ViewTransform stores three vectors in the first three rows and position information in the forth column. We can rotate camera around view up direction [ Azimuth operation ] and horizontal line (sideway) [ Elevation operation ] easily. The relative implementation details in VTK:
The interface vtkTransform::GetOrientation returns Euler angles to describes the orientation of a rigid body.The order of rotation axes in this process is Z, X, Y, but the solving sequence in the interface code is reversed.The implementation details about the interface are here. (from VTK8.2.0) We can write a test program to use Euler angles Read more…
Here is a example about how to use vtkCommand to listen for user’s key press event and change cell scalar to get different cell color.The project is based on VTK9.2 CMakeLists.txt main.cpp Demo：
We can create an timer in vtkRenderWindowInteractor object, then register timerEvent for it to trigger task. Here is simple example about rotating a cone automatically. Result:
My old CPlusPlus project which uses VTK to display 3D scene worked on web page as wasm file. But after upgrading emsdk and compiling the multithreaded version of VTK, I always get the following error on the web page. I test VTK example at vtk/src/Examples/Emscripten/Cxx/Cone from GitHub. But the similar Read more…
We can export a CPlusPlus function in wasm for JS to control the time of invoking vtkRenderWindowInteractor::Start. But after the exported function called, we can’t run the following JS code due to the event loop caused the blockage. Read the code in VTK to find the way to give JS Read more…
Here is a simple example which use vtkMarchingCubes to take iossurface from volume. We use vtkVoxelModeller to create an image data which has scalar data to mark where is inside and outside. Output:
Environment: VTK8.2.0 + Qt 5.12.2. I have tried vtkImageActor, vtkActor2D and vtkButtonWidget to make 2D button in different scenes. After comparing them, I think vtkActor2D is the most convenient and the safest solution. Here is an example using vtkButtonWidget, Use vtkButtonWidget To Create 2D Button. vtkImageActor is a 3D actor, we need Read more…
As we know, vtkTransformFilter can change points’ positions and rewrite data. Then we use vtkTransform object to do linear transform for 3D model. This process is not equal to the multiplication of these two matrices. We can deduce the event in our online tool: 3D Model Editor.Open module linear transform tester. We Read more…