[vtk-developers] Possible bug in vtkDataSetMapper?

[Berk Geveci]

No problem. The reason for this behavior is that the pipeline does not
look at the modification time of the data objects when computing
pipeline modification time. Therefore, modifying a data object has no
effect. The only exception to this is when a data object without a
producer is assigned as an input to an algorithm. In that case, the
data object's mtime is taken into account. There is also an API (I
can't remember the names of the methods) in the mapper (and many
algorithms) that allow you to use an array other than scalars. So, if
all you want is to color by an array, you don't need to use the
vtkAssignAttribute filter. For an example, grep for ColorBy in
VTK/Graphics/Testing/Tcl. Algorithms have the SetInputArrayToProcess()
method.

-berk


On 9/2/07, Prabhu Ramachandran <prabhu_r at users.sf.net> wrote:
> >>>>> "Berk" == Berk Geveci <berk.geveci at kitware.com> writes:
>
>     Berk> This is not a bug. You are not supposed to be modifying data
>     Berk> objects internal to a pipeline. If you do, you shouldn't
>     Berk> expect the pipeline to update. You can insert a
>     Berk> vtkAssignAttribute filter in the pipeline to do this.
>
> Many thanks for this clarification!  Sorry for the noise.  I am amazed
> that I have not noticed the use of vtkAssignAttribute earlier.
>
> Thanks again and sorry for the false alarm.
>
> regards,
> Prabhu
>