[vtkusers] vtkCutter leaves "gaps"

[David Gobbi]

Hi Gerrick,

The cutter algorithm is fairly straightforward, it just creates a new point
along each edge that is intersected by the plane.  Then it uses its
knowledge about the connectivity of the original cells to join the new
points together to create new cells.

The only problem I've ever seen with vtkCutter is the fact that its locator
is limited by numerical precision: it might think two cells share an edge
when in fact the edges are just very, very close to each other.  But the
result of this is that gaps are closed, not created.

In response to the question about whether I've ever seen vtkCutter create
gaps where no gaps exist in the original data, I'd have to say no.  That's
not to say that it could never happen.  The vtkCutter delegates the
"cutting" to the Contour methods of the various cell classes, so it is
possible that your data uses a cell type with a buggy Contour
implementation.  If that is the case, it would be good to know the details
of your data so that someone can investigate, but my first suspicion is
that the gaps are present in your original data.

  David


On Fri, Dec 6, 2013 at 11:13 AM, Bill Lorensen <bill.lorensen at gmail.com>wrote:

> I do not see the attachment/
>
>
>
> On Fri, Dec 6, 2013 at 12:50 PM, Gerrick Bivins <
> Gerrick.Bivins at halliburton.com> wrote:
>
>>  I realized I sent this at a time when most people were probably offline.
>>
>> Just a “BUMP” in case this got missed.
>>
>> Anyone have any ideas here?
>>
>> Gerrick
>>
>> *From:* vtkusers-bounces at vtk.org [mailto:vtkusers-bounces at vtk.org] *On
>> Behalf Of *Gerrick Bivins
>> *Sent:* Monday, November 25, 2013 8:33 AM
>> *To:* 'vtkusers at vtk.org'
>> *Subject:* [vtkusers] vtkCutter leaves "gaps"
>>
>>
>>
>> Hi All,
>>
>> I’ve run into a strange problem where with some of my datasets, vtkCutter
>> is leaving “gaps” in the output polydata.
>>
>> For example, if I use a plane as the implicit function the attached image
>> shows the result.
>>
>> Anyone seen this kind of  behavior before?
>>
>> Is there some setting on the vtkCutter that is perhaps causing this?
>>
>>
>>
>> Gerrick
>>
>>
>>
>>
>>
>>
>>
>> [image: DecisionSpace® 5000.8.3 Now Available]<https://www.landmarksoftware.com/Pages/Geosciences.aspx>
>>
>>
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