How to Fix an Easing Function Not Ending at One in Unity

A UI element that settles slightly off its target, or snaps at the end of a tween, has an easing curve that does not start and end at the right values. Fixing the endpoints removes the pop. Here is how.

How to fix it

1. Check the endpoints

Evaluate your easing function at t=0 and t=1; they must return exactly 0 and 1. A function like a miswritten ease-out that returns 0.98 at t=1 leaves the value short.

2. Clamp t before evaluating

Compute t = Mathf.Clamp01(elapsed / duration) so t never exceeds 1. Feeding t>1 into a polynomial ease sends the value past the target.

3. Snap to the end on completion

On the final frame set the value to the exact target rather than relying on the eased t, so float error in the last step never leaves a visible offset.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.