Strange (and serious) behavior of "get hit result under cursor by channel" on mac

Macbook M3 max
Unreal 5.4.4

  • new project, empty, scaleable
  • clean character blueprint
  • node connected to tick only

Hello, When using get hit result under cursor by channel node this behavior happens:

If i connect the out hit location to a set vector, that vector values will change while i move the mouse around, as expected. BUT:

If i press the mouse LMB \RMB, the value under the cursor there will be “saved” and if i press again - that value will be set to the vector.

Is that behavior intentional ? why is it evenz responds to a button press while only tick is connected and no input code exists

I added a video to help understand the problem.
As shown, after first button press the vector will set these values everytime i press again. I move the mouse around there btw, you just cant see that in game.

Unless im mistaken, the mouse button should not do anything, because there is no call for a button press its only tick connected to that node.

Hope someone can help with that

Hey there @Userofunreal! Welcome to the community! Could it be related to the mouse locking functionality? I can’t seem to replicate this on Windows, so I’m thinking the mouse capture function is probably causing it. Let’s devise a test.

Give this setup a try:

Then once you’ve locked in, hold alt and click around, does the issue still occur?

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Thank you @SupportiveEntity for your help.
I copied your code, and while holding alt (option key) the issue does not happen. But, only as long as i hold it down

May you please help me to understand what is this mouse lock and why is it present in such way in unreal ? (is it something epic should solve in an update?)

So my hypothesis is that the differences in how the OS (or how unreal handles) the locking of the mouse to the window. I was taking a look into the source to identify if there’s a clue to the disparity but have been unable to find it.

Does the Convert Mouse Location to World Space node do the same? (would need further processing for your use case but this might help determine if it can be worked around)
image

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(post deleted by author)

Thank you for helping me sir
(I was just asking before how to replicate test, this is why i deleted it. )

Yes, the same problem happen with this node as well. (holding alt will disable the issue as long as i press it like before)

Ahhh unfortunately in this case, I’m not sure of a workaround. Does adjusting these settings change how the error presents? It’s unlikely but if it changes at all, we may have a foothold to work with.

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Disable all capture and lock will remove the issue but i guess its gonna make problems in other places later?

What is mouse lock and capture?

Yes that causes more than a couple of issues, especially when it comes to multi-monitor setups or playing in windowed modes. Though it does tell me that we were correct in assuming that the locking is what’s causing it. Though if that was the only setting that changed the behavior, we won’t be able to use it as a workaround.

Mouse locking is meant to keep the mouse inside the client as well as keeping it centered on a location and translating the movements to the application.

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thank you for all the help. i appreciate it

How i should contact epic about this? seems like an unreal - mac problem

Here’s the bug report page:

https://www.unrealengine.com/en-US/support/report-a-bug