fusion: purge meshes/ folder prima di ogni export

Aggiunto _purge_meshes_dir() chiamato all inizio di export_meshes_and_hierarchy. Cancella .obj/.stl/.mtl residui di export precedenti (component rinominati o rimossi dal modello Fusion) che altrimenti rimanevano come orfani nella cartella di output e venivano potenzialmente caricati dal viewer come nodi vuoti. Conteggio in stats.purged_stale, mostrato nel messageBox finale di entrambi gli script (plotter + ATL).

ExportKinematicGraph.py

@@ -1558,10 +1558,40 @@ def _export_component_mesh(export_mgr, component, filepath_noext):
     return (None, None)
 
 
+def _purge_meshes_dir(meshes_dir):
+    """Rimuove tutti i file di mesh residui in `meshes_dir`.
+
+    Tiene la cartella ma cancella .obj / .stl / .mtl. Cosi' i residui di
+    export precedenti (component rinominati o rimossi dal modello Fusion)
+    non rimangono come "orfani" nella cartella di output.
+
+    Ritorna il numero di file cancellati. Cartella inesistente -> 0.
+    """
+    if not os.path.isdir(meshes_dir):
+        return 0
+    removed = 0
+    try:
+        for fname in os.listdir(meshes_dir):
+            low = fname.lower()
+            if not (low.endswith('.obj') or low.endswith('.stl') or low.endswith('.mtl')):
+                continue
+            try:
+                os.remove(os.path.join(meshes_dir, fname))
+                removed += 1
+            except Exception:
+                continue
+    except Exception:
+        pass
+    return removed
+
+
 def export_meshes_and_hierarchy(design, root_comp, out_dir):
     """Esporta le mesh dei component (deduplicato) + costruisce la gerarchia.
 
     Workflow:
+        * Pulisce eventuali file mesh residui in `out_dir/meshes/` (orfani
+          di export precedenti, es. component rinominati o rimossi dal
+          modello Fusion).
         * Scorre tutte le occurrences visibili (lightBulbOn + non suppressed).
         * Per ogni occurrence, se il suo Component contiene bodies e non e'
           ancora stato esportato, esporta `meshes/<safe>.obj` (o .stl in
@@ -1574,13 +1604,19 @@ def export_meshes_and_hierarchy(design, root_comp, out_dir):
     """
     meshes_dir = os.path.join(out_dir, 'meshes')
     os.makedirs(meshes_dir, exist_ok=True)
+    purged = _purge_meshes_dir(meshes_dir)
 
     em = design.exportManager
     nodes = []
     # comp.id -> path relativo del meshFile gia' esportato (per dedup).
     component_to_meshfile = {}
     used_filenames = set()
-    stats = {'exported_meshes': 0, 'failed_meshes': 0, 'skipped_invisible': 0}
+    stats = {
+        'exported_meshes':   0,
+        'failed_meshes':     0,
+        'skipped_invisible': 0,
+        'purged_stale':      purged,
+    }
 
     def _maybe_export_component_mesh(comp):
         """Esporta la mesh del component se non gia' fatto. Ritorna path o None."""
@@ -1862,16 +1898,18 @@ def run(context):
                 'Nodi gerarchia: {1}\n'
                 'Mesh esportate: {2}\n'
                 'Mesh fallite: {3}\n'
-                'Occurrences invisibili/suppresse: {4}\n'
-                'Occurrences escluse da filtro nome: {5}\n\n'
-                'Joints: {6}\n'
-                'As-Built Joints: {7}\n'
-                'Motion Links: {8}\n'
-                'Rigid Groups: {9}'.format(
+                'Mesh stale rimosse: {4}\n'
+                'Occurrences invisibili/suppresse: {5}\n'
+                'Occurrences escluse da filtro nome: {6}\n\n'
+                'Joints: {7}\n'
+                'As-Built Joints: {8}\n'
+                'Motion Links: {9}\n'
+                'Rigid Groups: {10}'.format(
                     out_dir,
                     len(nodes),
                     mesh_stats['exported_meshes'],
                     mesh_stats['failed_meshes'],
+                    mesh_stats.get('purged_stale', 0),
                     mesh_stats['skipped_invisible'],
                     mesh_stats.get('skipped_excluded', 0),
                     len(joints_payload['joints']),

ExportKinematicGraph_ATL.py

@@ -562,10 +562,10 @@ def run(context):
             design, root_comp, out_dir
         )
         _annotate_hierarchy(nodes)
+        _log('purged stale meshes: {0}'.format(mesh_stats.get('purged_stale', 0)))
         _log('hierarchy nodes: {0}, mesh ok: {1}, mesh fail: {2}'.format(
             len(nodes), mesh_stats['exported_meshes'], mesh_stats['failed_meshes']
         ))
-
         hierarchy_payload = {
             'metadata': {
                 'documentName': doc_name,
@@ -651,16 +651,17 @@ def run(context):
                 'Export ATL completato.\n\n'
                 'Cartella: {0}\n\n'
                 'Nodi gerarchia: {1}\n'
-                'Mesh esportate: {2} (fallite: {3})\n\n'
-                'Joints: {4} (rinominati {5}, orfani {6})\n'
-                'As-Built Joints: {7} (rinominati {8}, origin recuperati {9}, revolute senza origin {10})\n'
-                'Motion Links: {11}\n'
-                'Rigid Groups: {12}\n\n'
+                'Mesh esportate: {2} (fallite: {3}, stale rimosse: {4})\n\n'
+                'Joints: {5} (rinominati {6}, orfani {7})\n'
+                'As-Built Joints: {8} (rinominati {9}, origin recuperati {10}, revolute senza origin {11})\n'
+                'Motion Links: {12}\n'
+                'Rigid Groups: {13}\n\n'
                 'Log dettagliato: export_atl.log'.format(
                     out_dir,
                     len(nodes),
                     mesh_stats['exported_meshes'],
                     mesh_stats['failed_meshes'],
+                    mesh_stats.get('purged_stale', 0),
                     len(joints_list), joints_renamed, orphans_joints,
                     len(as_built_list), ab_renamed, origin_recovered, revolutes_no_origin,
                     len(motion_links),