Fix errorous warning about scene not found

utils_bpy/render_settings_setter.py

@@ -29,14 +29,15 @@ def __init__(self, scene: str = None, view_layers: List[str] = None) -> None:
 
   def set_scene(self, scene_name: str) -> None:
     """Set the scene to be rendered."""
-    if scene_name not in bpy.data.scenes.keys():
-      print_utils.print_warning(f"Scene {scene_name} not found!")
-    else:
-      bpy.context.window.scene = bpy.data.scenes[scene_name]
-    if not scene_name and len(bpy.data.scenes) > 1:
-      print_utils.print_warning(
-          "There are more than one scenes, but you didn't tell me which scene to render! So I am"
-          " rendering the last used scene.")
+    if scene_name:
+      if scene_name not in bpy.data.scenes.keys():
+        print_utils.print_warning(f"Scene {scene_name} not found!")
+      else:
+        bpy.context.window.scene = bpy.data.scenes[scene_name]
+      if not scene_name and len(bpy.data.scenes) > 1:
+        print_utils.print_warning(
+            "There are more than one scenes, but you didn't tell me which scene to render! So I am"
+            " rendering the last used scene.")
     self.current_scene_data = bpy.context.scene
     self.current_scene_render = self.current_scene_data.render