Mouse click stutters my game


I have a simple game based on overhead template. I have a shooting mechanism written, and I noticed that everytime I press a mouse button, left or right game stutters a bit. Even in standalone mode. At first I thought it was about my projectile mechanism, but if I map Fire to spacebar, shooting is fast.

Clicking mouse buttons without mapping them or having blueprint events for them still makes game stutter even if nothing is mapped to them. And I have disabled mouse actor touch, click and hover events from my Controller.

This is on OSX Maverics 10.9.2 and Unreal Engine 4.1.

Best regards,

Hey Kaali,

I’m haven’t been able to reproduce issue you’re experiencing. Does this happen in every project, or just one? Can you tell us your system specs? Thanks!

I can repeat it by creating a top down blueprint project, get character to move by clicking left mouse button, then click right button fast repeatedly. But I could not reproduce it with flying template even with adding a input mapped to left mouse and adding that to a blueprint as an event.

Exact steps made for new project:

  1. Start Unreal Editor 4.1
  2. Create New Project based on Top Down Blueprint
  3. Disable starter content (not relevant as I have it included in another project which has problem too)
  4. Move with left mouse, quickly tap right when moving to see stutter. Or even left mouse, but right is more interesting as it is not mapped to anything.

My specs are:

  • MacBook Pro, Retina, 15-inch, Early 2013
  • 2.8 Ghz Intel Core i7
  • 16 GB 1600 Mhz DDR3
  • NVidia GeForce GT 650M 1024MB

editor is quite slow on this system, so I usually run in quick settings low mode for comfort. Editor project launcher idles at 20-40% (in Slate OnPaint and PrePass), but that is a completely unrelated issue.

Could you please be more specific on how big performance drop is when you click? I tried Top Down Blueprint template on a couple of Macs and while I did notice a small drop in FPS, it was only 1-2 frames per second less (when running at ~75 FPS). It may need some investigation to make sure it’s justified, but I assume you’re experiencing a bigger FPS drop…

What is your MacBook’s display mode set to? Best for display, or maybe More space? Also, if you haven’t tried this yet - could you try hiding or quitting Unreal Engine Launcher and see if that improves things? Thanks.

I measured numbers inside editor for this test. I get quite stable 70.9 FPS when idling. When I click right mouse button once, it quickly dips to 65ish. And when clicking in fast succession, it drops down to 54-58 FPS. latter numbers are quite approximate as FPS counter updates too quickly.

In a smaller window mode test I get idle FPS of 60 and it drops to 45 when clicking repeatedly.

At moment I’m at second to last option of more space, but I also get dip with “best mode”.

OK, many thanks for these additional details. I’ll investigate this soon.


Thank you for your report. We were not able to investigate this on engine version you reported, but there have been many version changes to UE4 since this question was first posted. With a new version of Engine comes new fixes and it is possible that this issue has changed or may no longer occur. Due to timetable of when this issue was first posted, we are marking this post as resolved for tracking purposes.
If you are still experiencing issue you reported in current engine version, then please respond to this message with additional information and we will investigate as soon as possible. If you are experiencing a similar, but different issue at this time, please submit a new report for it.

Thank you.