We can use vtkButtonWidget to create 2D buttons in the render window. The vtkWidgetRepresentation object controls the button’s position and show button pictures. Write our class ButtonCallBack that inherits vtkCommand and use it to listen for vtkCommand::StateChangedEvent, then we can add our button click function in it. Finally, the widget Read more…
Find a local partial region on the surface of the sphere, mark it by red color. Finally, we will compute the normal of the partial region and show it by a green line. The whole scene is just like the following image. Here are a few steps about the process. Read more…
Create a sphere and clip it as the following image. We will pull down the boundary and close the opening to get a new model. How to pull down the boundary of the hemispheres? Step 1. Find all independent edges which are used by only one cell. Step 2. Connect Read more…
The interface vtkObjectBase::UnRegister will reduce the reference count for pointer and delete the pointer if the reference count becomes zero. vtkObjectBase::Delete <= vtkObjectBase::UnRegister <= vtkObjectBase::UnRegisterInternal <= delete ptr vtkSmartPointerBase::~vtkSmartPointerBase { vtkObjectBase* object = this->Object; if(object) { this->Object = nullptr; object->UnRegister(nullptr); } } We can get the reference count and consumer Read more…
There are three adjustment stages of the cone in our test. : rotate the cone and make it bigger. : translate the cone after : translate the cone from the original position. Original Scene Create an initial scene like the following image. The red Read more…
The article shows how to move a model on the surface of the other big one.I planed to move the cube on the surface of a big superquadric in the mouse left press moving event. Let’s build an original scene. Created a superquadric source object in ParaView and saved it Read more…
This post introduces a way to find the biggest plane on the 3D model. We expand the initial cell by comparing its normal with neighbor’s normal. It indicates they are on a plane if the two normals of cells are approximately equal. I use vtkOBBTree to find the min axes 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…
We want to put points on the three-dimensional model sometimes, it’s better if these control points can be moved around the item and project generates a new interpolation line dynamically. VTK provides a tool for us to do it easily. The following content shows two scenarios about point placer, both Read more…