fix(export): unbreak bakes and STL/OBJ exports on malformed/placeholder meshes (#466)

- roof-system: replace BoxGeometry placeholders (initial swap + empty-roof
  merged shell) with a group-less degenerate geometry — a Box's 6 groups
  against the roof's 4-material array crashed GLTFExporter on every scene
  with a segment-less roof node (prod: 'reading isShaderMaterial'), and
  count-0 groups crash MeshBVH's packed-tree build.
- glb-export: sanitizeMaterialGroups pass repairs any mesh whose geometry
  groups don't line up with its material array before GLTFExporter runs.
- export-manager: give neutralised (attribute-less) meshes an empty position
  attribute before STL/OBJ export — both exporters read position.count
  unconditionally.
- bake-exporter: log the full error stack so the bake worker's console relay
  captures it in the job's error trail.
- viewer: host-controlled disablePostFx prop (Viewer → PostProcessing) that
  skips building the SSGI/denoise pipeline entirely; the ?disable=postFx URL
  flag previously only bypassed it per-frame while still allocating it.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

packages/editor/src/components/editor/bake-exporter.tsx

@@ -41,6 +41,10 @@ export function BakeExporter({
         const buffer = await exportSceneToGlb(sceneGroup, useScene.getState().nodes)
         onComplete(buffer)
       } catch (err) {
+        // The bake worker relays page console output into the job's error
+        // trail; the message alone rarely localises an exporter crash, so
+        // surface the full stack here.
+        console.error('[bake-exporter]', err instanceof Error ? (err.stack ?? err.message) : err)
         onError(err instanceof Error ? err.message : String(err))
       } finally {
         useViewer.getState().setExporting(false)

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

@@ -4,10 +4,33 @@ import { emitter, useScene } from '@pascal-app/core'
 import { useViewer } from '@pascal-app/viewer'
 import { useThree } from '@react-three/fiber'
 import { useEffect } from 'react'
+import * as THREE from 'three'
 import { OBJExporter } from 'three/examples/jsm/exporters/OBJExporter.js'
 import { STLExporter } from 'three/examples/jsm/exporters/STLExporter.js'
 import { exportSceneToGlb, prepareSceneForExport } from '../../lib/glb-export'
 
+// prepareSceneForExport neutralises container meshes (door/window hitbox roots,
+// material-less renderables) with an attribute-less geometry — GLTFExporter
+// emits those as plain transform nodes, but STL/OBJExporter read
+// `position.count` unconditionally and crash. Swap in a geometry with an empty
+// (count-0) position so they iterate zero vertices instead. Shared: the export
+// scene is a throwaway clone, only its geometry *ref* is swapped.
+const EMPTY_POSITION_GEOMETRY = new THREE.BufferGeometry()
+EMPTY_POSITION_GEOMETRY.setAttribute(
+  'position',
+  new THREE.Float32BufferAttribute(new Float32Array(0), 3),
+)
+
+function ensurePositionAttributes(root: THREE.Object3D) {
+  root.traverse((object) => {
+    const renderable = object as THREE.Mesh & { isLine?: boolean; isPoints?: boolean }
+    if (!(renderable.isMesh || renderable.isLine || renderable.isPoints)) return
+    if (!renderable.geometry?.getAttribute('position')) {
+      renderable.geometry = EMPTY_POSITION_GEOMETRY
+    }
+  })
+}
+
 export function ExportManager() {
   const scene = useThree((state) => state.scene)
   const setExportScene = useViewer((state) => state.setExportScene)
@@ -41,7 +64,8 @@ export function ExportManager() {
       } finally {
         emitter.emit('thumbnail:after-capture', undefined)
       }
-      const { scene: exportScene, animations } = prepared
+      const { scene: exportScene } = prepared
+      ensurePositionAttributes(exportScene)
 
       if (format === 'stl') {
         const exporter = new STLExporter()

packages/editor/src/lib/glb-export.ts

@@ -130,6 +130,7 @@ export function prepareSceneForExport(
   }
 
   pruneNonRenderableMeshes(scene, identityNodes)
+  sanitizeMaterialGroups(scene, identityNodes)
   convertMaterials(scene)
 
   const { clips, clipNamesByNode } = bakeAnimationClips(cloneByOriginal, nodes)
@@ -229,6 +230,68 @@ function pruneNonRenderableMeshes(root: THREE.Object3D, identityNodes: Set<THREE
   }
 }
 
+/**
+ * Repair meshes whose geometry groups don't line up with their material array —
+ * GLTFExporter reads `materials[group.materialIndex]` per group and crashes on
+ * undefined (`reading 'isShaderMaterial'`). The known producer is a roof
+ * placeholder (BoxGeometry's 6 groups vs the 4 roof materials), but any
+ * system/CSG output can end up here, so repair generically:
+ *  - groups indexing past the array (or drawing zero triangles) are dropped;
+ *  - null slots referenced by surviving groups get the hidden placeholder;
+ *  - a mesh left with no drawable group — including an array-material mesh
+ *    with no groups at all (three draws nothing for those, e.g. the roof
+ *    system's degenerate placeholder) — is neutralised like other
+ *    non-renderables (kept as a bare transform node, or removed if a leaf
+ *    that carries no node identity).
+ * Geometry/material refs are shared with the live scene (`clone(true)` is
+ * shallow for both), so repairs swap refs instead of mutating in place.
+ */
+function sanitizeMaterialGroups(root: THREE.Object3D, identityNodes: Set<THREE.Object3D>) {
+  const toRemove: THREE.Object3D[] = []
+  root.traverse((object) => {
+    const mesh = object as THREE.Mesh
+    if (!mesh.isMesh || !Array.isArray(mesh.material)) return
+    const materials = mesh.material
+    const groups = mesh.geometry.groups
+    const broken =
+      groups.length === 0 ||
+      groups.some((g) => (g.materialIndex ?? 0) >= materials.length || g.count === 0) ||
+      materials.some((m) => m == null)
+    if (!broken) return
+
+    const validGroups = groups.filter(
+      (g) => (g.materialIndex ?? 0) < materials.length && g.count !== 0,
+    )
+    if (validGroups.length === 0) {
+      if (mesh.children.length > 0 || identityNodes.has(mesh)) {
+        mesh.geometry = EMPTY_GEOMETRY
+        mesh.material = PLACEHOLDER_MATERIAL
+      } else {
+        toRemove.push(mesh)
+      }
+      return
+    }
+    // Only the group list needs repair — share the attribute/index refs
+    // instead of geometry.clone(), which deep-copies every vertex buffer.
+    if (validGroups.length !== groups.length) {
+      const geometry = new THREE.BufferGeometry()
+      geometry.index = mesh.geometry.index
+      for (const [name, attribute] of Object.entries(mesh.geometry.attributes)) {
+        geometry.setAttribute(name, attribute)
+      }
+      geometry.morphAttributes = mesh.geometry.morphAttributes
+      geometry.morphTargetsRelative = mesh.geometry.morphTargetsRelative
+      geometry.setDrawRange(mesh.geometry.drawRange.start, mesh.geometry.drawRange.count)
+      geometry.groups = validGroups.map((g) => ({ ...g }))
+      mesh.geometry = geometry
+    }
+    mesh.material = materials.map((m) => m ?? PLACEHOLDER_MATERIAL)
+  })
+  for (const object of toRemove) {
+    object.removeFromParent()
+  }
+}
+
 function isRenderableMesh(mesh: THREE.Mesh): boolean {
   const position = mesh.geometry?.getAttribute('position')
   if (!position || position.count === 0) return false