Feat/3d dropdown (#8765)

## Summary
Add mesh_upload and upload_subfolder to combo input schema so
WidgetSelect detects mesh uploads generically instead of hardcoding node
type checks. Inject these flags in load3dLazy.ts so they are available
before THREE.js loads.

Also unify SUPPORTED_EXTENSIONS_ACCEPT across load3d and dropdown, pass
uploadSubfolder prop through to WidgetSelectDropdown for correct upload
path, and update error message to list all supported extensions.

replacement for https://github.com/Comfy-Org/ComfyUI_frontend/pull/7975

(We should include thumbnail but not yet, will do it later)

## Screenshots (if applicable)


https://github.com/user-attachments/assets/2cb4b1da-af4f-439b-9786-3ac780c2480d

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8765-Feat-3d-dropdown-3036d73d365081d8a10ee19d3ed7d295)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Kelly Yang <124ykl@gmail.com>

src/renderer/extensions/vueNodes/widgets/components/WidgetSelect.test.ts

@@ -334,6 +334,24 @@ describe('WidgetSelect Value Binding', () => {
       expect(dropdown.props('allowUpload')).toBe(false)
     })
 
+    it('uses dropdown variant for mesh uploads via spec', () => {
+      const spec: ComboInputSpec = {
+        type: 'COMBO',
+        name: 'model_file',
+        mesh_upload: true,
+        upload_subfolder: '3d'
+      }
+      const widget = createMockWidget('model.glb', {}, undefined, spec)
+      const wrapper = mountComponent(widget, 'model.glb')
+      const dropdown = wrapper.findComponent(WidgetSelectDropdown)
+
+      expect(dropdown.exists()).toBe(true)
+      expect(dropdown.props('assetKind')).toBe('mesh')
+      expect(dropdown.props('allowUpload')).toBe(true)
+      expect(dropdown.props('uploadFolder')).toBe('input')
+      expect(dropdown.props('uploadSubfolder')).toBe('3d')
+    })
+
     it('keeps default select when no spec or media hints are present', () => {
       const widget = createMockWidget('plain', {
         values: ['plain', 'text']

src/renderer/extensions/vueNodes/widgets/components/WidgetSelect.vue

@@ -7,6 +7,7 @@
     :asset-kind="assetKind"
     :allow-upload="allowUpload"
     :upload-folder="uploadFolder"
+    :upload-subfolder="uploadSubfolder"
     :is-asset-mode="isAssetMode"
     :default-layout-mode="defaultLayoutMode"
   />
@@ -58,13 +59,15 @@ const specDescriptor = computed<{
   kind: AssetKind
   allowUpload: boolean
   folder: ResultItemType | undefined
+  subfolder: string | undefined
 }>(() => {
   const spec = comboSpec.value
   if (!spec) {
     return {
       kind: 'unknown',
       allowUpload: false,
-      folder: undefined
+      folder: undefined,
+      subfolder: undefined
     }
   }
 
@@ -73,7 +76,9 @@ const specDescriptor = computed<{
     animated_image_upload,
     video_upload,
     image_folder,
-    audio_upload
+    audio_upload,
+    mesh_upload,
+    upload_subfolder
   } = spec
 
   let kind: AssetKind = 'unknown'
@@ -83,18 +88,26 @@ const specDescriptor = computed<{
     kind = 'image'
   } else if (audio_upload) {
     kind = 'audio'
+  } else if (mesh_upload) {
+    kind = 'mesh'
   }
+
   // TODO: add support for models (checkpoints, VAE, LoRAs, etc.) -- get widgetType from spec
 
   const allowUpload =
     image_upload === true ||
     animated_image_upload === true ||
     video_upload === true ||
-    audio_upload === true
+    audio_upload === true ||
+    mesh_upload === true
+
+  const folder = mesh_upload ? 'input' : image_folder
+
   return {
     kind,
     allowUpload,
-    folder: image_folder
+    folder,
+    subfolder: upload_subfolder
   }
 })
 
@@ -120,6 +133,7 @@ const allowUpload = computed(() => specDescriptor.value.allowUpload)
 const uploadFolder = computed<ResultItemType>(() => {
   return specDescriptor.value.folder ?? 'input'
 })
+const uploadSubfolder = computed(() => specDescriptor.value.subfolder)
 const defaultLayoutMode = computed<LayoutMode>(() => {
   return isAssetMode.value ? 'list' : 'grid'
 })

src/renderer/extensions/vueNodes/widgets/components/WidgetSelectDropdown.vue

@@ -4,6 +4,7 @@ import { computed, provide, ref, toRef, watch } from 'vue'
 import { useI18n } from 'vue-i18n'
 
 import { useTransformCompatOverlayProps } from '@/composables/useTransformCompatOverlayProps'
+import { SUPPORTED_EXTENSIONS_ACCEPT } from '@/extensions/core/load3d/constants'
 import { useAssetFilterOptions } from '@/platform/assets/composables/useAssetFilterOptions'
 import {
   filterItemByBaseModels,
@@ -44,6 +45,7 @@ interface Props {
   assetKind?: AssetKind
   allowUpload?: boolean
   uploadFolder?: ResultItemType
+  uploadSubfolder?: string
   isAssetMode?: boolean
   defaultLayoutMode?: LayoutMode
 }
@@ -143,7 +145,7 @@ const inputItems = computed<FormDropdownItem[]>(() => {
   }))
 })
 const outputItems = computed<FormDropdownItem[]>(() => {
-  if (!['image', 'video'].includes(props.assetKind ?? '')) return []
+  if (!['image', 'video', 'mesh'].includes(props.assetKind ?? '')) return []
 
   const outputs = new Set<string>()
 
@@ -152,7 +154,8 @@ const outputItems = computed<FormDropdownItem[]>(() => {
     task.flatOutputs.forEach((output) => {
       const isTargetType =
         (props.assetKind === 'image' && output.mediaType === 'images') ||
-        (props.assetKind === 'video' && output.mediaType === 'video')
+        (props.assetKind === 'video' && output.mediaType === 'video') ||
+        (props.assetKind === 'mesh' && output.is3D)
 
       if (output.type === 'output' && isTargetType) {
         const path = output.subfolder
@@ -292,6 +295,8 @@ const mediaPlaceholder = computed(() => {
       return t('widgets.uploadSelect.placeholderVideo')
     case 'audio':
       return t('widgets.uploadSelect.placeholderAudio')
+    case 'mesh':
+      return t('widgets.uploadSelect.placeholderMesh')
     case 'model':
       return t('widgets.uploadSelect.placeholderModel')
     case 'unknown':
@@ -316,6 +321,8 @@ const acceptTypes = computed(() => {
       return 'video/*'
     case 'audio':
       return 'audio/*'
+    case 'mesh':
+      return SUPPORTED_EXTENSIONS_ACCEPT
     default:
       return undefined // model or unknown
   }
@@ -365,6 +372,8 @@ const uploadFile = async (
   const body = new FormData()
   body.append('image', file)
   if (isPasted) body.append('subfolder', 'pasted')
+  else if (props.uploadSubfolder)
+    body.append('subfolder', props.uploadSubfolder)
   if (formFields.type) body.append('type', formFields.type)
 
   const resp = await api.fetchApi('/upload/image', {