Flip Item – Mirror Symmetry

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…

vtkAbstractTransform::DeepCopy May Fail

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…

The Process Of Rotating Object Around Special Point

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…

A Simple WebAssembly Example About VTK

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…

Make Model Always On Top II

We had introduced a way to keep a few special models awalys on the top layer in 3D scene. The relative post: https://www.weiy.city/2020/03/make-model-always-on-top/. But it will fail to shift polygons, lines, and points sometimes, eg. when we are in the WebAssembly environment (wasm) for web page.Let’s use an another method Read more…

Image Color Picker
: Image Color Picker help you to read color information on image.

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