UE5.3 AR Actor Location Not Positioning Correctly (IOS)

I did an A/B test with this fixed 5.4 app and the app built from 5.2 and can not see any difference in the basic performance using the sample HandheldAR project.

It would be great to get this fix into the next point release of 5.4. I know there are plenty of folks out there who are not going to be comfortable modifing the ARKit plugin source code and rebuilding the plugin on their own.

Folks can attempt to download and use my modified version. You need to place it in your project’s Plugins folder. Warning, this doesn’t seem to work for everyone as I can’t properly sign the binary files.
https://www.dropbox.com/scl/fi/gflomuf8qc2kc0donikxo/AppleARKit_UE5.4.zip?rlkey=wq9scp7xexm2prpoyc5kn96lp&st=ggas78n5&dl=0

Oh, one more thing for everyone, it looks like the legacy Xcode workflow is broke in 5.4 as well, so you’ll need to use the Modern Xcode workflow to build dev and shipping apps.

thanks again
-e

3 Likes

TLDR: change the aspect ration of your camera component in the ARpawn
I have been struggling with this as well, with the help of a few comments here I was able to narrow it down to an issue with the aspect ratio on the camera in the ARpawn. If you aren’t comfortable using the language of the old gods and changing the foundations of the known universe a far simpler temporary solution is to simply change the aspect ratio of the camera in the ARpawn. Jeffrey mentioned you can do this in blueprints, which is true, and you can change it in the Details panel under Camera Settings. (Or just search for “aspect ration”) Also the Value is a float so just divide the ratio. I tested this in portrait mode and landscape using the values 2.16 (for landscape) and .46 (for portrait) on an Iphone 15 pro max. And it worked much smoother and was more accurate. I was not using the default AR, I was using marker tracking and facing a similar issue. Thanks everyone for the help!

Hello, the fix for the aspect ratio problem was submitted for 5.4.3 today, and is available in github (same as described earlier in this thread):

https://github.com/EpicGames/UnrealEngine/commit/409df2f80659b1c6a9a67b93dde6425247f7e32c

2 Likes

you are a life saver.

thanks so much
-e

Hi Jeffrey,

I have just tested image tracking and world tracking in 5.4.3 (Launcher) on iOS and your fix did solve the problem! Now actor positioning based on +image tracking is working as it should!

Not in my case, still wobbling way to much, don’t understand what I´m doing wrong here…
Running the latest version on a Mac-mini m2 with uptodate osx and unreal.

Anyone else ?

Are you testing in the Handheld AR project or your own project?

I’d suggest testing initially in the Handheld AR project if you are not doing that.

One thing that we noticed is 5.3 & 5.4 seems to sometimes have AR linetrace issues. So if you are tapping the screen to place your AR object, sometimes the line trace will return the wrong location and your object will not get placed on the ground. This can look like a tracking issue as the object will appear to not “stick to the ground”
One way to see if this is what is happening is to put your device upright on the ground pointed at your CG object. from that angle, you should be able to tell if your CG object is properly on-the-ground.

might be worth testing.

-e