Pick events are emitted from cameras rendering offscreen

My code renders a scene with shadow mapping, using object picking. Sometimes, the location of the intersection suddenly jumps far away from where the mouse is, and it turns out that is the intersection if the scene was viewed from the camera rendering the shadowmap. Removing the shadow map rendering portion of the framegraph eliminates the problem.

There should be a way to tell Qt3D which parts of the framegraph are not to be used for picking. Perhaps it could be done by creating a "QNoPicking" subclass of QFramegraphNode that will block traversal when trying to gather cameras for picking, or by adding a property to the QCameraSelector class to indicate the camera should not be used for picking.