fix ply and stl exports (#1141)

* fix ply and stl exports

* A snapshot a day keeps the bugs away! 📷🐛 (OS: ubuntu)

* trigger ci

* explanation comment

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

src/components/ExportButton.tsx

@@ -75,7 +75,11 @@ export const ExportButton = ({ children, className }: ExportButtonProps) => {
           },
         }
       }
-      if (values.type === 'obj' || values.type === 'stl') {
+      if (
+        values.type === 'obj' ||
+        values.type === 'stl' ||
+        values.type === 'ply'
+      ) {
         values.units = baseUnit
       }
       if (
@@ -86,6 +90,9 @@ export const ExportButton = ({ children, className }: ExportButtonProps) => {
         // Set the storage type.
         values.storage = storage
       }
+      if (values.type === 'ply' || values.type === 'stl') {
+        values.selection = { type: 'default_scene' }
+      }
       engineCommandManager.sendSceneCommand({
         type: 'modeling_cmd_req',
         cmd: {
@@ -177,13 +184,13 @@ export const ExportButton = ({ children, className }: ExportButtonProps) => {
                       <option value="standard">standard</option>
                     </>
                   )}
-                  {type === 'ply' && (
+                  {type === 'stl' && (
                     <>
                       <option value="ascii">ascii</option>
                       <option value="binary">binary</option>
                     </>
                   )}
-                  {type === 'stl' && (
+                  {type === 'ply' && (
                     <>
                       <option value="ascii">ascii</option>
                       <option value="binary_little_endian">