The vtkCamera object has a front clipping plane and back clipping plane. Users can only see the middle part between the clipping planes. So we can change the clipping plane's position, clipping range, to get a different 3D scene. The relevant variable in VTK is double vtkCamera: ClippingRange[2];. When we Read more…
The algorithm class vtkPolyDataNormals can be used to calculate normals of points and cells in polydata. The following example shows how to use it. Cube Create a cube in which every cell is a single square. All information can be found in polydata, we use vtkPolyDataNormals to handle it and Read more…
Sometimes the 3D model and 2D object will be overlapped as the above scene. I want to move the text to the top for avoiding overlap situation. My solution has these steps: 1. Calculate the bounding box of the sphere and convert it to a rectangle which wraps the image Read more…
We can put model in VTK display coordinate system. The following example is based on a previous article: Show Special Character In VTK . I add a line which start from (0,0) to left bottom corner of red string, the line is represented as 2D model. int *size = renderer->GetSize(); Read more…
We can use vtkTextActor to show string which contains special character. I use encoding value to represent math symbol and store it in QString object in the following example. #include <vtkActor.h> #include <vtkPolyData.h> #include <vtkRenderer.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkSmartPointer.h> #include <vtkTextActor.h> #include <vtkSphereSource.h> #include <vtkPlaneSource.h> #include <vtkPolyDataMapper.h> #include Read more…
After upgrade vtk from 7.1.0 to 8.2.0, the old project shows a warning window about VTKWidget. The newest vtk-qt program suggest me not to use old QVTKWidget anymore, so I rewrite my qt UI file I have qt UI file as the following code snippet, a few widgets are put Read more…
Draw The Plane Manually We can create a big plane if we know its origin and normal. The algorithm class vtkPlaneSource is a solution for it, but the generated plane is too small, it’s hard to create a big plane based on vtkPlaneSource, so I wrote a function for the Read more…
They are many different cells in VTK, they can be divided into two kinds, linear cells, and non-linear cells. The following images are from VTKUsersGuide. Linear Cells Non-Linear Cells Although vtkUnstructuredGrid and vtkPolyData are similar, there are substantial differences. vtkPolyData can only represent cells of topological dimension 2 or less Read more…
Here is relevant introduction about vtkImageData from VTKUsersGuide. A vtkImageData dataset is defined by data dimensions, interpoint spacing, and the origin (i.e., lower-left corner) of the dataset. If the dimension of the dataset is two, then we call the vtkImageData dataset an image, and it is composed of vtkPixel cell Read more…