There is a massive module in my project, it computes many data tasks, update UI, and is responsible for interaction style. I want to move the user interaction part to another viewer class, make the old module more lightweight. The structure of the module class looks like the following snippet. Read more…
This is a story about Lv Buwei, prime minister of the Chinese Qin dynasty. Why did he decide to become a government official from a businessman? In 285 BCE, the five states Yan, Qin, Han, Zhao, and Wei formed an alliance and declared a war on the state Qi because Read more…
We will got the following left part’s effect when zoom in and zoom out in VTK render window. How to keep the same display size for the 3D model cube when zoom in or zoom out? VTK changes camera’s status in the interfaces vtkInteractorStyleTrackballCamera::OnMouseWheelForward and vtkInteractorStyleTrackballCamera::OnMouseWheelBackward, the action Dolly moves Read more…
The article shows how to make the original image has a retro style. Two steps need to be done. Change the red color channel of the original image. Change the brightness by a filled circle. The mathematical function used in step1 makes the brighter pixel brighter, darker pixel darker. Read more…
The article introduces how to display an image by OpenCV in CPlusPlus and Python language. The user can exit the whole program when he presses the ESC key. CPP CMakeLists.txt macro(use_cxx11) if (CMAKE_VERSION VERSION_LESS “3.1”) if (CMAKE_CXX_COMPILER_ID STREQUAL “GNU”) set (CMAKE_CXX_FLAGS “${CMAKE_CXX_FLAGS} -std=gnu++11”) endif () else () set (CMAKE_CXX_STANDARD 11) Read more…
The inital scene is like the following image, here are an axes actor and an irregular 3D model. We want to find all points that are on the model and face the plane which has normal (0, 1, 0) and origin (0, -10, 0). My solution spend a lot time, Read more…
I want to find the inner polydata which are surrounded by six planes in the above image. So the intersect point of the three planes that intersect is important. How to find the intersect point of the three planes? We know the mathematical expression for a plane has the following Read more…
The article shows a way to find the bounding shell of the 3D model in its local coordinate system. Let’s create a cone and an axes actor which displays three axes in the world coordinate system. #include <iostream> #include <vtkSmartPointer.h> #include <vtkSphereSource.h> #include <vtkActor.h> #include <vtkConeSource.h> #include <vtkRenderer.h> #include <vtkRenderWindow.h> Read more…
We have to calculate the vector on the special direction firstly. void CalculateVecComponent(PointStruct originVec, PointStruct &axis0, PointStruct &vecOnAxis) { double cosTheta = originVec.Dot( axis0 ); return axis0*cosTheta; } Project point on line Point GetProjectPtOnDir(Point pt, Point dir, Point startPt) { dir.Unit(); Point ptVector = pt – startPt; double cosTheta = Read more…