Merge pull request godotengine#309 from Ben1138/fix_node_tree_crash

Fix crash for potential non existent texture images.

io_scene_godot/converters/material/script_shader/node_tree.py

@@ -429,7 +429,10 @@ def export_texture(escn_file, export_settings, image):
  else:
  src_path = image.filepath_raw
  if os.path.normpath(src_path) != os.path.normpath(dst_path):
- copyfile(src_path, dst_path)
+ if not os.path.exists(src_path):
+ logging.warning("Texture Image '%s' does not exist!", src_path)
+ else:
+ copyfile(src_path, dst_path)
 
  img_resource = ExternalResource(dst_path, "Texture")
  return escn_file.add_external_resource(img_resource, image)