public void setVertex1(final int x, final int y, final int z) {
        if (this.x1 != null && this.y1 != null && this.z1 != null && this.x1 == x && this.y1 == y && this.z1 == z) return;

        this.x1 = x;
        this.y1 = y;
        this.z1 = z;
        this.refresh();
    }