[Mac] Mouse sensitivity/acceleration regression across Viewport, PIE, and Event Graph panning since UE 5.8
What Type of Bug are you experiencing?
Editor
Steps to Reproduce
Launch UE 5.8 Editor on macOS
Open any project, open a level in the Level Editor
In the viewport, right-click and drag to look around - note sensitivity/acceleration feel
Go to Edit → Editor Preferences → Level Editor → Viewports → Mouse Sensitivity, lower the value, confirm viewport look/aim and actor drag now feel corrected
Click Play (PIE) and use mouse look - observe sensitivity is still elevated/accelerated despite the setting change in step 4
Open any Blueprint, go to the Event Graph, and pan the graph with held right click, observe panning is also elevated/accelerated and unaffected by the Viewports Mouse Sensitivity setting
Expected Result
Mouse sensitivity should not be higher than experience on other platforms like Win64, requiring platform specific Mouse delta modifiers for in-game look aim speeds to feel similar.
Observed Result
Mouse sensitivity has greatly increased between the 5.7 and 5.8 editors on the MacOS platform, where side by side editors can be observed inconsistant.
A commit to the Unreal Engine (4df54386988ae493a92f283532d31fadf2cbfdcc)
focussed on [Mac] high-precision mouse movement implementation with the GCMouse-based
I may not be a os level developer, but I did modify this change, and decreased the mouse delta raw values by 4x to restore mouse sensitivity expectations.
This fix requires Unreal Engine Source Build.
In method FAppleMouseController::DispatchMovementUpdates()
At line 160:
FVector2D RawMovementDelta(CurrentMovementState.MouseDeltaX.exchange(0.0f), CurrentMovementState.MouseDeltaY.exchange(0.0f));
RawMovementDelta *= 0.25f; //Reduce sensitivity by 4x
Mouse hyper sensitivity for MacOS still present in 5.8.3 release.
Can anyone else confirm the Mouse input feels 4x higher in ViewPort, PIE, and EventGraph Panning?
Or I’m having an isolated incident with my choice of LogiTech mice.
Current Specs
MacOS27
Macbook Pro M4 Max
External Widescreen Dell Monitor
LogiTech MX Master 4
Same here. My mouse was working perfectly fine in 5.7, but since 5.8 it’s almost unusable due to the extreme high sensitivity, especially when panning around in EventGraph. Tried both a Logitech mouse and an Apple Magic Mouse, and this one is even worse. This behavior wasn’t present in previous UE versions.
Specs
UE 5.8.3
macOS 26.7
Mac Studio M1 Max
Apple Studio Display
I’ve posted a Branch after forking the 5.8.3-release to help any MacOS users out there.
This solves two issues:
Lower in editor Mouse sensitivity back to 5.7 expectations
Fix failing to build Unreal Editor from source when it tries to finalize the .app
Same. I can’t use 5.8 because of this.
Turning off “Use High Precision Mouse Movement” in Editor Preferences fixes the issue in the graphs but not in the viewport.
UE5.8.3
Macbook Pro M5 Max
macOS Tahoe 26.6.2
Dell S2725DC & Dell S2722QC
Logitech M550
After some additional digging to understand the AppleMouseController and the edits that went in with this high-precision commit, I spotted that a Mac CVar was created in the MacApplication.
This means the easiest solve for restoring mouse sensitivity on MacOS (including Launcher version), is a small edit to the projects ini