Implemented interactive rendering support

Author: mtortora

polykit/renderers/backends.py

@@ -33,11 +33,14 @@ def interactive(self, standalone=True):
         """
 
         view = interact.SceneView(self.scene)
-        view.show()
-            
+
         if standalone:
+            view.show()
             interact.app.exec_()
 
+        else:
+            return view
+            
 
     def static(self,
                pathtrace=True,