StephenWei

One trick to figure out how to choose an SLR lens

你永远是镜头焦点…… You are always the focus of the lens 初学者第一次购买相机都会选择套机。 导购员会说：一支变焦镜头一镜走天下， 适合在不同场合中使用，基本满足日常所需。 Beginners will choose a set of cameras for the first time. The shopping guide will say: a zoom lens and a mirror go to the world, Suitable for use in different occasions, basically meet daily needs. 通常来说，使用变焦镜头想要有大光圈，就得付出非常昂贵代价，而定焦头用「白菜价钱」就可以轻易买到「烧鹅味道」的大光圈镜头。 光圈越大，搜集的光线比小光圈的变焦镜头多，可以轻易制造浅景深的效果，在晚上或室内弱光环境下不用调高感光度（ISO）就可以拍到所想的照片。加上定焦镜头的构造纯粹，素质往往都会比变焦镜头高，而且价钱相宜，物美价廉谁能不爱。 Read more…

By StephenWei, ago

Flip Item – Mirror Symmetry

As we know, we can create a linear transform to change model to the special orientation and position. Refer to The Releationship Between Local Transform And Pose Transform. Let’s define orientation and position by three axis and point. , , and origin = . The matrix for the linear transform Read more…

By StephenWei, ago

New Web App – To Do Tasks

We had created a new web app, to do tasks, at https://www.weiy.city/functions/to-do-list/ . You can add tasks and enjoy the working time every day. If you want to access the app easily, just do the steps in the following video to the app icon on the desktop.

By StephenWei, ago

vtkAbstractTransform::DeepCopy May Fail

Here is a example that vtkTransform object failed to deep copy the other one. #include <iostream> #include <vtkSmartPointer.h> #include <vtkRenderer.h> #include <vtkRenderWindow.h> #include <vtkTransform.h> #define vtkSPtr vtkSmartPointer #define vtkSPtrNew(Var, Type) vtkSPtr<Type> Var = vtkSPtr<Type>::New(); int main() { setbuf( stdout, nullptr ); vtkSPtrNew( trans, vtkTransform ); auto matrix = trans->GetMatrix(); matrix->SetElement( Read more…

By StephenWei, ago

Image Compressor

Here is a web app which can help you to compress your image.It’s simple to use it, just upload your image, click on the compress button and download the new picture. You can change the compressing rate for the original image by dragging the slider bar. Page: https://www.weiy.city/functions/image-compressor/ Demo video Read more…

By StephenWei, ago

The Process Of Rotating Object Around Special Point

Original Status The initial scene looks like the following image. I will rotate cone around point (1, 0, 0) and direction (0, 0, 1). Code #include <vtkActor.h> #include <vtkCleanPolyData.h> #include <vtkDistancePolyDataFilter.h> #include <vtkNamedColors.h> #include <vtkNew.h> #include <vtkPointData.h> #include <vtkPolyDataMapper.h> #include <vtkPolyDataReader.h> #include <vtkProperty.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkRenderer.h> #include Read more…

By StephenWei, ago

A Simple WebAssembly Example About VTK

The article shows how to create a simple vtk render window project and show it in the web browser. We need emscripten tool and the visualization toolkit installed. emscripten : https://emscripten.org/docs/getting_started/downloads.html VTK: https://vtk.org/ Build the VTK source to get JS library before our coding. This example uses C plus plus Read more…

By StephenWei, ago

Tex To PDF
 : convert the Latex file which suffix is tex to a PDF file

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