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…
A JSON file stores data objects in JavaScript Object Notation(JSON) format. It’s lightweight and readable, the developer uses it to transmit simple data. The article shows how to create and read the JSON file in the Qt environment. I planed to save two books’ information to a simple JSON file 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…
I want to save a little data into a local file that we read it. It is best done conveniently through C Plus Plus. The following example shows the entire logic. #include <iostream> #include <vector> #include <fstream> using namespace std; std::string filePath = “txt”; void WriteData() { double origin[3] = 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…
The article shows how to create a simple vtk render window project. We need cmake and the visualization toolkit installed. This example uses C plus plus programming language to create and show a cone in the 3D world. CMakeLists.txt cmake_minimum_required(VERSION 2.8) project(mytest) find_package( VTK REQUIRED ) include( ${VTK_USE_FILE} ) add_executable(${PROJECT_NAME} Read more…
Independent Thread We want to run a single task in an independent thread in a convenient way in some scenarios. It is common in data process and UI interaction event, for example, we want to use QMovie object to play a gif to indicate our software is analyzing test data, Read more…
The filter vtkWarpScalar can help us to move the point along point normal by the scalar amount times the scale factor. We can change the size of the original model with it as long as there are normals in data. The following example has two renderers, the left renderer shows Read more…
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