# Development

**URL:** https://discourse.vtk.org/c/development/7.md?page=40

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

**Page:** 41

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## [Can the pixel format be changed when renderinig a BGRA bitmap?](https://discourse.vtk.org/t/can-the-pixel-format-be-changed-when-renderinig-a-bgra-bitmap/4682)

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**Author:** [@learn\_forever](https://discourse.vtk.org/u/learn_forever)\
**Replies:** 0\
**Last updated:** [November 18, 2020, 10:14am UTC](https://discourse.vtk.org/t/can-the-pixel-format-be-changed-when-renderinig-a-bgra-bitmap/4682 "2020-11-18T10:14:56Z")

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Hi, I worked on the .NET platform and had a bitmap in memory with BGRA channel in bitmap pixels. In this case, the bitmap will be wrongly rendered inside VTK. So I need to find a way to convert the bitmap pixels from BG…

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## [How to import an PNG file with vtkImageImport?](https://discourse.vtk.org/t/how-to-import-an-png-file-with-vtkimageimport/4667)

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**Author:** [@learn\_forever](https://discourse.vtk.org/u/learn_forever)\
**Replies:** 2\
**Last updated:** [November 17, 2020, 5:58am UTC](https://discourse.vtk.org/t/how-to-import-an-png-file-with-vtkimageimport/4667 "2020-11-17T05:58:22Z")

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Hi, I tried with following code snippet but got a wrong image rendered. MemoryStream ms1 = new MemoryStream(); Image image = Image.FromFile(@"D:\\visual studio 2015\\Projects\\VTKImageBufferRender\\VTKImage…

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## [Layered rendering with multiple renderers](https://discourse.vtk.org/t/layered-rendering-with-multiple-renderers/4670)

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**Author:** [@Faizan](https://discourse.vtk.org/u/Faizan)\
**Replies:** 1\
**Last updated:** [November 17, 2020, 2:04am UTC](https://discourse.vtk.org/t/layered-rendering-with-multiple-renderers/4670 "2020-11-17T02:04:02Z")

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Hello developers, I am stuck in a problem that seems a bit basic but still could not solve it yet. I am using multiple rendering layers to render different kinds of Fiber tracts (Red and orange) overlaid each other. As…

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## [vtkDebugLeaks detects leaks without pattern](https://discourse.vtk.org/t/vtkdebugleaks-detects-leaks-without-pattern/4648)

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**Author:** [@Keyn](https://discourse.vtk.org/u/Keyn)\
**Replies:** 2\
**Last updated:** [November 13, 2020, 6:55pm UTC](https://discourse.vtk.org/t/vtkdebugleaks-detects-leaks-without-pattern/4648 "2020-11-13T18:55:48Z")

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Hello everyone, I have a rather generic question about vtkDebugLeaks. I build vtk 8.2 successfully with it on and was using it for quite some time now. The only report i ever got form vtkDebugLeaks is the following on ex…

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## [Incorrect visualization crossing objects (python, windows, vtk9.0.1)](https://discourse.vtk.org/t/incorrect-visualization-crossing-objects-python-windows-vtk9-0-1/4543)

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**Author:** [@l1va](https://discourse.vtk.org/u/l1va)\
**Replies:** 5\
**Last updated:** [November 12, 2020, 8:08am UTC](https://discourse.vtk.org/t/incorrect-visualization-crossing-objects-python-windows-vtk9-0-1/4543 "2020-11-12T08:08:40Z")

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Good day! I built exe for the windows using cx\_Freeze, python3.8, pyQt5, vtk9.0.1 and see that visualization is not correct. It works correctly for the previous (it might be vtk8.1) version. Cut by plane part of the obj…

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## [Could VTK be used to re-construct colorful 3D using colorful CT images?](https://discourse.vtk.org/t/could-vtk-be-used-to-re-construct-colorful-3d-using-colorful-ct-images/4605)

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**Author:** [@ardeal](https://discourse.vtk.org/u/ardeal)\
**Replies:** 13\
**Last updated:** [November 11, 2020, 3:06pm UTC](https://discourse.vtk.org/t/could-vtk-be-used-to-re-construct-colorful-3d-using-colorful-ct-images/4605 "2020-11-11T15:06:50Z")

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Hi, There are 300 colorful CT slice images. Could I use VTK to re-construct colorful 3D using those colorful CT images? Is there any example code for my reference? Thanks and Best Regards, Ardeal

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## [vtkPlanes not making planes](https://discourse.vtk.org/t/vtkplanes-not-making-planes/4611)

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**Author:** [@Gilthalas](https://discourse.vtk.org/u/Gilthalas)\
**Replies:** 2\
**Last updated:** [November 9, 2020, 7:44pm UTC](https://discourse.vtk.org/t/vtkplanes-not-making-planes/4611 "2020-11-09T19:44:55Z")

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I’m attempting to make a vtkPlanes object with the following Java code: vtkPlanes planes = new vtkPlanes(); planes.SetPoints(planePoints); planes.SetNormals(planeNormals); Where planePoints is a vtkPoints object and pl…

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## [Update of vtkExtractVOI slow in sagittal direction](https://discourse.vtk.org/t/update-of-vtkextractvoi-slow-in-sagittal-direction/4583)

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**Author:** [@Keyn](https://discourse.vtk.org/u/Keyn)\
**Replies:** 8\
**Last updated:** [November 9, 2020, 8:33am UTC](https://discourse.vtk.org/t/update-of-vtkextractvoi-slow-in-sagittal-direction/4583 "2020-11-09T08:33:25Z")

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Hello everyone! I am developing a DICOM viewer/segmentation software in C++, using vtk and vtk-dicom to load the images and OpenCV to process them within an Qt GUI. For the initial loading process, I let a vtkDICOMDire…

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## [Are the coordinate systems of sphere and polyline different?](https://discourse.vtk.org/t/are-the-coordinate-systems-of-sphere-and-polyline-different/4548)

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**Author:** [@clolent](https://discourse.vtk.org/u/clolent)\
**Replies:** 14\
**Last updated:** [November 9, 2020, 6:21am UTC](https://discourse.vtk.org/t/are-the-coordinate-systems-of-sphere-and-polyline-different/4548 "2020-11-09T06:21:55Z")

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Hello, I’m a user who just started using VTK. A problem occurred while trying to create a line and connect it to the center of the sphere. Here’s what happened: poly line RED ( 0,0,-50 ) ~ ( 5,0,-50 ) BLUE ( 0,0,-5…

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## [How to detect if the mouse is over an actor?](https://discourse.vtk.org/t/how-to-detect-if-the-mouse-is-over-an-actor/4572)

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**Author:** [@learn\_forever](https://discourse.vtk.org/u/learn_forever)\
**Replies:** 1\
**Last updated:** [November 5, 2020, 12:32pm UTC](https://discourse.vtk.org/t/how-to-detect-if-the-mouse-is-over-an-actor/4572 "2020-11-05T12:32:01Z")

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I can do this by checking if the actor can be picked during mouse moving. But I don’t think this is an efficient way. So, can any VTK experts give me some suggestions? Thanks a lot.

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## [Modification of array dimension using dataset\_adapter](https://discourse.vtk.org/t/modification-of-array-dimension-using-dataset-adapter/4567)

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**Author:** [@ali.baba](https://discourse.vtk.org/u/ali.baba)\
**Replies:** 0\
**Last updated:** [November 4, 2020, 6:58pm UTC](https://discourse.vtk.org/t/modification-of-array-dimension-using-dataset-adapter/4567 "2020-11-04T18:58:28Z")

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Hi everyone, While using the dataset\_adapter enabling numpy-like access to vtk dataset I have come across an unfortunate behavior. Here is the sequence : u\_grid\_vtk = vtk.vtkUnstructuredGrid() u\_grid = dsa.WrapDataObje…

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## [Rendering PointHandleRepresentation2D with cursor type cause crash!](https://discourse.vtk.org/t/rendering-pointhandlerepresentation2d-with-cursor-type-cause-crash/4538)

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**Author:** [@learn\_forever](https://discourse.vtk.org/u/learn_forever)\
**Replies:** 1\
**Last updated:** [November 1, 2020, 10:05pm UTC](https://discourse.vtk.org/t/rendering-pointhandlerepresentation2d-with-cursor-type-cause-crash/4538 "2020-11-01T22:05:30Z")

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Just run the following codes, you’ll get a nullptr issue. If the PointHandleRepresentation2D doesn’t have an input cursor type, which means , just comment this line code : handleRep-\>SetCursorShape(cursor2D-\>GetOutput())…

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## [vtkActor SetUserMatrix difference/bug(?) since VTK9](https://discourse.vtk.org/t/vtkactor-setusermatrix-difference-bug-since-vtk9/4499)

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**Author:** [@Sophonet](https://discourse.vtk.org/u/Sophonet)\
**Replies:** 2\
**Last updated:** [November 1, 2020, 4:09pm UTC](https://discourse.vtk.org/t/vtkactor-setusermatrix-difference-bug-since-vtk9/4499 "2020-11-01T16:09:30Z")

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Hi VTK team, starting with VTK9, there is an issue/a difference with respect to SetUserMatrix of vtkActor. Earlier (e.g. VTK 8.1.2), the matrix was correctly applied, but now this does not seem to be the case. Has there…

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## [OpenGL errors rendering transparency on mesa](https://discourse.vtk.org/t/opengl-errors-rendering-transparency-on-mesa/4523)

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**Author:** [@andreasbuykx](https://discourse.vtk.org/u/andreasbuykx)\
**Replies:** 4\
**Last updated:** [October 30, 2020, 3:58pm UTC](https://discourse.vtk.org/t/opengl-errors-rendering-transparency-on-mesa/4523 "2020-10-30T15:58:02Z")

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Hi, I’ve posted a question 2 weeks ago in the Support category but did not get a response that got me much further, so I’m trying on Development. I am trying to render transparency with VTK 9.0.1 on Mesa 18.3.4 (also obs…

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## [Backward compatibility](https://discourse.vtk.org/t/backward-compatibility/4512)

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**Author:** [@Frank\_Gao](https://discourse.vtk.org/u/Frank_Gao)\
**Replies:** 10\
**Last updated:** [October 29, 2020, 12:44am UTC](https://discourse.vtk.org/t/backward-compatibility/4512 "2020-10-29T00:44:05Z")

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Hello VTk experts, I have been using VTK V5 for years, wondering if the latest version is backward compatible to V5.2. Any suggestions for upgrade? Your reply is highly appreciated. Thanks, Frank

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## [Convert DICOM data into array (unsigned short \*voxels)](https://discourse.vtk.org/t/convert-dicom-data-into-array-unsigned-short-voxels/4510)

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**Author:** [@Tim\_M](https://discourse.vtk.org/u/Tim_M)\
**Replies:** 0\
**Last updated:** [October 28, 2020, 7:01pm UTC](https://discourse.vtk.org/t/convert-dicom-data-into-array-unsigned-short-voxels/4510 "2020-10-28T19:01:50Z")

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Hi All, I had DICOM data (\*.dcm) files, and I need to get image array data in unsigned short \* format. Is it possible, and how?

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## [Direction of X, Y and Z axis in DICOM patient coordinates](https://discourse.vtk.org/t/direction-of-x-y-and-z-axis-in-dicom-patient-coordinates/4477)

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**Author:** [@Tim\_M](https://discourse.vtk.org/u/Tim_M)\
**Replies:** 2\
**Last updated:** [October 28, 2020, 6:42pm UTC](https://discourse.vtk.org/t/direction-of-x-y-and-z-axis-in-dicom-patient-coordinates/4477 "2020-10-28T18:42:35Z")

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Hi All, I am developing DICOM Viewer with help of VTK/ITK and for one 3D model I need from DICOM data (dcm files) to get Direction of X, Y and Z-axis in DICOM patient coordinates. For this purpose I believe I will need…

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## [VTK Crash on startup with CLR](https://discourse.vtk.org/t/vtk-crash-on-startup-with-clr/4507)

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**Author:** [@RKeene](https://discourse.vtk.org/u/RKeene)\
**Replies:** 0\
**Last updated:** [October 28, 2020, 3:33pm UTC](https://discourse.vtk.org/t/vtk-crash-on-startup-with-clr/4507 "2020-10-28T15:33:49Z")

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I have a Visual C++ program, Visual Studio 2019, WinForms and am trying to add in VTK. I have two projects. One is the CLR project that does the WinForm UI called ORIScanUI, and a second project that does the unmanaged c…

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## [vtkImplicitPlaneWidget2](https://discourse.vtk.org/t/vtkimplicitplanewidget2/3177)

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**Author:** [@Synfony](https://discourse.vtk.org/u/Synfony)\
**Replies:** 2\
**Last updated:** [October 27, 2020, 7:22am UTC](https://discourse.vtk.org/t/vtkimplicitplanewidget2/3177 "2020-10-27T07:22:04Z")

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Hello everyone, I am using the vtkImplicitPlaneWidget2. But, I need to remove the arrow handle. How do I remove the arrow handle? I could not find any single method in the vtkImplicitPlaneWidget2 and vtkImplicitPlaneR…

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## [vtkImageData rendering disappears when viewed from z-axis.](https://discourse.vtk.org/t/vtkimagedata-rendering-disappears-when-viewed-from-z-axis/4480)

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**Author:** [@Velchivz](https://discourse.vtk.org/u/Velchivz)\
**Replies:** 6\
**Last updated:** [October 27, 2020, 12:00am UTC](https://discourse.vtk.org/t/vtkimagedata-rendering-disappears-when-viewed-from-z-axis/4480 "2020-10-27T00:00:54Z")

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When I have an image placed exactly in the XY plane, and I view it from the z-axis. It disappears if there is nothing else in the scene. If I add some other actor, then it does render it. What I’ve noticed is that if I z…

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## [Proposal to change double click event vtk mapping](https://discourse.vtk.org/t/proposal-to-change-double-click-event-vtk-mapping/4120)

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**Author:** [@Davide\_Punzo](https://discourse.vtk.org/u/Davide_Punzo)\
**Replies:** 10\
**Last updated:** [October 22, 2020, 10:51pm UTC](https://discourse.vtk.org/t/proposal-to-change-double-click-event-vtk-mapping/4120 "2020-10-22T22:51:14Z")

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Hi all, for 3DSlicer we use different mapping for double clicks in the QVTKInteractor: we differentiate single and double click events, i.e We would like to merge this PR in vtk upstream since @jcfr is updating the S…

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## [vtkBinnedDecimation](https://discourse.vtk.org/t/vtkbinneddecimation/4463)

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**Author:** [@OdedSudarsky](https://discourse.vtk.org/u/OdedSudarsky)\
**Replies:** 1\
**Last updated:** [October 22, 2020, 4:50am UTC](https://discourse.vtk.org/t/vtkbinneddecimation/4463 "2020-10-22T04:50:06Z")

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vtkBinnedDecimation is claimed to be a polygon mesh decimator with similar results to vtkQuadricClustering, but much faster and with a smaller memory footprint. It already appears in documentation (https://vtk.org/doc/ni…

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## [Interest in GPU image processing pipeline](https://discourse.vtk.org/t/interest-in-gpu-image-processing-pipeline/535)

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**Author:** [@Sunderlandkyl](https://discourse.vtk.org/u/Sunderlandkyl)\
**Replies:** 16\
**Last updated:** [October 21, 2020, 2:46pm UTC](https://discourse.vtk.org/t/interest-in-gpu-image-processing-pipeline/535 "2020-10-21T14:46:02Z")

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Hi all, We have several 3D Slicer related projects which require the use of fast multi-pass GPU-based algorithms. vtkOpenGLImageAlgorithmHelper can be used for this, but it requires that the textures are read back into …

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## [QVTKOpenGLNativeWidget render artefact when printing](https://discourse.vtk.org/t/qvtkopenglnativewidget-render-artefact-when-printing/4441)

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**Author:** [@drpeterfranz](https://discourse.vtk.org/u/drpeterfranz)\
**Replies:** 7\
**Last updated:** [October 21, 2020, 4:11am UTC](https://discourse.vtk.org/t/qvtkopenglnativewidget-render-artefact-when-printing/4441 "2020-10-21T04:11:19Z")

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I am trying to “print” a QVTKOpenGLNativeWidget to a pdf. To achieve this I simply use w-\>render(painter); where w is a QVTKOpenGLNativeWidget and the painter has been created using QPainter painter(dlg.printer())…

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## [Wrapper with VTK-9.0.1 is not generating xml files](https://discourse.vtk.org/t/wrapper-with-vtk-9-0-1-is-not-generating-xml-files/4447)

<div class="topic-metadata">

**Author:** [@abrahamperez](https://discourse.vtk.org/u/abrahamperez)\
**Replies:** 2\
**Last updated:** [October 19, 2020, 8:19pm UTC](https://discourse.vtk.org/t/wrapper-with-vtk-9-0-1-is-not-generating-xml-files/4447 "2020-10-19T20:19:14Z")

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Later than replace VTK\_INCLUDE\_DIRS instead of VTK\_USE\_FILE, CMake is not generating the xml files Some idea?

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## [How to merge two PolyData into one](https://discourse.vtk.org/t/how-to-merge-two-polydata-into-one/4431)

<div class="topic-metadata">

**Author:** [@siaeleni](https://discourse.vtk.org/u/siaeleni)\
**Replies:** 7\
**Last updated:** [October 19, 2020, 12:29pm UTC](https://discourse.vtk.org/t/how-to-merge-two-polydata-into-one/4431 "2020-10-19T12:29:21Z")

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Hello, I would like to merge two vtkpolydata if it is possible, but I want to know at the end which point comes from which dataset. Also, I want to be sure that BuildLinks() will work and be able to find the correct nei…

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## [Porting surface reconstruction to web](https://discourse.vtk.org/t/porting-surface-reconstruction-to-web/4442)

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**Author:** [@SArbabi](https://discourse.vtk.org/u/SArbabi)\
**Replies:** 0\
**Last updated:** [October 19, 2020, 9:00am UTC](https://discourse.vtk.org/t/porting-surface-reconstruction-to-web/4442 "2020-10-19T09:00:54Z")

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Hi, I’m visualizing a point cloud in browser to user, along with a set of controllers that by interacting with them, point cloud gets updated and visualized again in real time. Now I want to visualize the surface inste…

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## [Rendering on multiple GPUs?](https://discourse.vtk.org/t/rendering-on-multiple-gpus/837)

<div class="topic-metadata">

**Author:** [@wokadeh](https://discourse.vtk.org/u/wokadeh)\
**Replies:** 3\
**Last updated:** [October 16, 2020, 3:18am UTC](https://discourse.vtk.org/t/rendering-on-multiple-gpus/837 "2020-10-16T03:18:37Z")

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Dear community, I haven’t started with VTK yet and I am exploring its advantages. My current question is if it possible to render on multiple GPUs. I have a workstation with two nVidia GPUs and want to use its full powe…

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## [vtkSmartVolumeMapper sample distance](https://discourse.vtk.org/t/vtksmartvolumemapper-sample-distance/4375)

<div class="topic-metadata">

**Author:** [@aowen](https://discourse.vtk.org/u/aowen)\
**Replies:** 12\
**Last updated:** [October 14, 2020, 5:48pm UTC](https://discourse.vtk.org/t/vtksmartvolumemapper-sample-distance/4375 "2020-10-14T17:48:17Z")

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I’ve been running into an issue with using the vtkSmartVolumeMapper to visualize datasets that exist in very small ranges. What happens is the opacity changes are very dramatic. If I change the opacity from 100% opaque t…

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## [How to convert a vtkLineSource into vtkImageData,and render like a line not a Cuboid！](https://discourse.vtk.org/t/how-to-convert-a-vtklinesource-into-vtkimagedata-and-render-like-a-line-not-a-cuboid/4413)

<div class="topic-metadata">

**Author:** [@wulicheng](https://discourse.vtk.org/u/wulicheng)\
**Replies:** 0\
**Last updated:** [October 14, 2020, 3:58am UTC](https://discourse.vtk.org/t/how-to-convert-a-vtklinesource-into-vtkimagedata-and-render-like-a-line-not-a-cuboid/4413 "2020-10-14T03:58:18Z")

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