[vtkusers] find interpolated scalar at arbitrary point in unstructured volume

[George Zagaris]

Internally, a point-locator is used to minimize the search space of
the algorithm, i.e., the number of cells to be checked by the query.
The point-locator is only build once so subsequent queries are executed
faster.

The core of the algorithm is based on the Newton-Raphson iteration and
the Lagrange shape functions defined over the element using the parametric
center as an initial guess.

Hope this helps.

Regards,
George

On Sun, Apr 10, 2011 at 8:22 PM, Liam Kurmos <quantum.leaf at gmail.com> wrote:
>> VTK does provide functionality for what you describe.
>> You can can call FindCell on your unstructured dataset
>> with your point query and it will return the cell Id that
>> contains the point as well as the interpolation and parametric
>> coordinates w.r.t. the donor cell.
>
> awesome, thanks George.
>
> btw, do you know roughly what of method is used to find the cell?
>
> This functionality is also wrapped
>> by the vtkProbeFilter.
>
> great to know about, it could be very useful sometime.
>
> best regards,
>
> Liam
>
>
>>
>> Best Regards,
>> George
>>
>>
>>> ------------------------------
>>>
>>> Message: 6
>>> Date: Sun, 10 Apr 2011 15:47:04 +0100
>>> From: Liam Kurmos <quantum.leaf at gmail.com>
>>> Subject: [vtkusers] find interpolated scalar at arbitrary point in
>>>        unstructured volume
>>> To: vtk <vtkusers at vtk.org>
>>> Message-ID: <BANLkTimQRf_Nv7jOCK+pWcup3YfprakvJQ at mail.gmail.com>
>>> Content-Type: text/plain; charset=ISO-8859-1
>>>
>>> i have a vtkunstructuredgrid volume dataset with a scalar field
>>> defined at each point in the point data. What methods should i use to
>>> find the interpolated value at an arbitrary point in the volume?
>>> if this is not provided in vtk is there a way to find which cell a
>>> particular value is in?
>>>
>>> Liam
>>>
>>>
>>> ------------------------------
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>