Use focal point as the center of rotation (#1948)

* Use focal point as the center of rotation (in jupyter and related contexts)

* Update cq directive too

Author: adam-urbanczyk

cadquery/cq_directive.py

@@ -54,6 +54,7 @@
     roll: vtk.Interaction.Manipulators.vtkMouseCameraTrackballRollManipulator.newInstance(),
 };
 
+manips.rot.setUseFocalPointAsCenterOfRotation(true);
 manips.zoom1.setControl(true);
 manips.zoom2.setButton(3);
 manips.roll.setShift(true);

cadquery/occ_impl/jupyter_tools.py

@@ -92,6 +92,7 @@
         roll: vtk.Interaction.Manipulators.vtkMouseCameraTrackballRollManipulator.newInstance(),
     }};
 
+    manips.rot.setUseFocalPointAsCenterOfRotation(true);
     manips.zoom1.setControl(true);
     manips.zoom2.setScrollEnabled(true);
     manips.roll.setShift(true);