[vtkusers] Re: Question asked by many, answered by none. (Help!)

[Goodwin Lawlor]

Using vtkCleanPolyData before vtkStripper should help.

hth
Goodwin

Ps this was (sort of) answered last year...
http://public.kitware.com/pipermail/vtkusers/2003-February/016061.html

-----Original Message-----
From: vtkusers-admin at vtk.org [mailto:vtkusers-admin at vtk.org] On Behalf
Of vtkusers-request at vtk.org
Sent: 23 March 2004 00:25
To: vtkusers at vtk.org
Subject: vtkusers digest, Vol 1 #2508 - 6 msgs


Message: 5
Date: Mon, 22 Mar 2004 19:21:15 -0500
From: Mathieu Malaterre <mathieu.malaterre at kitware.com>
Organization: Kitware Inc.
To: jarv0075 <jarv0075 at umn.edu>
Cc: vtkusers <vtkusers at vtk.org>
Subject: Re: [vtkusers] Question asked by many, answered by none.
(Help!)

jarv0075,

	Why didn't you used a vtkContourFilter ? I don't see any other
way to 
deal with such difficult polydata

Sorry,
Mathieu

jarv0075 wrote:
> The demo I refer to is the standard 'cow.tcl' demo under the vtkCutter

> examples.  In this, they use the edges from vtkCutter to generate a 
> polyline loop, which works fine for simple polygons but once it 
> encounters holes it seems to be still trying to form one large 
> polyline loop?  When it triangulates, all triangles originate from a 
> single point, and thus it triangulates out to the edges of the holes, 
> and the edges past the holes, making things a total mess (see screen 
> shot)
> 
> The screen shot can be found at 
>   http://www.cs.umn.edu/~tjarvis/tri_fail.jpg
> 
> The error message is as follows:
>   ERROR: In vtkPolygon.cxx, line 1179
>   vtkPolygon (0x818da20): Possible triangulation failure
> 
> I want to be able to cut with the plane, and fill in the slice with 
> some color.  Basically, to be able to triangulate the output of 
> vtkCutter even when holes are present.
> 
> 
> Any help you can offer would be greatly appreciated!
> 
> 
> On 22 Mar 2004, Mathieu Malaterre wrote:
> 
>>jarv0075,
>>
>>	You are loosing me, what 'wonderfully written samples' are you 
>>talking
>>about. Could you please send us a demo + dataset to demonstrate the 
>>problem, or a screenshot.
>>
>>	Thanks
>>Mathieu
>>
>>jarv0075 wrote:
>>
>>> 
>>>The issue is cutting polygonal data with a plane that results in a 
>>>'polygon' with holes in it.  Thus, the wonderfully written samples do
> 
> not
> 
>>>apply, in that the 'sneaky shortcut' of using the edges to make
> 
> polylines
> 
>>>sends the triangulation filter into a tizzy.
>>>
>>>Could someone point me in the right direction on how to triangulate
cut
>>>polydata with holes present?   This does NOT seem like it should be
>>>difficult, but still I've seen the question asked by multiple others
> 
> and
> 
>>>haven't seen one answer surface yet.
>>>
>>>Thank you for your time and patience.