How to change VERTEX into world space?

Question

I am trying to make a 'sine wave' shader and I would like to know how to convert VERTEX from local space to world space. I have tried to do that with this piece of code:

void vertex() {
    world_pos = (WORLD_MATRIX * vec4(VERTEX, 0.0, 1.0)).xy;
    VERTEX.y += sin(TIME * speed + world_pos.x * amp) * amount;
}

However the 'wave' is affected when I move the viewport.

I would like to know what I'm doing wrong and how to fix this.

Thanks in advance.

Comments

Does it act like that when the camera moves while the project is running?

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Yeah, even when the camera moves while the project is running.