[Paraview] Automatic color application (AddArray vs SetScalars)

[David Doria]

If I add colors to a polydata using
polydata->GetPointData()->SetScalars ( Colors );

then open the polydata in Paraview, the colors are applied automatically.

However, if I use
polydata->GetPointData()->AddArray ( Colors );

which is apparently (from the vtk-users list) the "new/correct" way to
do this in VTK, I have to go to "display" and change "Color by:" to
"Colors" and then uncheck "Map scalars". Is there a reason that colors
added in this way are not applied automatically?

Thanks,

David