Little hack for htg supercursors
Super cursors in htg fail when reaching a neighbor outside extent. This commit adds a new invalid id in vtkHyperTreeGrid which is use to notify this case. This might need to be done better later
Super cursors in htg fail when reaching a neighbor outside extent. This commit adds a new invalid id in vtkHyperTreeGrid which is use to notify this case. This might need to be done better later