[vtkusers] slice structured grid with polydata

[Cory Quammen]

That's great, Justin. Thanks for reporting back.

Cory

On Mon, Mar 7, 2016 at 4:04 PM, Justin Weber <onlyjus at gmail.com> wrote:

> Cory,
>
> Thanks for your help. I got it working! I might put the code up as an
> example.
>
>
> Justin
>
> On Thu, Feb 18, 2016 at 10:58 PM, Cory Quammen <cory.quammen at kitware.com>
> wrote:
>
>> Justin,
>>
>> There is nothing canned in VTK to do this, but with some work you should
>> be able to get there using an implicit function created from your STL file.
>> At a high level, what you would do is create an instance of
>> vtkImplicitPolyDataDistance. Set its input to the poly data from the STL
>> file. Then, create a new point data array in your structured grid that
>> stores the value from the implicit poly data distance filter. Negative
>> values will be inside the poly data, positive values outside, and 0 at the
>> surface. Finally, use vtkClipDataSet to clip the structured grid a function
>> value 0. This should give you back an unstructured grid in approximately
>> the shape of your input STL. It won't be exact because of the interpolation
>> used by vtkClipDataSet, but it should be close.
>>
>> Hope that helps.
>>
>> Cory
>>
>> On Thu, Feb 18, 2016 at 10:08 PM, Justin Weber <onlyjus at gmail.com> wrote:
>>
>>> I would like to generate a "cutcell" mesh using vtk by slicing a
>>> structured grid with polydata loaded from a STL file. The resulting mesh
>>> would be an unstructured grid.
>>>
>>> Are there any tools in vtk to accomplish this?
>>>
>>> I can create the structured grid and polydata successfully. Now I just
>>> need an algorithm to slice the structured mesh with the polydata surface.
>>>
>>> In my searching I could not find anything. However, I could accomplish
>>> this by ray casting to find the intersections between the structured grid
>>> and the polydata. Then using those points to create the unstructured grid.
>>>
>>> See attached 2d sketch.
>>>
>>> Thanks!
>>> Justin
>>>
>>> _______________________________________________
>>> Powered by www.kitware.com
>>>
>>> Visit other Kitware open-source projects at
>>> http://www.kitware.com/opensource/opensource.html
>>>
>>> Please keep messages on-topic and check the VTK FAQ at:
>>> http://www.vtk.org/Wiki/VTK_FAQ
>>>
>>> Search the list archives at: http://markmail.org/search/?q=vtkusers
>>>
>>> Follow this link to subscribe/unsubscribe:
>>> http://public.kitware.com/mailman/listinfo/vtkusers
>>>
>>>
>>
>>
>> --
>> Cory Quammen
>> R&D Engineer
>> Kitware, Inc.
>>
>
>


-- 
Cory Quammen
R&D Engineer
Kitware, Inc.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20160307/c9d56fbb/attachment.html>