How to crop the playing field in Unity 2d?

Question

Unity

Hi, thanks in advance for the helpful replies. The crux of the matter, I fixed the gif-image, tell me an article, video or something else to implement what was planned on the gif. In fact, there is a ball that moves vertically and horizontally by pressing the button W/S-up, down A/D-left, right. You need to add a trace after it and when closing, delete the selected part.

Answer 1

Judging by the gifs, the field is discrete, 10x10. Therefore, you can make it out of 100 squares and delete them.
Another option is to create and stretch white rectangles.
Also, the best thing is to edit the vertices of the mesh.