the issue is your source matrix and how it's points/vertices coordinates with your texture. It's kinda weird how you're creating the mesh in the first place. if your end goal is a 15x2 mesh, why not use that dimension initially, instead of weirdly moving around points along the y-axis.

does my photo more resemble what you want? it needs to be rotated, and if you want the slanted lines, that can also be added, but all i did was change the [gen] that creates the vertex array to something that made more sense to me.

Thank you Greg, I extracted this patch from a bigger patch where i'm using particles I modified this test patch to better explain what I'm trying to do

I have the same problem with square texture and matrix here's the new test patch I'm working on

Ok solved here's the patch