[vtkusers] VTK class to do interpolation of scalar values

[David Doria]

On Mon, Dec 7, 2009 at 12:20 PM, David Gobbi <david.gobbi at gmail.com> wrote:
> 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
>

>From Bill's suggestion I have tried to make an example:
http://www.vtk.org/Wiki/VTK_Examples_Interpolation

the problem is that the Shepard filter outputs an ImageData and the
ContourFilter seems to expect a DataObject.

Jin, this is a simple version of what you are trying to do, correct?
If so, let try to get this little demo working.

Thanks,

David