[vtkusers] destroying hedgehog actor

[Danny Holstein]

All;

A general question;  I've created actors for my geometry and have superimposed a hedgehog field representation on top of it, I'm pretty happy the results.  The question is, how do I destroy the old hedgehog actor when I select a different time step?  The old one is still displayed in spite of this code:

  if (sgrid != NULL) {
    sgridActor->Delete();
    hedgehog->Delete();
    sgrid->Delete();
  }
  sgrid = vtkStructuredGrid::New();
  sgridActor = vtkActor::New();


   ...Dan