solid test and disable importing nonsolid objects

.gitignore

@@ -103,4 +103,8 @@ ENV/
 # blender backup files
 *.blend1
 install_plugin_cad.sh
-.vscode
+.vscode
+
+# emacs backup files
+~*
+*#

cg/blender/import_fcstd/importer.py

@@ -23,6 +23,7 @@ import bpy
 from bpy_extras.node_shader_utils import PrincipledBSDFWrapper
 from import_fcstd.handler import FreeCAD_xml_handler
 from import_fcstd.materials import set_fem_mat
+from import_fcstd.is_object_solid import is_object_solid
 
 logger = logging.getLogger(__name__)
 logging.basicConfig(level=logging.INFO)
@@ -123,6 +124,10 @@ def importer(filename,
                         # TODO add parent visibility check
                         continue
 
+        if not is_object_solid(obj):
+            logger.debug('%s is not solid', obj.Label)
+            continue
+
         verts = []
         edges = []
         faces = []

cg/blender/import_fcstd/is_object_solid.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+# Original code by (C) 2019 yorikvanhavre <yorik@uncreated.net>
+# Copyright (C) 2023 Ilia Kurochkin <brothermechanic@gmail.com>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+import FreeCAD
+
+
+def is_object_solid(obj):
+    """If obj is solid return True"""
+    if not isinstance(obj, FreeCAD.DocumentObject):
+        return False
+
+    if not hasattr(obj, 'Shape'):
+        return False
+
+    if not hasattr(obj.Shape, 'Solids'):
+        return False
+
+    if len(obj.Shape.Solids) == 0:
+        return False
+
+    return True