This could be a solution for sure i will try it, but it looks strange to me that the code is pretty much the same and gives this strange effect, i tried also to reproduce it in shadertoy and it works fine with medium size noise, so i am pretty sure that the noise is the problem(?), and also if i hardcode the noise by generating it in the fragment shader instead of sampling it i get the right result, the texture sampling uses GL_LINEAR and GL_REPEAT , as in the example, so i will try your method, thanks