We have to clear actors in vtkCellPicker object before InitializePickList. In the function Pick, the picker object will addItem to increase its reference count. So we need to do the following tasks for picker object in class destructor function to avoid crash or weird visible bug.
The post shows how to generate an oriented bounding box based on the three axis known in advance. The 3D model is displayed by a CUModel object. We will calculate the two farthest points, positive farthest point and negative farthest point along the special direction. Then generate a polydata from Read more…
I mainly focus on coding for software development at work. If we need some complicated 3D models, other colleagues in charge of data production will provide relevant model files. 在工作的时候，我们做软件研发主要专注于代码编写，如果需要一些复杂的3D模型的话，则要负责数据生产的同事提供相关的模型文件。 But sometimes they give us a model that’s not at the ideal position in the 3D world, and I often Read more…
There are many magical properties in matrix computation, such as: AB != BA A != 0, B != 0, but maybe AB = 0. AB = AC, A != 0, but we can’t get that B = C. People couldn’t understand why it was so different from ordinary numerical calculations Read more…
As we know, we can create a linear transform to change model to the special orientation and position. Refer to The Releationship Between Local Transform And Pose Transform. Let’s define orientation and position by three axis and point. , , and origin = . The matrix for the linear transform Read more…
Here is a example that vtkTransform object failed to deep copy the other one. #include <iostream> #include <vtkSmartPointer.h> #include <vtkRenderer.h> #include <vtkRenderWindow.h> #include <vtkTransform.h> #define vtkSPtr vtkSmartPointer #define vtkSPtrNew(Var, Type) vtkSPtr<Type> Var = vtkSPtr<Type>::New(); int main() { setbuf( stdout, nullptr ); vtkSPtrNew( trans, vtkTransform ); auto matrix = trans->GetMatrix(); matrix->SetElement( Read more…
You can use the key ‘i’ to enable or disable the vtkSliderWidget object defaultly. Here is a post about how to use vtkSliderWidget to control other model, Control The Size Of Model By VtkSliderWidget. But we don’t want the shortcut key to influence the program UI sometimes. So let’s forbid Read more…
Original Status The initial scene looks like the following image. I will rotate cone around point (1, 0, 0) and direction (0, 0, 1). Code #include <vtkActor.h> #include <vtkCleanPolyData.h> #include <vtkDistancePolyDataFilter.h> #include <vtkNamedColors.h> #include <vtkNew.h> #include <vtkPointData.h> #include <vtkPolyDataMapper.h> #include <vtkPolyDataReader.h> #include <vtkProperty.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkRenderer.h> #include Read more…
The article shows how to create a simple vtk render window project and show it in the web browser. We need emscripten tool and the visualization toolkit installed. emscripten : https://emscripten.org/docs/getting_started/downloads.html VTK: https://vtk.org/ Build the VTK source to get JS library before our coding. This example uses C plus plus Read more…