Get the crack tip trajectory

This post focuses on the crack tip tracking method. While I simulate several fatigue models, the crack tip trajectories are hard to track in the model. Previously, I just pick some points and decide the crack length and rate in several images. This useful method is not very effective when I get several video clips in crack place. Several image process tools such as Fiji can deal with the image fast and easy, but I still feel it is hard to realize my goal. So I try to write a simple tool to achieve the object. Since tracking the crack tip uses the technique of image processing, I use the Mathematica for this purpose.

The main function used in Mathematica is the function called “ImageFeatureTrack”. This function will track some feature points in a sequence of images, and return the coordinates of these points in each image. Thus, the idea is not very difficult, we import the video and transfer it into the image sequence, then we specify the tracking points with the coordinates in the image and use “ImageFeatureTrack” function to get the coordinates in each frame. The last step is to turn the image coordinates into the real model coordinates.

The first step is to import the file and to turn into a sequence of images. Additionally, the frame numbers are added to each frame to help inspect the image sequence,


Build VTK 8.1.0 with Qt in Mac

This is the second time I try to build the VTK in Mac. One month ago, I took a lot of time to find how to compile it with CMake and built it successfully, but it is much easier to forget the process. Here I record the entire compiling process.

First step is to download the VTK from the VTK official website. Then, unzip the package to a folder. Here I put it into the folder called “VTK-8.1.0”. By the way, you should also install CMake from the CMake website (Please ensure that the Qt and Xcode are installed in your Mac). Now, create another folder called “VTK_Build”. This is the target folder to save the files generated by CMake. Open CMake and set the “source code” and “binaries” folder: