[vtkusers] VTK class to do interpolation of scalar values

[David Gobbi]

On Mon, Dec 7, 2009 at 9:51 AM, David Doria <daviddoria+vtk at gmail.com> wrote:
> On Mon, Dec 7, 2009 at 11:43 AM, Jin Ryong Kim <jinryongkim at gmail.com> wrote:
>> I have a question about interpolation method in VTK.
>> Currently, I'm trying to interpolate scalar values between data points to
>> create a contour map.
>> I have some data points set (x, y, z) and scalar values related with each
>> data point.
>> So far, I found out vtkProbeFilter but when I tried, nothing came up.
>> My questions are as follow.
>> 1. Is vtkProbeFilter the right choice in this case?
>> 2. If not, what are the right vtk classes to accomplish such a goal?
>> If anyone has the solution for this, please let me know.
>> Thanks in advance!
>
> Jin,
>
> If I'm not mistaken you sent this same question yesterday. I am
> interesting in making an example of this so I have started poking
> around. I understand that you may be in a hurry, but asking twice is
> just going to annoy people on the list, making your answer come
> slower, not faster.
>
> Can anyone confirm or deny that ProbeFilter is the right way to go?

The probe needs cells to interpolate the data.  If all you have is
points, then you have to apply delaunay first to make the cells, and
then use probe to interpolate the data onto a grid (i.e. make an
image), and then contour the grid.  It might also be possible to
contour directly from the output of delaunay, but I'm not sure whether
VTK can do that.  I'm no expert in this area, but hopefully I've
answered your question.

   David