**Author:** [@janhavi\_deshpande](https://discourse.vtk.org/u/janhavi_deshpande)\
**Replies:** 0\
**Last updated:** [May 12, 2020, 4:55am UTC](https://discourse.vtk.org/t/surface-reconstruction-using-activiz-control/3279 "2020-05-12T04:55:27Z")
Hello, I am trying to render 3D surface using set of contours. I found that surface reconstruction is taking lesser time with activiz control than c++. Why does implementation using activiz takes less time? Also I want …
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## [How to change volume'color ?](https://discourse.vtk.org/t/how-to-change-volumecolor/2061)
**Author:** [@Lee](https://discourse.vtk.org/u/Lee)\
**Replies:** 6\
**Last updated:** [May 11, 2020, 6:43am UTC](https://discourse.vtk.org/t/how-to-change-volumecolor/2061 "2020-05-11T06:43:29Z")
I use ParaView to import RAW file, Its results are as follows： I want to use VTK to simuate this result, Its results are as follows： and i want to change my result’s color ,how to change volume’color ?
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## [vtkCollisionDetectionFilter](https://discourse.vtk.org/t/vtkcollisiondetectionfilter/2594)
**Author:** [@Jaafar\_Nasrabadi](https://discourse.vtk.org/u/Jaafar_Nasrabadi)\
**Replies:** 6\
**Last updated:** [May 11, 2020, 3:46am UTC](https://discourse.vtk.org/t/vtkcollisiondetectionfilter/2594 "2020-05-11T03:46:26Z")
hi i compiled vtk 8.2.0 with cmake and vs 2017 and i tested it. but i can’t see vtkCollisionDetectionFilter. is any special setings needed to compile vtk and use vtkCollisionDetectionFilter? Thanks a lot.
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## [Select points inside a box by custom interactor style](https://discourse.vtk.org/t/select-points-inside-a-box-by-custom-interactor-style/3249)
**Author:** [@sjtu-xx](https://discourse.vtk.org/u/sjtu-xx)\
**Replies:** 0\
**Last updated:** [May 8, 2020, 3:17pm UTC](https://discourse.vtk.org/t/select-points-inside-a-box-by-custom-interactor-style/3249 "2020-05-08T15:17:16Z")
I want to select points inside a box by custom interactor style. To do this, I try to decide if a point inside a defined frustum. The frustum.FunctionValue(pointdata) value of points inside frustum should smaller than ze…
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## [Is there a class to show croocked slice from vtkImageData](https://discourse.vtk.org/t/is-there-a-class-to-show-croocked-slice-from-vtkimagedata/3261)
**Author:** [@kerim](https://discourse.vtk.org/u/kerim)\
**Replies:** 2\
**Last updated:** [May 9, 2020, 9:12pm UTC](https://discourse.vtk.org/t/is-there-a-class-to-show-croocked-slice-from-vtkimagedata/3261 "2020-05-09T21:12:19Z")
Hi, I have 3D data in file that can be displayed as vtkImageData. But I dont want to upload the whole file to the RAM because it weighs few Gigabytes. So I decided to display vertical slice from this file (see picture).…
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## [Can't extract boundary from vtkPolyData](https://discourse.vtk.org/t/cant-extract-boundary-from-vtkpolydata/3258)
**Author:** [@kerim](https://discourse.vtk.org/u/kerim)\
**Replies:** 5\
**Last updated:** [May 9, 2020, 2:14pm UTC](https://discourse.vtk.org/t/cant-extract-boundary-from-vtkpolydata/3258 "2020-05-09T14:14:21Z")
Hi, I’m trying to retrieve boundary points from vtkPolyData but without success. Here is how I try to do that: // here are 9 points (see picture below) vtkSmartPointer\ points = vtkSmartPointe…
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## [Problem with ambient and specular color in vtkLight using vtk 8.2.0 (2)](https://discourse.vtk.org/t/problem-with-ambient-and-specular-color-in-vtklight-using-vtk-8-2-0-2/3204)
**Author:** [@santichialvo](https://discourse.vtk.org/u/santichialvo)\
**Replies:** 8\
**Last updated:** [May 8, 2020, 9:37pm UTC](https://discourse.vtk.org/t/problem-with-ambient-and-specular-color-in-vtklight-using-vtk-8-2-0-2/3204 "2020-05-08T21:37:33Z")
Hello, I’ve some problems related to the methods vtkLight::setSpecularColor and vtkLight::seAmbientColor. I explained the issue in detail in here. I’m not sure if this is a bug, if someone can explain to me what is happ…
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## [How can I use the vtkProbeFilter with a point cloud](https://discourse.vtk.org/t/how-can-i-use-the-vtkprobefilter-with-a-point-cloud/3243)
**Author:** [@timofeymukha](https://discourse.vtk.org/u/timofeymukha)\
**Replies:** 2\
**Last updated:** [May 8, 2020, 8:04am UTC](https://discourse.vtk.org/t/how-can-i-use-the-vtkprobefilter-with-a-point-cloud/3243 "2020-05-08T08:04:31Z")
Dear all, I’m trying to achieve what seems to be an easy task, yet I cannot manage to do it. I have a large polyData, and a large point cloud (a list of points). I want to sample the cell data values of the polyData at …
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## [Data set via SetPixelData / SetRBACharPixelData not shown](https://discourse.vtk.org/t/data-set-via-setpixeldata-setrbacharpixeldata-not-shown/3247)
**Author:** [@codeling](https://discourse.vtk.org/u/codeling)\
**Replies:** 0\
**Last updated:** [May 7, 2020, 8:09pm UTC](https://discourse.vtk.org/t/data-set-via-setpixeldata-setrbacharpixeldata-not-shown/3247 "2020-05-07T20:09:55Z")
I’m trying to use a rubber band selection in one of my render windows. However, while the selection itself works fine, something about this render window prevents the rubber band from being drawn; the selection works as…
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## [Partitioned Unstructured Grid Catalyst](https://discourse.vtk.org/t/partitioned-unstructured-grid-catalyst/3240)
**Author:** [@TakisCFD](https://discourse.vtk.org/u/TakisCFD)\
**Replies:** 0\
**Last updated:** [May 7, 2020, 4:23pm UTC](https://discourse.vtk.org/t/partitioned-unstructured-grid-catalyst/3240 "2020-05-07T16:23:21Z")
Dear All Following a partitioned unstructured grid across processes where the following are true: Each MPI process holds a number of elements Each MPI process holds a number of nodes no ghost nodes mesh geometry remai…
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## [question about the last reslice of vtkResliceImageViewer](https://discourse.vtk.org/t/question-about-the-last-reslice-of-vtkresliceimageviewer/3238)
**Author:** [@yuhuimoon](https://discourse.vtk.org/u/yuhuimoon)\
**Replies:** 0\
**Last updated:** [May 7, 2020, 3:43pm UTC](https://discourse.vtk.org/t/question-about-the-last-reslice-of-vtkresliceimageviewer/3238 "2020-05-07T15:43:47Z")
I’m using vtkResliceImageViewer to show the volume image. I set the viewer to the oblique mode. There are 192 slices in the sagittal direction. When I scroll the viewer to the image by mouse wheel, I can’t get the 192th …
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## [question about image bounds](https://discourse.vtk.org/t/question-about-image-bounds/3231)
**Author:** [@yuhuimoon](https://discourse.vtk.org/u/yuhuimoon)\
**Replies:** 2\
**Last updated:** [May 7, 2020, 3:51pm UTC](https://discourse.vtk.org/t/question-about-image-bounds/3231 "2020-05-07T15:51:53Z")
I have a volume image with the size of 192 x 256 x 256. The spacing of the image is 1. I use GetBounds(). The result is 0, 191, 0, 255, 0, 255. In my understanding, the result should be 0, 192, 0, 256, 0, 256. Is that ri…
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## [Building Python 3 support when building from source](https://discourse.vtk.org/t/building-python-3-support-when-building-from-source/3236)
**Author:** [@mshaikh786](https://discourse.vtk.org/u/mshaikh786)\
**Replies:** 2\
**Last updated:** [May 7, 2020, 3:35pm UTC](https://discourse.vtk.org/t/building-python-3-support-when-building-from-source/3236 "2020-05-07T15:35:29Z")
Hi, I am building VTK 9.0.0 stable release. How do I direct CMake to build Python3 binding? By default it is building python2.7 bindings.
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## [Building VTK 9.0 fails when using mpi support](https://discourse.vtk.org/t/building-vtk-9-0-fails-when-using-mpi-support/3227)
**Author:** [@badshah400](https://discourse.vtk.org/u/badshah400)\
**Replies:** 7\
**Last updated:** [May 7, 2020, 1:32am UTC](https://discourse.vtk.org/t/building-vtk-9-0-fails-when-using-mpi-support/3227 "2020-05-07T01:32:10Z")
When building VTK 9.0 with mpi support, the build fails at linking to generate vtkFiltersParallelGeometryJava with the following errors. Building works without any issue when not compiling with mpi support, which leads m…
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## [Query fraction of rendered pixels](https://discourse.vtk.org/t/query-fraction-of-rendered-pixels/3228)
**Author:** [@woodscn](https://discourse.vtk.org/u/woodscn)\
**Replies:** 0\
**Last updated:** [May 6, 2020, 6:51pm UTC](https://discourse.vtk.org/t/query-fraction-of-rendered-pixels/3228 "2020-05-06T18:51:26Z")
I’m fairly new to VTK, so I apologize if this is already answered somewhere. I’m rendering a large point cloud, and I quickly saturate the screen as the data size increases. I’d like to algorithmically describe this sat…
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## [\[VTK 9.0.0rc3\] Python can't set multisamples](https://discourse.vtk.org/t/vtk-9-0-0rc3-python-cant-set-multisamples/3223)
**Author:** [@jasonb5](https://discourse.vtk.org/u/jasonb5)\
**Replies:** 0\
**Last updated:** [May 6, 2020, 2:32am UTC](https://discourse.vtk.org/t/vtk-9-0-0rc3-python-cant-set-multisamples/3223 "2020-05-06T02:32:20Z")
Calling SetMultiSamples has no affect using VTK 9.0.0rc3. In both examples I would expect the output to show a difference in images but only the 8.2.0 environment produces these results. I’m unsure if i’m using this corr…
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## [vtkClipVolume using an implicit function (vtkCylinder) - errors on output grid](https://discourse.vtk.org/t/vtkclipvolume-using-an-implicit-function-vtkcylinder-errors-on-output-grid/3198)
**Author:** [@vitorvas](https://discourse.vtk.org/u/vitorvas)\
**Replies:** 2\
**Last updated:** [May 6, 2020, 2:43pm UTC](https://discourse.vtk.org/t/vtkclipvolume-using-an-implicit-function-vtkcylinder-errors-on-output-grid/3198 "2020-05-06T14:43:30Z")
Hello! I’m clipping a vtkUnstructuredGrid with a vtkCylinder. I got both parts (making use of GenerateClippedOutputOn()). However, one of my resultant grid has artifacts. I wasn’t able to be sure what are the problem, …
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## [Appending data field to a vtk file (Python VTK)](https://discourse.vtk.org/t/appending-data-field-to-a-vtk-file-python-vtk/3220)
**Author:** [@Shahid](https://discourse.vtk.org/u/Shahid)\
**Replies:** 5\
**Last updated:** [May 6, 2020, 10:02am UTC](https://discourse.vtk.org/t/appending-data-field-to-a-vtk-file-python-vtk/3220 "2020-05-06T10:02:54Z")
Hi I have an array which I wish to add as another data field to an existing vtk file - but im struggling to get it to work. I’m using python, specificaly the build of python and vtk that comes with paraview 5.6.This is …
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## [MPR with vtk-dicom](https://discourse.vtk.org/t/mpr-with-vtk-dicom/3224)
**Author:** [@Yongun\_Lee](https://discourse.vtk.org/u/Yongun_Lee)\
**Replies:** 0\
**Last updated:** [May 6, 2020, 4:46am UTC](https://discourse.vtk.org/t/mpr-with-vtk-dicom/3224 "2020-05-06T04:46:23Z")
Hi. I used d.gobbi’s vtk-dicom and the MPR is showing abnormally. (Annotated Cube faces the Anterior, but the volume faces the person’s right face.) I loaded one series from vtkDICOMReader and applied the coordinate sy…
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## [How to make a DicomImage fill a window](https://discourse.vtk.org/t/how-to-make-a-dicomimage-fill-a-window/3218)
**Author:** [@Amnesie](https://discourse.vtk.org/u/Amnesie)\
**Replies:** 2\
**Last updated:** [May 6, 2020, 2:05am UTC](https://discourse.vtk.org/t/how-to-make-a-dicomimage-fill-a-window/3218 "2020-05-06T02:05:35Z")
Here is my code , vtkSmartPointer imageViewer =vtkSmartPointer::New(); imageViewer-\>SetInputConnection(imageflip-\>GetOutputPort()); imageViewer-\>Render(); imageViewer-\>GetRenderWindow()-\>SetWindowName(“ROI”); imag…
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## [Deleting points from vtkPolyData](https://discourse.vtk.org/t/deleting-points-from-vtkpolydata/3222)
**Author:** [@MMoussa](https://discourse.vtk.org/u/MMoussa)\
**Replies:** 0\
**Last updated:** [May 6, 2020, 12:25am UTC](https://discourse.vtk.org/t/deleting-points-from-vtkpolydata/3222 "2020-05-06T00:25:30Z")
Brand new to VTK I am using the C# wrapper (Activiz) to build an interactive application. I’m trying to figure out how to delete points from vtkPolyData (more generally, how to efficiently use this data structure in an …
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## [How to compute surface- and volume-based center of masses for 3D geometries](https://discourse.vtk.org/t/how-to-compute-surface-and-volume-based-center-of-masses-for-3d-geometries/3215)
**Author:** [@normanius](https://discourse.vtk.org/u/normanius)\
**Replies:** 3\
**Last updated:** [May 5, 2020, 11:05pm UTC](https://discourse.vtk.org/t/how-to-compute-surface-and-volume-based-center-of-masses-for-3d-geometries/3215 "2020-05-05T23:05:04Z")
Hello For (closed) 3D surface geometries with triangular mesh, I can think of three different types to compute the “center of mass”: point-based: center=sum(points)/len(points) surface-based: center=sum(tri\_areas\*tri…
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## [Vtk threshold not passing cell and point data](https://discourse.vtk.org/t/vtk-threshold-not-passing-cell-and-point-data/3188)
**Author:** [@a-jp1](https://discourse.vtk.org/u/a-jp1)\
**Replies:** 1\
**Last updated:** [May 5, 2020, 9:40pm UTC](https://discourse.vtk.org/t/vtk-threshold-not-passing-cell-and-point-data/3188 "2020-05-05T21:40:01Z")
Hi, I’m sure I’ve done this before in c++ with vtk. Have a vtkunstructuredgrid that I threshold on a cell based int array. There is other cell and point data on the mesh but it’s not being passed. If I do the same opt…
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## [Adding center of mass properties to vtkMassProperties](https://discourse.vtk.org/t/adding-center-of-mass-properties-to-vtkmassproperties/653)
**Author:** [@rdbrn](https://discourse.vtk.org/u/rdbrn)\
**Replies:** 1\
**Last updated:** [May 5, 2020, 2:28pm UTC](https://discourse.vtk.org/t/adding-center-of-mass-properties-to-vtkmassproperties/653 "2020-05-05T14:28:27Z")
I propose to add VolumeCenterX, VolumeCenterY and VolumeCenterZ to vtkMassProperties. These properties are easy to calculate as follows: for each triangle: create a tetrahedron for the three vertices of this triangle …
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## [Marking algorithm output as unchanged](https://discourse.vtk.org/t/marking-algorithm-output-as-unchanged/3210)
**Author:** [@BetaRavener](https://discourse.vtk.org/u/BetaRavener)\
**Replies:** 0\
**Last updated:** [May 5, 2020, 9:59am UTC](https://discourse.vtk.org/t/marking-algorithm-output-as-unchanged/3210 "2020-05-05T09:59:28Z")
Hi. I have a situation in which I have a two filters and a time-aware source. Source (A) is connected to first filter (B), which filters the data based on some criteria. Output of B is connected to computationally heavy …
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## [How to implement a vtkImageData with boolean data?](https://discourse.vtk.org/t/how-to-implement-a-vtkimagedata-with-boolean-data/3209)
**Author:** [@MichelleKline](https://discourse.vtk.org/u/MichelleKline)\
**Replies:** 2\
**Last updated:** [May 5, 2020, 12:00am UTC](https://discourse.vtk.org/t/how-to-implement-a-vtkimagedata-with-boolean-data/3209 "2020-05-05T00:00:17Z")
Hello, Is it possible to create a vtkImageData with boolean data? For example: myImage = vtkSmartPointer\::New(); myImage-\>AllocateScalars(VTK\_FLOAT, 1); // is boolean possible? Thank you, Michelle
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## [VolumeRendering Window Width and Window Level using VTK](https://discourse.vtk.org/t/volumerendering-window-width-and-window-level-using-vtk/3200)
**Author:** [@watson](https://discourse.vtk.org/u/watson)\
**Replies:** 1\
**Last updated:** [May 4, 2020, 11:40pm UTC](https://discourse.vtk.org/t/volumerendering-window-width-and-window-level-using-vtk/3200 "2020-05-04T23:40:18Z")
I need to change the Window Width and Window Level of the volume rendered image with mouse using vtk . I referred this link https://vtk.org/pipermail/vtkusers/2015-September/092338.html .But it has no precise answer. H…
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## [Does Slicer Allow Us to Export a Single Slice?](https://discourse.vtk.org/t/does-slicer-allow-us-to-export-a-single-slice/3158)
**Author:** [@MichelleKline](https://discourse.vtk.org/u/MichelleKline)\
**Replies:** 3\
**Last updated:** [May 4, 2020, 11:08pm UTC](https://discourse.vtk.org/t/does-slicer-allow-us-to-export-a-single-slice/3158 "2020-05-04T23:08:37Z")
Hello, Is there a way in Slicer to export the currently displayed (and likely reformatted) slice of a volume to an output file? For example, I have loaded a double-oblique DICOM, and I am viewing the volume in an axial…
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## [Problem with ambient and specular color in vtkLight using vtk 8.2.0](https://discourse.vtk.org/t/problem-with-ambient-and-specular-color-in-vtklight-using-vtk-8-2-0/2566)
**Author:** [@santichialvo](https://discourse.vtk.org/u/santichialvo)\
**Replies:** 6\
**Last updated:** [May 4, 2020, 3:09pm UTC](https://discourse.vtk.org/t/problem-with-ambient-and-specular-color-in-vtklight-using-vtk-8-2-0/2566 "2020-05-04T15:09:11Z")
Hi all, I recently migrated from VTK 6.3 to 8.2. I use two lights on the scene, and I have a small UI option to change the value of the components of the light. For this purpose, I use SetXXXColor() method. It’s strange…
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## [Manipulate data from a vtkXMLUnstructuredGridReader](https://discourse.vtk.org/t/manipulate-data-from-a-vtkxmlunstructuredgridreader/3179)
**Author:** [@armel.demontgros](https://discourse.vtk.org/u/armel.demontgros)\
**Replies:** 6\
**Last updated:** [May 3, 2020, 9:36pm UTC](https://discourse.vtk.org/t/manipulate-data-from-a-vtkxmlunstructuredgridreader/3179 "2020-05-03T21:36:28Z")
Hi, I am wondering what is the best way to manipulate the data coming from a vtkXMLUnstructuredGridReader. std::string filename = “C:\\VTK\\exm.vtu”; vtkNew reader; reader-\>SetFileName(filename.c\_str()); reader-\>Updat…
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