# Latest

**URL:** https://discourse.vtk.org/latest.md?page=115

[Latest](https://discourse.vtk.org/latest.md) · [Categories](https://discourse.vtk.org/categories.md) · [Tags](https://discourse.vtk.org/tags.md)

**Page:** 116

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## [Strange Shader Behavior With VTK and WebAssembly](https://discourse.vtk.org/t/strange-shader-behavior-with-vtk-and-webassembly/4183)

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**Author:** [@Donny\_Zimmerman](https://discourse.vtk.org/u/Donny_Zimmerman)\
**Replies:** 8\
**Last updated:** [October 9, 2022, 2:49am UTC](https://discourse.vtk.org/t/strange-shader-behavior-with-vtk-and-webassembly/4183 "2022-10-09T02:49:09Z")

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I have some code that reads a .vtp file with vtkXMLPolyDataReader that contains lines. I can run the code and see the lines with my desktop app, but when I compile it to WebAssembly I get the following error when running…

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## [Convert numpy landmarks point coordinates to VTK.Polydata, and align them using the vtkProcrustesAlignmentFilter ()](https://discourse.vtk.org/t/convert-numpy-landmarks-point-coordinates-to-vtk-polydata-and-align-them-using-the-vtkprocrustesalignmentfilter/9543)

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**Author:** [@joy](https://discourse.vtk.org/u/joy)\
**Replies:** 0\
**Last updated:** [October 7, 2022, 8:12am UTC](https://discourse.vtk.org/t/convert-numpy-landmarks-point-coordinates-to-vtk-polydata-and-align-them-using-the-vtkprocrustesalignmentfilter/9543 "2022-10-07T08:12:29Z")

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Hello VTK Team, I am new to VTK, I want to use the vtkProcrustesAlignmentFilter () for aligning multiple landmark points. I use these codes to do it? import numpy as np import open3d as o3d import pyvista as pv impor…

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## [VTK 9.2.2 is out](https://discourse.vtk.org/t/vtk-9-2-2-is-out/9520)

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**Author:** [@ben.boeckel](https://discourse.vtk.org/u/ben.boeckel)\
**Replies:** 7\
**Last updated:** [October 7, 2022, 1:05pm UTC](https://discourse.vtk.org/t/vtk-9-2-2-is-out/9520 "2022-10-07T13:05:14Z")

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VTK 9.2.2 is finally out. This release comes with Python wheels for Python 3.10 and SDKs for building further wheels based on VTK’s C++ API. Python 3.11 is not included as our dependencies don’t seem to be ready yet. Do…

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## [Need help with volume rendering parameters](https://discourse.vtk.org/t/need-help-with-volume-rendering-parameters/9477)

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**Author:** [@gzt036](https://discourse.vtk.org/u/gzt036)\
**Replies:** 7\
**Last updated:** [October 7, 2022, 6:12am UTC](https://discourse.vtk.org/t/need-help-with-volume-rendering-parameters/9477 "2022-10-07T06:12:30Z")

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when I first load the vtk volume it loads ok but not with the desired opacity. but once I do any mouse operation, e.g., rotation, pan, or dolly, it renders with the desired effect Could someone tell me what’s the d…

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## [Determine point inside/outside enclosed surface](https://discourse.vtk.org/t/determine-point-inside-outside-enclosed-surface/9539)

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**Author:** [@drpeterfranz](https://discourse.vtk.org/u/drpeterfranz)\
**Replies:** 9\
**Last updated:** [October 7, 2022, 2:13am UTC](https://discourse.vtk.org/t/determine-point-inside-outside-enclosed-surface/9539 "2022-10-07T02:13:03Z")

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Hi there, I have a problem here we my application receives a triangulated, closed surface which encloses a volume. The resolution of this surface is high, i.e. there are \> 100,000 triangles in it, and it can be concave.…

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## [Maximum Intensity Projection](https://discourse.vtk.org/t/maximum-intensity-projection/6514)

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**Author:** [@aleena98](https://discourse.vtk.org/u/aleena98)\
**Replies:** 5\
**Last updated:** [October 6, 2022, 8:56pm UTC](https://discourse.vtk.org/t/maximum-intensity-projection/6514 "2022-10-06T20:56:02Z")

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I am working on a project to detect cerebral aneurysm using UNET CNN. I am using MRA images in this project. I would need to convert the 3D images into 2D images before feeding it into the neural network or get MIP for t…

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## [Reading and rendering a digital elevation model (DEM) in VTK](https://discourse.vtk.org/t/reading-and-rendering-a-digital-elevation-model-dem-in-vtk/9536)

<div class="topic-metadata">

**Author:** [@llobera](https://discourse.vtk.org/u/llobera)\
**Replies:** 0\
**Last updated:** [October 6, 2022, 11:05am UTC](https://discourse.vtk.org/t/reading-and-rendering-a-digital-elevation-model-dem-in-vtk/9536 "2022-10-06T11:05:16Z")

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I have a few questions regarding how to best generate a 3D rendering of digital elevation model (DEM). Is there a way to access via python bindings the GDALRasterReader() function? This functionality appears in VTK but…

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## [Possible bug in vtkStringArray](https://discourse.vtk.org/t/possible-bug-in-vtkstringarray/9528)

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**Author:** [@MarKara](https://discourse.vtk.org/u/MarKara)\
**Replies:** 3\
**Last updated:** [October 6, 2022, 6:02am UTC](https://discourse.vtk.org/t/possible-bug-in-vtkstringarray/9528 "2022-10-06T06:02:34Z")

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Hi I recently moved from Activiz 6.3 to 9.3 and discovered possible bug in compiled vtkStringArray. Here is the test vtkStringArray stringArray = new vtkStringArray(); stringArray.SetNumberOfValues(3); stringArray.…

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## [VTK-PROJ simple example not working](https://discourse.vtk.org/t/vtk-proj-simple-example-not-working/9532)

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**Author:** [@Tomasso](https://discourse.vtk.org/u/Tomasso)\
**Replies:** 6\
**Last updated:** [October 6, 2022, 1:12am UTC](https://discourse.vtk.org/t/vtk-proj-simple-example-not-working/9532 "2022-10-06T01:12:03Z")

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VTK source comes with self-contained PROJ source, in directory ThirdParty/libproj, and library libvtklibproj.so is built from that. Compiling application C++ code with this flag enables VTK PROJ headers and the aforemen…

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## [Selecting random points of a PolyData (Stratified sampling)](https://discourse.vtk.org/t/selecting-random-points-of-a-polydata-stratified-sampling/7003)

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**Author:** [@mau\_igna\_06](https://discourse.vtk.org/u/mau_igna_06)\
**Replies:** 33\
**Last updated:** [October 5, 2022, 6:11pm UTC](https://discourse.vtk.org/t/selecting-random-points-of-a-polydata-stratified-sampling/7003 "2022-10-05T18:11:06Z")

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Hi. I would like to know how to get a sample of points of my polydata that are evenly distributed on the mesh surface. My input is a longBonePolyData. Here is my code till now: desiredNumberOfPoints = 1000 ratio = int(…

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## [How to actually to convert 3d numpy array of DICOM images into vtkImageData and vtkAlgorithmOutput?](https://discourse.vtk.org/t/how-to-actually-to-convert-3d-numpy-array-of-dicom-images-into-vtkimagedata-and-vtkalgorithmoutput/9529)

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**Author:** [@BJladika](https://discourse.vtk.org/u/BJladika)\
**Replies:** 2\
**Last updated:** [October 5, 2022, 2:23pm UTC](https://discourse.vtk.org/t/how-to-actually-to-convert-3d-numpy-array-of-dicom-images-into-vtkimagedata-and-vtkalgorithmoutput/9529 "2022-10-05T14:23:06Z")

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As I’ve previously in other topic mentioned, I have a vtkResliceCursor, which uses vtkImageData and vtkAlgorithmOutput. Both were provided by vtkDICOMImageReader but it had few flaws. So I’ve decided to generate a 3d num…

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## [Zero input connections are not optional](https://discourse.vtk.org/t/zero-input-connections-are-not-optional/1500)

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**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 2\
**Last updated:** [February 21, 2021, 6:00am UTC](https://discourse.vtk.org/t/zero-input-connections-are-not-optional/1500 "2021-02-21T06:00:47Z")

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Hi, I have a program where the user will enter varying number of volumes to merge into one volume using BooleanOperationPolyDataFilter. I have two vtkBooleanOperationPolyDataFilter and depending on the situation, some p…

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## [Possible issue in vtkloguru with musl in 9.1.0](https://discourse.vtk.org/t/possible-issue-in-vtkloguru-with-musl-in-9-1-0/9526)

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**Author:** [@waebbl](https://discourse.vtk.org/u/waebbl)\
**Replies:** 5\
**Last updated:** [October 4, 2022, 8:41pm UTC](https://discourse.vtk.org/t/possible-issue-in-vtkloguru-with-musl-in-9-1-0/9526 "2022-10-04T20:41:42Z")

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Hello, I received a bug report from a machine running musl when building vtkloguru module\[1\]. After looking into this, I noticed, there’s some logic in KWSys which handles missing execinfo.h properly. The build log att…

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## [Possible inconsistency in vtknetcdf?](https://discourse.vtk.org/t/possible-inconsistency-in-vtknetcdf/9514)

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**Author:** [@waebbl](https://discourse.vtk.org/u/waebbl)\
**Replies:** 4\
**Last updated:** [October 4, 2022, 4:23pm UTC](https://discourse.vtk.org/t/possible-inconsistency-in-vtknetcdf/9514 "2022-10-04T16:23:21Z")

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The VERSION variable in ThirdParty/netcdf/vtknetcdf/CMakeLists.txt is being set to be 4.8.1. However the PACKAGE\_VERSION is defined to be “4.5.0”\[1\]. Is this correct? \[1\] https://gitlab.kitware.com/vtk/vtk/-/blob/master…

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## [DataArray getRange behaviour with NaN](https://discourse.vtk.org/t/dataarray-getrange-behaviour-with-nan/9525)

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**Author:** [@zaidb](https://discourse.vtk.org/u/zaidb)\
**Replies:** 1\
**Last updated:** [October 4, 2022, 2:47pm UTC](https://discourse.vtk.org/t/dataarray-getrange-behaviour-with-nan/9525 "2022-10-04T14:47:10Z")

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Hello, When defining a vtkDataArray with NaN, getRange returns \[NaN, NaN\]. const data = \[NaN, 1, 0, 100\]; const scalar = vtkDataArray.newInstance({ name: "test", values: data }); I guess this is a wanted b…

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## [Obtaining multiple z-buffers after rotating camera](https://discourse.vtk.org/t/obtaining-multiple-z-buffers-after-rotating-camera/9503)

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**Author:** [@llobera](https://discourse.vtk.org/u/llobera)\
**Replies:** 1\
**Last updated:** [October 3, 2022, 7:09pm UTC](https://discourse.vtk.org/t/obtaining-multiple-z-buffers-after-rotating-camera/9503 "2022-10-03T19:09:21Z")

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I would like to be able to capture the z-buffer for different planes around my camera position. Once centered on one direction I would like to make a call back what rotate the camera by a certain number of degrees and du…

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## [Bug in RemoteView Example (vtk.js)](https://discourse.vtk.org/t/bug-in-remoteview-example-vtk-js/9523)

<div class="topic-metadata">

**Author:** [@Kenneth\_Nielsen](https://discourse.vtk.org/u/Kenneth_Nielsen)\
**Replies:** 3\
**Last updated:** [October 3, 2022, 3:47pm UTC](https://discourse.vtk.org/t/bug-in-remoteview-example-vtk-js/9523 "2022-10-03T15:47:49Z")

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Hi VTK. There seems to have been introduced a bug in the The example worked earlier this year, but after some of the recent updates, something seems to have broken it. After debugging a local version, it seems that i…

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## [vtkDICOMImageReader function SetFileNames is not working?](https://discourse.vtk.org/t/vtkdicomimagereader-function-setfilenames-is-not-working/9521)

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**Author:** [@BJladika](https://discourse.vtk.org/u/BJladika)\
**Replies:** 1\
**Last updated:** [October 3, 2022, 3:44pm UTC](https://discourse.vtk.org/t/vtkdicomimagereader-function-setfilenames-is-not-working/9521 "2022-10-03T15:44:45Z")

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So I have stumbled on example of vtkResliceCursor which uses a vtkDICOMImageReader function SetDirectoryName for generating output. And I have a set of DICOM Files. reader = vtkDICOMImageReader(); reader.SetDirectoryNam…

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## [Render backing image vtkjs](https://discourse.vtk.org/t/render-backing-image-vtkjs/8860)

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**Author:** [@stu039](https://discourse.vtk.org/u/stu039)\
**Replies:** 8\
**Last updated:** [October 3, 2022, 2:12pm UTC](https://discourse.vtk.org/t/render-backing-image-vtkjs/8860 "2022-10-03T14:12:26Z")

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Hi there, I am looking to add some backing images to some polydata objects. I currently have the images in png format & I can see that vtk js does not yet have a png image reader implemented. Is there any alternative …

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## [VTK 9.2 Can't Compile PolyLine Example](https://discourse.vtk.org/t/vtk-9-2-cant-compile-polyline-example/9508)

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**Author:** [@jzhang](https://discourse.vtk.org/u/jzhang)\
**Replies:** 3\
**Last updated:** [October 3, 2022, 5:50am UTC](https://discourse.vtk.org/t/vtk-9-2-cant-compile-polyline-example/9508 "2022-10-03T05:50:07Z")

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I’m trying to build a project that sends a PolyData message over IGTLink. However, when I copied over the C++ example for PolyLine, I get an error on the following line: polyLine-\>GetPointIds()-\>SetNumberOfIds(2) The e…

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## [VTK.JS Setting CubeSource Edge Width and Color](https://discourse.vtk.org/t/vtk-js-setting-cubesource-edge-width-and-color/7187)

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**Author:** [@simplyvish](https://discourse.vtk.org/u/simplyvish)\
**Replies:** 12\
**Last updated:** [October 1, 2022, 4:49am UTC](https://discourse.vtk.org/t/vtk-js-setting-cubesource-edge-width-and-color/7187 "2022-10-01T04:49:34Z")

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Hi, I’m a newbie to image rendering and to vtk.js. I was trying the inbuilt VolumeViewer example and after some efforts was able to run it. Now, I’m creating a bounding box at required position in the the vti file render…

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## [VTK 9.2.0 Release Cycle](https://discourse.vtk.org/t/vtk-9-2-0-release-cycle/8149)

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**Author:** [@ben.boeckel](https://discourse.vtk.org/u/ben.boeckel)\
**Replies:** 9\
**Last updated:** [September 30, 2022, 6:49pm UTC](https://discourse.vtk.org/t/vtk-9-2-0-release-cycle/8149 "2022-09-30T18:49:21Z")

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Hi all, It’s about time for another VTK release. The CI dashboards have been stabilizing fairly well with just one flaky test (being excluded here) and it seems like a good time to start cutting a release. Tentative da…

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## [Orientation of plot within vtkChartMatrix](https://discourse.vtk.org/t/orientation-of-plot-within-vtkchartmatrix/1538)

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**Author:** [@marco.reato](https://discourse.vtk.org/u/marco.reato)\
**Replies:** 1\
**Last updated:** [September 30, 2022, 9:18am UTC](https://discourse.vtk.org/t/orientation-of-plot-within-vtkchartmatrix/1538 "2022-09-30T09:18:04Z")

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Hello everyone, I’m currently building some 2D data visualization tools based on the vtkChartXY and vtkChartMatrix classes. I’ve started by looking at these two examples: https://lorensen.github.io/VTKExamples/site/Cx…

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## [vtkRectf and vtkRectd not available in Java wrapper](https://discourse.vtk.org/t/vtkrectf-and-vtkrectd-not-available-in-java-wrapper/9486)

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**Author:** [@Martin3d](https://discourse.vtk.org/u/Martin3d)\
**Replies:** 3\
**Last updated:** [September 29, 2022, 1:04pm UTC](https://discourse.vtk.org/t/vtkrectf-and-vtkrectd-not-available-in-java-wrapper/9486 "2022-09-29T13:04:03Z")

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Hi, As the title said, I can’t find vtkRectf neither vtkRectd in the Java generated wrapper… although I get a java file generated for vtkRect. However the generated java class is not public hence can not be imported. L…

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## [Polygon edges are not rendering properly](https://discourse.vtk.org/t/polygon-edges-are-not-rendering-properly/9494)

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**Author:** [@manoj.lad](https://discourse.vtk.org/u/manoj.lad)\
**Replies:** 0\
**Last updated:** [September 29, 2022, 7:42am UTC](https://discourse.vtk.org/t/polygon-edges-are-not-rendering-properly/9494 "2022-09-29T07:42:24Z")

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Hello, We have recently switched from VTK 7.0.0 to VTK 9.2.0. We have to show meshed face. For that we have used following code. We are using QT 6.3.2 for our application. vtkPolyData\* polyData = vtkPolyData::New…

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## [Failed to inherit vtkRenderer](https://discourse.vtk.org/t/failed-to-inherit-vtkrenderer/9481)

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**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 2\
**Last updated:** [September 29, 2022, 7:22am UTC](https://discourse.vtk.org/t/failed-to-inherit-vtkrenderer/9481 "2022-09-29T07:22:09Z")

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I want to write a class which inherit from vtkRenderer. My code is: #include \<vtkAutoInit.h\> VTK\_MODULE\_INIT(vtkRenderingOpenGL2); VTK\_MODULE\_INIT(vtkInteractionStyle); VTK\_MODULE\_INIT(vtkRenderingVolumeOpenGL2); VTK\_M…

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## [Bool operation between concave poly and cube](https://discourse.vtk.org/t/bool-operation-between-concave-poly-and-cube/9489)

<div class="topic-metadata">

**Author:** [@lele.wang](https://discourse.vtk.org/u/lele.wang)\
**Replies:** 0\
**Last updated:** [September 29, 2022, 3:41am UTC](https://discourse.vtk.org/t/bool-operation-between-concave-poly-and-cube/9489 "2022-09-29T03:41:44Z")

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Hi all, I tried to use a concave body and a cube for Boolean calculation and difference. Before calculation, I used vtkTriangleFilter to triangulate them respectively. The calculated results are not what I want。 Any…

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## [Possible timeout in parseAsArrayBuffer](https://discourse.vtk.org/t/possible-timeout-in-parseasarraybuffer/9470)

<div class="topic-metadata">

**Author:** [@riddlexter](https://discourse.vtk.org/u/riddlexter)\
**Replies:** 4\
**Last updated:** [September 28, 2022, 7:51pm UTC](https://discourse.vtk.org/t/possible-timeout-in-parseasarraybuffer/9470 "2022-09-28T19:51:10Z")

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Is there a timeout in parseAsArrayBuffer from ITKImageReader? Because when I try to get data from a slow server it gives error in Promise, but if I get the same file from a local server it works well, no problems, both u…

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## [Read image data from RAM](https://discourse.vtk.org/t/read-image-data-from-ram/9412)

<div class="topic-metadata">

**Author:** [@masoud](https://discourse.vtk.org/u/masoud)\
**Replies:** 3\
**Last updated:** [September 28, 2022, 6:11pm UTC](https://discourse.vtk.org/t/read-image-data-from-ram/9412 "2022-09-28T18:11:53Z")

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Dear all, I was willing to build a Dicom image viewer using vtk (more specifically Activiz) and could build it successfully. vtkDicomImageReader can read standard Dicom format but cannot read other formats. This means t…

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## [vtk how to prevent the blur edge?](https://discourse.vtk.org/t/vtk-how-to-prevent-the-blur-edge/9484)

<div class="topic-metadata">

**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 0\
**Last updated:** [September 28, 2022, 9:52am UTC](https://discourse.vtk.org/t/vtk-how-to-prevent-the-blur-edge/9484 "2022-09-28T09:52:25Z")

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I want to display a color image and a gray image. The code is about (python): grayActor = ... colorActor = ... render.AddActor(grayActor) render.AddActor(colorActor ) And the result is shown as the above picture. …

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