'application/json' },
       body: JSON.stringify({ type: 'door', name, data }),
     })
-  }, [getDoorPresetData])
+    if (res.ok) {
+      const json = await res.json()
+      const presetId = json.preset?.id
+      if (presetId) emitter.emit('preset:generate-thumbnail', { presetId, nodeId: selectedId })
+    }
+  }, [getDoorPresetData, selectedId])
 
   const handleOverwritePreset = useCallback(async (id: string) => {
     const data = getDoorPresetData()
-    if (!data) return
-    await fetch(`/api/presets/${id}`, {
+    if (!data || !selectedId) return
+    const res = await fetch(`/api/presets/${id}`, {
       method: 'PUT',
       headers: { 'Content-Type': 'application/json' },
       body: JSON.stringify({ data }),
     })
-  }, [getDoorPresetData])
+    if (res.ok) emitter.emit('preset:generate-thumbnail', { presetId: id, nodeId: selectedId })
+  }, [getDoorPresetData, selectedId])
 
   const handleApplyPreset = useCallback((data: Record<string, unknown>) => {
     handleUpdate(data as Partial<DoorNode>)
diff --git a/apps/editor/components/ui/panels/window-panel.tsx b/apps/editor/components/ui/panels/window-panel.tsx
index e4238aac..ed1b55b1 100644
--- a/apps/editor/components/ui/panels/window-panel.tsx
+++ b/apps/editor/components/ui/panels/window-panel.tsx
@@ -1,6 +1,6 @@
 'use client'
 
-import { type AnyNode, type AnyNodeId, WindowNode, useScene } from '@pascal-app/core'
+import { type AnyNode, type AnyNodeId, WindowNode, emitter, useScene } from '@pascal-app/core'
 import { useViewer } from '@pascal-app/viewer'
 import { BookMarked, Copy, FlipHorizontal2, Move, Trash2 } from 'lucide-react'
 import { useCallback } from 'react'
@@ -111,23 +111,29 @@ export function WindowPanel() {
 
   const handleSavePreset = useCallback(async (name: string) => {
     const data = getWindowPresetData()
-    if (!data) return
-    await fetch('/api/presets', {
+    if (!data || !selectedId) return
+    const res = await fetch('/api/presets', {
       method: 'POST',
       headers: { 'Content-Type': 'application/json' },
       body: JSON.stringify({ type: 'window', name, data }),
     })
-  }, [getWindowPresetData])
+    if (res.ok) {
+      const json = await res.json()
+      const presetId = json.preset?.id
+      if (presetId) emitter.emit('preset:generate-thumbnail', { presetId, nodeId: selectedId })
+    }
+  }, [getWindowPresetData, selectedId])
 
   const handleOverwritePreset = useCallback(async (id: string) => {
     const data = getWindowPresetData()
-    if (!data) return
-    await fetch(`/api/presets/${id}`, {
+    if (!data || !selectedId) return
+    const res = await fetch(`/api/presets/${id}`, {
       method: 'PUT',
       headers: { 'Content-Type': 'application/json' },
       body: JSON.stringify({ data }),
     })
-  }, [getWindowPresetData])
+    if (res.ok) emitter.emit('preset:generate-thumbnail', { presetId: id, nodeId: selectedId })
+  }, [getWindowPresetData, selectedId])
 
   const handleApplyPreset = useCallback((data: Record<string, unknown>) => {
     handleUpdate(data as Partial<WindowNode>)
diff --git a/packages/core/src/events/bus.ts b/packages/core/src/events/bus.ts
index 61250974..8e9b9539 100644
--- a/packages/core/src/events/bus.ts
+++ b/packages/core/src/events/bus.ts
@@ -73,6 +73,10 @@ type ToolEvents = {
   'tool:cancel': undefined
 }
 
+type PresetEvents = {
+  'preset:generate-thumbnail': { presetId: string; nodeId: string }
+}
+
 type EditorEvents = GridEvents &
   NodeEvents<'wall', WallEvent> &
   NodeEvents<'item', ItemEvent> &
@@ -86,6 +90,7 @@ type EditorEvents = GridEvents &
   NodeEvents<'window', WindowEvent> &
   NodeEvents<'door', DoorEvent> &
   CameraControlEvents &
-  ToolEvents
+  ToolEvents &
+  PresetEvents
 
 export const emitter = mitt<EditorEvents>()