Tool
Create Lock By Blender
The post shows how to use blender to create a lock model simply. youtube bilibili The STL file in the video can be downloaded by the link:
Web
Make Your WordPress Website Has The Ability To Check Network Connection.
The post introduce a way to make your wordpress website has the ability to check network connection. Install the plugin Insert Headers and Footers for wordpress. Add the following code in header part. <script> if (“serviceWorker” in navigator) { navigator.serviceWorker.register(“/serviceworker.js”) .then(function(registration) { console.log(“Service Worker registered with scope:”, registration.scope); }).catch(function(err) { Read more…
Math
Use Singular Value Decomposition In VTK
Affine transformation can be decomposed to translation, rotation, and scale. As we know, the transformation can be represented by matrix. Related post: https://www.weiy.city/2021/11/the-releationship-between-local-transform-and-pose-transform/ It can be computed by translate matrix and rotate & scale matrix. Example: I try to do decomposition for a matrix. Read more…
Math
Transformed Normal May Not Be Perpendicular To The Surface
We know the matrix shearing object along a particular axis looks like: The shear transform can help us to approve that when a normal vector is transformed using the same matrix that transforms the points on an object, the resulting vector may not be perpendicular to the surface Read more…
Algorithm
The Matrix Of Rotate Around The Axis In 3d
As with 2D transforms, any 3D transformation matrix can be decomposed using SVD into a rotation, scale, and another rotation. Any symmetric 3D matrix has an eigenvalue decomposition into rotation, scale, and inverse-rotation. Finally, a 3D rotation can be decomposed into a product of 3D shear matrices. Rotate about z-axis: Read more…
Math
The Releationship Between Local Transform And Pose Transform
Here are three vectors (1, 0, 1), (-1, 0, 1) and (0, -1, 0) in the 3D world space. Define a position pos(1, 1, 0). These vector and position forms a new coordinate system A. The inverse result is status B. The original world coordinate system can be changed to Read more…
VTK
VTK – Create Cube From Four Points
Here are four points in 3D space, we will take them and generate another four points to draw a cube. Construct triangles to form cells for the mesh, the normal of every cell is toward inside. Here are all details about the generation. Update on 2023.10.17: The cells’ normals generated Read more…
Algorithm
3D – Rotate Axis System To The Special Orientation
The post is based on https://www.weiy.city/2021/11/vtk-rotate-vector-to-special-direction/. We will rotate the three axes of the world coordinate system to particular directions. #include <iostream> #include <vtkSmartPointer.h> #include <vtkTransform.h> #include <vtkActor.h> #include <vtkConeSource.h> #include <vtkRenderer.h> #include <vtkRenderWindow.h> #include <vtkPolyDataMapper.h> #include <vtkRenderWindowInteractor.h> #include <vtkAxesActor.h> #include “../point.hpp” using namespace std; double AngleBeteewnTwoVector( Point vec0, Point Read more…
Python
Create Service : Make Images From PDF 2
We have to create zip file from output folder. After that users can download the result. Install zipfile module for python. pip install zipfile36 Use it in our python script to generate zip file. import sys, fitz # import the bindings if sys.version_info >= (3, 6): import zipfile else: import Read more…