[Insight-users] [vtkusers] AND-filter for vtkPolyData (was extract/selectcoincident points/cells)

Tue Sep 18 02:54:29 EDT 2012

Dear Roman

I seen your mesh data but I am not understand what you want to do ?

1) Do you want to join this two mesh in single ?
2) Because there is only small part to intersection since it's boundary does 
not overlap. See in images has two parts you can see only small part is 
overlap and that will be ur final result
from intersection and that's it producing right now.

Alex

-----Original Message----- 
From: Dr. Roman Grothausmann
Sent: Tuesday, September 18, 2012 11:29 AM
To: alex Dowson
Subject: Re: [vtkusers] AND-filter for vtkPolyData (was 
extract/selectcoincident points/cells)

Dear Alex!

n 18/09/12 06:43, alex Dowson wrote:
> Dear Dr.Roman
>
> can you show picture of your two input mesh or vtp file ?

An visualization and the vtp files are in the tbz of my last post. I
attached them here as well.

Many thanks for looking into this
Roman

>
>
> alex
>
>
>
>
>
>
>
> -----Original Message----- From: Dr. Roman Grothausmann
> Sent: Monday, September 17, 2012 7:03 PM
> To: alexdowson at hotmail.com ; jothybasu at gmail.com
> Cc: VTK Mailing List ; Cory Quammen
> Subject: Re: Fwd: Re: [vtkusers] AND-filter for vtkPolyData (was
> extract/selectcoincident points/cells)
>
> Dear Alex, dear Jothy,
>
>
> Many thanks for Your hint to use vtkBooleanOperationPolyDataFilter for
> this. It basically works but it seems not completely exact. I've
> attached an image that shows two touching blobs (raw meshes generated by
> discreteMarchingCubes, in attached tbz), one is rendered yellow, the
> other as wire frame. The intersection result (code below) of
> vtkBooleanOperationPolyDataFilter is rendered in blue, therefore it
> looks grey where it overlaps with the yellow faces. As you can see, one
> triangle is blue nonetheless. It exists on the blob rendered as wire
> frame but has no counter part on the yellow one, therefore does not
> belong to the set of coincident faces nor does the one corner point
> belong to the set of coincident vertices.
> Since I do not really need a boolean operation (including surface
> intersections) and since Cory Quammen's publication on
> vtkBooleanOperationPolyDataFilter mentions that coplanar face are
> problematic and not treated specially, I thought that
> vtkDistancePolyDataFilter combined with a ThresholdBetween(0.0,0.0) on
> the point-data "Distance" would do the trick. However, I realized from a
> test, that there can be coincident vertices that do not belong to
> coincident faces. Now, I would need a method to find all faces in the
> second mesh which are made up completely by all the vertices from the
> first mesh with "Distance"==0. (Using GetPointCells for all verts with
> "Distance"==0 seems not to help here, since this way "border"
> cells/triangles incorporating only one ore two of the verts are selected
> as well.)
> Using "Distance"==0 for the cell-data, does not work either because it
> contains cell-to-point distance (not cell-to-cell distance). Therefore,
> it needs a ThresholdBetween(0.0, t) where t is slightly greater than 0
> (I used t=0.01 in the code below). As the two meshes originate from
> marching-cubes, I guess an upper limit for t could be deduced from the
> theory which would still grantee that only coincident faces are selected
> this way, but I do not know for sure how to deduce this upper limit for t.
>
> Do You have any ideas how to solve this problem?
>
> Thanks for Your help or hints.
> Roman
>
> /////find and extract coincident vertices and faces of two marching
> cubes meshes
>
> #include <vtkXMLPolyDataReader.h>//for vtp-files
> // #include <vtkPolyDataReader.h>//for vtk-files
> #include <vtkBooleanOperationPolyDataFilter.h>
> #include <vtkXMLPolyDataWriter.h>//for vtp-files
>
> int main(int argc, char* argv[]){
> if( argc <= 3 )
> {
> std::cerr << "Usage: " << argv[0];
> std::cerr << " inputMesh0";
> std::cerr << " inputMesh1";
> std::cerr << " outputMesh";
> std::cerr << std::endl;
> return EXIT_FAILURE;
> }
>
> if(!(strcasestr(argv[1],".vtp"))) {
> std::cout << "The input should end with .vtp" << std::endl;
> return -1;
> }
>
> if(!(strcasestr(argv[2],".vtp"))) {
> std::cout << "The input should end with .vtp" << std::endl;
> return -1;
> }
>
> //vtkPolyDataReader *reader = vtkPolyDataReader::New(); //*.vtk
> vtkXMLPolyDataReader *reader0 = vtkXMLPolyDataReader::New(); //*.vtp
>
> reader0->SetFileName(argv[1]);
> reader0->Update();
>
> vtkXMLPolyDataReader *reader1 = vtkXMLPolyDataReader::New(); //*.vtp
>
> reader1->SetFileName(argv[2]);
> reader1->Update();
>
> vtkBooleanOperationPolyDataFilter *boolean=
> vtkBooleanOperationPolyDataFilter::New();
> boolean->SetInputConnection(0, reader0->GetOutputPort());
> boolean->SetInputConnection(1, reader1->GetOutputPort());
> boolean->SetOperationToIntersection();
>
> vtkXMLPolyDataWriter *Pwriter = vtkXMLPolyDataWriter::New();
> //vtkDataSetWriter *Pwriter = vtkDataSetWriter::New();
>
> Pwriter->SetFileName(argv[3]);
> Pwriter->SetInputConnection(boolean->GetOutputPort(0));
> Pwriter->Update();
>
>
> return EXIT_SUCCESS;
> }
>
> ___________________________________________________________________
>
>
> /////find and extract coincident vertices and faces of two marching
> cubes meshes
> //// there can be coincident verts that do not belong to coincident
> faces!!!
>
>
> #include <vtkXMLPolyDataReader.h>//for vtp-files
> // #include <vtkPolyDataReader.h>//for vtk-files
> //#include <vtkBooleanOperationPolyDataFilter.h>
> #include <vtkDistancePolyDataFilter.h>
> #include <vtkThreshold.h>
> #include <vtkGeometryFilter.h>
> #include <vtkXMLPolyDataWriter.h>//for vtp-files
>
> int main(int argc, char* argv[]){
> if( argc != 4 )
> {
> std::cerr << "Usage: " << argv[0];
> std::cerr << " inputMesh0";
> std::cerr << " inputMesh1";
> std::cerr << " outputMesh";
> std::cerr << std::endl;
> return EXIT_FAILURE;
> }
>
> if(!(strcasestr(argv[1],".vtp"))) {
> std::cout << "The input should end with .vtp" << std::endl;
> return -1;
> }
>
> if(!(strcasestr(argv[2],".vtp"))) {
> std::cout << "The input should end with .vtp" << std::endl;
> return -1;
> }
>
> if(!(strcasestr(argv[3],".vtp"))) {
> std::cout << "The input should end with .vtp" << std::endl;
> return -1;
> }
>
> //vtkPolyDataReader *reader = vtkPolyDataReader::New(); //*.vtk
> vtkXMLPolyDataReader *reader0 = vtkXMLPolyDataReader::New(); //*.vtp
>
> reader0->SetFileName(argv[1]);
> reader0->Update();
>
> vtkXMLPolyDataReader *reader1 = vtkXMLPolyDataReader::New(); //*.vtp
>
> reader1->SetFileName(argv[2]);
> reader1->Update();
>
> vtkDistancePolyDataFilter *polydist= vtkDistancePolyDataFilter::New();
> polydist->SetInputConnection(0, reader0->GetOutputPort());
> polydist->SetInputConnection(1, reader1->GetOutputPort());
> polydist->SignedDistanceOff();
> //polydist->ComputeSecondDistanceOff(); //causes:
> /*
> ERROR: In
> /home/grothama/sda8/programme/VTK/Filtering/vtkExecutive.cxx, line 756
> vtkStreamingDemandDrivenPipeline (0x1d2a800): Algorithm
> vtkDistancePolyDataFilter(0x1d29890) returned failure for request:
> vtkInformation (0x1d4e040)
> Debug: Off
> Modified Time: 757
> Reference Count: 1
> Registered Events: (none)
> Request: REQUEST_DATA
> ALGORITHM_AFTER_FORWARD: 1
> FROM_OUTPUT_PORT: 0
> FORWARD_DIRECTION: 0
> */
> polydist->Update();
>
> vtkThreshold *thresh= vtkThreshold::New();
> thresh->SetInputConnection(polydist->GetOutputPort());
> //thresh->SetInputArrayToProcess(0, 0, 0,
> vtkDataObject::FIELD_ASSOCIATION_POINTS, "Distance"); //
> FIELD_ASSOCIATION_VERTICES
> //thresh->SetInputArrayToProcess(0, 0, 0,
> vtkDataObject::FIELD_ASSOCIATION_POINTS, vtkDataSetAttributes::SCALARS);
> // FIELD_ASSOCIATION_VERTICES
> thresh->SetInputArrayToProcess(0, 0, 0,
> vtkDataObject::FIELD_ASSOCIATION_CELLS, "Distance"); //
> FIELD_ASSOCIATION_VERTICES
> //thresh->SetAttributeModeToUsePointData();
> thresh->ThresholdBetween(0.0,0.01);
>
> vtkGeometryFilter *usg2poly= vtkGeometryFilter::New();
> usg2poly->SetInputConnection(thresh->GetOutputPort());
>
> vtkXMLPolyDataWriter *Pwriter = vtkXMLPolyDataWriter::New();
> //vtkDataSetWriter *Pwriter = vtkDataSetWriter::New();
>
> Pwriter->SetFileName(argv[3]);
> //Pwriter->SetInputConnection(polydist->GetOutputPort());
> Pwriter->SetInputConnection(usg2poly->GetOutputPort());
> Pwriter->Update();
>
>
> return EXIT_SUCCESS;
> }
>
>
>
> On 17/09/12 10:10, Roman Grothausmann wrote:
>>
>>
>>
>> -------- Original Message --------
>> Subject: Re: [vtkusers] AND-filter for vtkPolyData (was
>> extract/selectcoincident points/cells)
>> Date: Wed, 5 Sep 2012 10:49:20 +0200
>> From: Roman Grothausmann <roman.grothausmann at helmholtz-berlin.de>
>> To: alex Dowson <alexdowson at hotmail.com>, VTK Mailing List
>> <vtkusers at vtk.org>
>>
>> Hello Alex,
>>
>>
>> Many thanks for the hint, I had not thought of boolean operation for
>> this since the only overlap, ie the union, would consist only of a
>> surface, not a volume. I'll give it a try and see if it results in what
>> I need. It could work since for the meshes I look at I can rule out that
>> they could also have volume unions.
>>
>> Thanks again for Your hint
>> Roman
>>
>> On 05.09.2012 09:15, alex Dowson wrote:
>>> Hi
>>>
>>> Have you tried CSG Boolean filter in VTK ? Check this class
>>>
>>> http://www.vtk.org/doc/nightly/html/classvtkBooleanOperationPolyDataFilter.html
>>>
>>>
>>>
>>>
>>> Also you can use implicit boolean operation filter for that.
>>>
>>>
>>>
>>>
>>> -----Original Message----- From: Roman Grothausmann
>>> Sent: Wednesday, September 05, 2012 12:42 PM
>>> To: VTK Mailing List
>>> Subject: [vtkusers] AND-filter for vtkPolyData (was
>>> extract/selectcoincident points/cells)
>>>
>>> Dear mailing list members,
>>>
>>>
>>> Is there a kind of AND-filter for vtkPolyData-meshes which I could use
>>> to extract/select coincident points/cells of two meshes?
>>>
>>> Thanks for any hints or help
>>> Roman
>>>
>>> On 31.08.2012 14:53, Roman Grothausmann wrote:
>>>> Dear mailing list members,
>>>>
>>>>
>>>> There are many filters in VTK to clean/merge coincident points but I
>>>> could not find a single filter that extracts/selects coincident
>>>> points/cells.
>>>> I would need it to extract the sub-mesh of two or more
>>>> vtkPolyData-meshes where these meshes overlap, e.g. when a
>>>> vtkDiscreteMarchingCubes surface is generated of two or more labels
>>>> that
>>>> directly touch each other in voxel space.
>>>> Or is there a way to just generate a mesh of the area where both labels
>>>> touch?
>>>>
>>>> Any help or hints are very much appreciated
>>>> Roman
>>>>
>>>
>>
>

-- 
Dr. Roman Grothausmann

Tomographie und Digitale Bildverarbeitung
Tomography and Digital Image Analysis

Institut für Funktionelle und Angewandte Anatomie, OE 4120
Medizinische Hochschule Hannover
Carl-Neuberg-Str. 1
30625 Hannover

Tel. +49 511 532-9574 
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