GSAP scrolltrigger - marker position shifts when header sticky

[moonIMD 0 Likes (Newbie)]

Hi,

 

I am using scrolltrigger to pin a section, but the marker positions starts to shift. It starts to shift when the top header (which contains the logo and nav) becomes position:fixed .

The header starts with no position values set, but as user scrolls down, the header becomes sticky, so  position:fixed is added.

Is it because of this (from position default to position fixed) it causes the markers to shift? Is there a way to fix this issue?

 

Thank you!

[GSAP Helper 122 Likes (Specialist)]

It's pretty tough to troubleshoot without a minimal demo - the issue could be caused by CSS, markup, a third party library, your browser, an external script that's totally unrelated to GSAP, etc. Would you please provide a very simple CodePen or CodeSandbox that demonstrates the issue? 

 

Please don't include your whole project. Just some colored <div> elements and the GSAP code is best (avoid frameworks if possible). See if you can recreate the issue with as few dependancies as possible. If not, incrementally add code bit by bit until it breaks. Usually people solve their own issues during this process! If not, then at least we have a reduced test case which greatly increases your chances of getting a relevant answer.

 

Here's a starter CodePen that loads all the plugins. Just click "fork" at the bottom right and make your minimal demo: 

See the Pen aYYOdN by GreenSock (@GreenSock) on CodePen

 

If you're using something like React/Next/Vue/Nuxt or some other framework, you may find StackBlitz easier to use. We have a series of collections with different templates for you to get started on these different frameworks: React/Next/Vue/Nuxt.

 

Once we see an isolated demo, we'll do our best to jump in and help with your GSAP-specific questions. 

[Rodrigo 5,879 Likes (Superhero)]

Hi,

 

Most likely this has to do with the fact that elements with position fixed are taken out of the document flow, so that basically changes the height of the DOM and moves elements up, which messes up the calculations made by ScrollTrigger. It might be a better idea to have the nav fixed all the time and just add that particular height as a padding top in the first content above the fold.

 

Maybe these examples can help:

See the Pen mdVyPvK by GreenSock (@GreenSock) on CodePen

 

See the Pen qBawMGb by GreenSock (@GreenSock) on CodePen

 

Happy Tweening!