The article shows a way to calculate the length between two points on a curve. We create a ring and put axis actor in the center to show the ring’s orientation and size. Here are implementation details, the data file curve.vtp can be downloaded from my github repository documents. #define Read more…
How to set different colors for different parts of a single 3D model? The article introduces a way that set scalars for pointData and map the information by vtkColorTransferFunction object, then vtkPolyDataMapper object configure a correct scalar mode and use vtkColorTransferFunction object as its lookupTable. The code snippet shows all Read more…
I want to rotate the curve to be close to both points, the rotate axis is vector( 0, 0, 1 ) which is Z-axis in VTK’s world coordinate system. We can use the summary of distance squares to indicate the match level, the value is bigger means the curve is Read more…
We can use vtkCoordinate and vtkRenderer objects to convert point’s coordinate from a system to another one. I found vtkCoordinate called the functions of vtkViewport (vtkRenderer is child class of vtkViewport) to accomplish coordinate transformation. class vtkViewport: virtual void LocalDisplayToDisplay(double &x, double &y); virtual void DisplayToNormalizedDisplay(double &u, double &v); virtual Read more…
I want to show png picture by vtkActor2D rather than vtkImageActor or vtkImageViewer. There is not rotating and scaling for the picture when move mouse and click if the vtkActor2D object works. But how to do it? The following project shows axes and a png picture in the window, the Read more…
The article is based on How to use the OpenCV parallel_for_ to parallelize your code, the example project uses OpenCV parallel_for_ to speed up the computing process. Now I plan to use the algorithm class vtkSMPTools in VTK to get the same positive effect. The unit computing task is put Read more…
Development environment: VTK-8.1.1 macOS Catalina 10.15 Python 2.7.10 Configure variables about Qt in CMake GUi fristly. Some details are in the following script file configure.sh. cmake ./ -G “Unix Makefiles” \ -DVTK_USE_QVTK:BOOL=ON \ -DCMAKE_INSTALL_PREFIX=/usr/local \ -DVTK_USE_GUISUPPORT:BOOL=ON \ -DVTK_QT_VERSION=5 \ -DModule_vtkGUISupportQt:BOOL=ON \ -DModule_vtkGUISupportQtOpenGL:BOOL=ON \ -DModule_vtkGUISupportQtSQL:BOOL=ON \ -DModule_vtkGUISupportQtWebkit:BOOL=OFF \ -DModule_vtkRenderingQt:BOOL=ON \ -DModule_vtkViewsQt:BOOL=ON Read more…
I write a small project to create a curve that can be changed and export. The class vtkContourWidget is used to re-construct the curve, vtkXMLPolyDataWriter object helps us to store the polydata. All details for the project had been pushed to GitHub, link: CreateCurve If you fork the repository and Read more…
Store Polydata Some Special polydata can’t be stored by vtkSTLWriter. The following polydata contains points and a line in its structure, it can’t be saved by vtkSTLWriter, but vtkXMLPolyDataWriter works. vtkObject::GlobalWarningDisplayOn(); int numPts = 10; vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New(); int offset = numPts / 4; for (int i = 0; Read more…