What causes RInterpTo framerate-dependent rotation in Unreal?

RInterpTo and FInterpTo apply an interpolation speed scaled by DeltaTime, so passing a wrong or fixed delta, or a per-frame constant, makes the turn rate vary with frame rate.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix RInterpTo Framerate-Dependent Rotation in Unreal

Q: How do you fix RInterpTo framerate-dependent rotation in Unreal?

Pass the real frame DeltaTime to FMath::RInterpTo(current, target, DeltaTime, InterpSpeed) and tune InterpSpeed, so the rotation converges at the same rate regardless of FPS.

Quick answer: Pass the real frame DeltaTime to FMath::RInterpTo(current, target, DeltaTime, InterpSpeed) and tune InterpSpeed, so the rotation converges at the same rate regardless of FPS.

An actor that rotates to face its target faster on a powerful PC than a weak one is mishandling DeltaTime in RInterpTo. Passing the true delta makes the turn framerate independent. Here is how.

How to fix it

1. Pass the true DeltaTime

Call FMath::RInterpTo(Current, Target, DeltaTime, InterpSpeed) with the frame's actual DeltaTime from Tick, not a hardcoded value, so the speed scaling is correct.

2. Tune InterpSpeed not the delta

Adjust the InterpSpeed parameter to control how snappy the turn feels; it is already framerate independent because the function multiplies by DeltaTime internally.

3. Use RInterpConstantTo for fixed rate

If you need a constant degrees-per-second turn rather than an ease-in, use FMath::RInterpConstantTo, which turns at a fixed rate capped by DeltaTime.

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 Unreal Engine 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.

Ship the fix, watch the signature disappear from the next build. That's how you know it's really gone.