[Paraview] Fail to get the mapper of a volume actor!

Hi All, I used the codes following to get the mapper of a volume actor, but I get NULL while *volume *is not NULL. * vtkAbstractMapper3D *mapper = NULL; if ( (volume = vtkVolume::SafeDownCast(propCandidate)) != NULL ) mapper = volume-GetMapper(); * Why? Thanks for any advice! Best

[Paraview] Fail to get the mapper of a volume actor

Hi All, I used the codes following to get the mapper of a volume actor, but I get NULL while *volume *is not NULL. * vtkAbstractMapper3D *mapper = NULL; if ( (volume = vtkVolume::SafeDownCast(propCandidate)) != NULL ) mapper = volume-GetMapper(); * Why? Thanks for any advice! Best