VR Selfie Stick Causing HMD Camera Jitter

Development Programming & Scripting Blueprint
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1

Hi there -

Hoping to figure out what’s wrong with my setup in unreal 5.4.

I’m making a VR selfie stick with a CineCam that is not locked to hmd. (This is a separate blueprint from the vr pawn) The selfie stick has a CineCaptureComponent2D which sends the texture to the desktop screen, while the player is in VR.

This causes my player cam to be really shaky. I think the hmd is trying to pick up the CineCam as well but i have no references to it and can’t seem to find a way to make the hmd ignore the cine camera completely.

Here is a link to my selfie stick setup and the vr pawn setup: Imgur: The magic of the Internet

The whole thing is really confusing and I’m really not sure what is happening. I’m using a quest pro if that helps.

2

Do small test:

  • copy whole camera setup to separate pawn
  • when doing selfie, instead of using stick, spawn that pawn and do exactly same there

You should know it culprit is stick or camera.

Shaking usually happens when there are two updates fighting over camera location.

3

@Nawrot I just tested this.

I created a new Pawn with just a CineCam and CineCaptureComponent2D. I also had set it to Player 1 rather than 0 just in case.

I am unable to spawn this pawn when doing a selfie as the intention is for it to always be active, sort of serving as a selfie camera and a persistent spectator camera.

Unfortunately the jittering still persists.

4

So pawn and your VR setup both have jittering.

Try some lag on camera arm. This may show if jittering is caused by concurrent updates to camera location, or something else. If changing lag limits jittering, there is something else trying to update camera besides selfie stick.

5

@Nawrot so i’ve tried adding a bit of lag to the camera arm and it didn’t solve the jittering. It made general movement smooth but not the shaking effect.

is there a way to prevent the selfie camera from being picked up by the hmd?

here are two videos displaying the issue:

Selfie Stick Perspective - Only shakes when grabbed: https://youtu.be/4BL0Z5srh7o

HMD Perspective - Always Shakes: https://youtu.be/25slmNYxPu8

6

This looks like it is caused by HMD setup, not arm+camera stick. I am guessing here, but it looks like it tries to fix camera, records some frames, then tries again to fix it in another location.

But camera should be independent from HMD. Try placing that camera relative to player position, not relative to hand (just for testing). You need narrow down what exactly is causing jittering.

And you can do line trace or capsule trace, with some longer time to keep lines drawn.
Or there is whole thing called “Visual Logger” that helps debugging what and where happened.