I'm actually trying to apply my scrolltrigger parallax effect only when my element in in viewport but I can't make it works ... Has someone already went through something similar ? Can someone help me wake it works ?

Here's the demo : Codepen

if (ScrollTrigger.isInViewport(".block-1")) {
  gsap.to(".block-1", {
    yPercent: 100,
    ease: "none",
    scrollTrigger: {
      trigger: ".block-1",
      start: "top bottom",
      end: "bottom top",
      scrub: true,
      markers: true,
      id: 'block-1'
    }, 
  });
}

Thanks in advance.

Valord