UI ScrollRect inertia does not work between 35-50%

Questions & Answers
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1

I’ve spent the last few hours optimising an image search results screen within my companies app and have encountered bug with Unity’s ScrollRect component.

Steps to reproduce:

  • Create a vertical scroll view with a content area 6000 or taller
  • Turn on inertia
  • Start the app/game
  • Scroll to 35% of the content at which point inertia stops working
  • Once you reach 50% inertia starts working correctly again

The greater the height of the content panel and/or larger deceleration rate the more noticeable it is.

This happens when running within the editor and on my Android phone (haven’t had a chance to test on iOS yet).

I’m using Unity 5.4 but this was also happening with a previous 5.3 build.

5

Same issue is observed.

Here’s a pastebin of a script i wrote to manually use scrollbars.

Note that the issue is not observed when scrollbars are not assigned to scrollrect.
This is a Script to workaround the issue temporarily, by not assigning the scrollbar to the scroll rect, But to update the scrollbar functionality manually.

2

i think there’s a bug with the scrollbars. for us we removed the scrollbars and the scrolling is smooth again.

6

Issue still exists in version 2017.2.0f3. Taking scroll bar off works.

4

Just tried in 5.5 and it still seems broken.

3

Has anyone found a workaround for this that doesn’t involve getting rid of the scrollbar? This does indeed solve the problem but I need scrollbars in my game. I haven’t been able to update Unity since 5.3.5 because of this bug being introduced and I can’t figure out a way to solve it.

7

Same for me, still exists in 2018.1.0f2. I wrote a recycle cell script with about 5000 elements. From 0 to 1100 the inertia does not work.

8

I’m still running into this issue in Unity 2022.3.7f1. The height and % scrolled doesn’t seem to be as specific at the OP implies (I’m seeing it not be an issue with some heights over 6000, and seeing the issue at different scroll %'s than the 35-50 in the original post). A little ridiculous that this 7 year old bug still exists.