How to create a local coordinate system and show it? We define the local coordinate system has its own x-axis, y-axis, z-axis, and origin. We call the left coordinate system L1 and the right coordinate system L2. Regard L1 as the world coordinate system in VTK, the other one L2 Read more…
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 Extensible Markup Language(XML) can be read by humans and machines, it requires all markups must be paired and case sensitive. The article shows how to write and read the XML file in the Qt environment. Write Data To The Local XML File Create a DOM element by QDomDocument object 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…
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…