[SOLVED] VR Template sometimes the Triggers work sometimes they do not

So I have some triggers and it seems like I can play through the game and they work, but the next time I try playing through they do not, or they only trigger half the sequence. I am completely lost here. I am using the VR template and the hands do most of the triggering, often without a hitch… however this intermittent triggering is driving me crazy. Any ideas?

I built most of this on 4.16 and now I am using 4.17 so I do not know all that changed… Was this a bad idea to switch?

I’ve long (Several major versions) had an issue that UE4’s on release input event randomly doesn’t always fire. Never happens often enough to reproduce for a bug report. That might be what you are running into. Typically, if it’s important enough for it to release, I do a check every so often to see if the button is still pressed in addition to the on released event.

It is just weird, it seemed like before when I made a trigger it would respond, but now it seems like when I make triggers they either sometimes work or they do not. I have tried on overlap, onhit, etc. My game used to work just fine each trigger working, but now some don’t even trigger, or they trigger half of the sequence and stop. So confusing. So much work.

If it’s happening more than once in a blue moon, you might want to make sure it’s not not a problem with your code. Could setup an empty project and tie a print to the input events and see if it still happens.

What do you mean by “only half the sequence”?

Things to check:

  • Height of the trigger / overlap volumes: Since usually we all develop while sitting and then stand up for a comprehensive test, assuming you have trigger the overlap using a hidden mesh linked to the HMD or something similar, when standing that mesh may be above the trigger volume, so it will never overlap. You can tell I had this a couple of times before… :wink: To check you can place a visible cube inside the trigger volume so that it matches its size, then you can see it in VR. You may find yourself higher than it.

  • Position of the VR body: make sure the hidden mesh / collision volume you use to check the overlap with the triggers is actually aligned with your HMD. For example, it may happen that if you don’t reset your Orientation and Position at the beginning of the play, your “body” is distant from your HMD. Try to visualize it with a visible mesh and see where it is.


I figured it out. I had been doing a lot of Merging of Static Meshes into bigger ones and for some reason (even after setting up very detailed collisions) they all interfered with those triggers. I removed all the Merged actors and replaced them with their originals. It is a lot more work, but holy hell… 3 days of scratching my head being totally confused is now relieved. Phew… at times I felt like I hit a HUGE wall.

That you for your tips and ideas, I think they helped hone in on possibilities.