Only save models on the active build plate in 3MFWriter

CURA-4792

plugins/3MFWriter/ThreeMFWriter.py

@@ -6,8 +6,9 @@ from UM.Math.Vector import Vector
 from UM.Logger import Logger
 from UM.Math.Matrix import Matrix
 from UM.Application import Application
-import UM.Scene.SceneNode
-from cura.Scene.CuraSceneNode import CuraSceneNode
+from UM.Scene.SceneNode import SceneNode
+
+from cura.CuraApplication import CuraApplication
 
 import Savitar
 
@@ -62,11 +63,15 @@ class ThreeMFWriter(MeshWriter):
         self._store_archive = store_archive
 
     ##  Convenience function that converts an Uranium SceneNode object to a SavitarSceneNode
-    #   \returns Uranium Scenen node.
+    #   \returns Uranium Scene node.
     def _convertUMNodeToSavitarNode(self, um_node, transformation = Matrix()):
-        if type(um_node) not in [UM.Scene.SceneNode.SceneNode, CuraSceneNode]:
+        if not isinstance(um_node, SceneNode):
             return None
 
+        active_build_plate_nr = CuraApplication.getInstance().getBuildPlateModel().activeBuildPlate
+        if um_node.callDecoration("getBuildPlateNumber") != active_build_plate_nr:
+            return
+
         savitar_node = Savitar.SceneNode()
 
         node_matrix = um_node.getLocalTransformation()
@@ -97,6 +102,9 @@ class ThreeMFWriter(MeshWriter):
                 savitar_node.setSetting(key, str(stack.getProperty(key, "value")))
 
         for child_node in um_node.getChildren():
+            # only save the nodes on the active build plate
+            if child_node.callDecoration("getBuildPlateNumber") != active_build_plate_nr:
+                continue
             savitar_child_node = self._convertUMNodeToSavitarNode(child_node)
             if savitar_child_node is not None:
                 savitar_node.addChild(savitar_child_node)