AR "Add Runtime Candidate Image" won't work

I have been trying to add an image to a SessionConfig Candidate Images list using the Add Runtime Image Candidate node in the editor and packaging for Android and I haven’t been able to make it work in 4.22.1, 4.21.1 or ARCore’s branch of 4.21.
I have tried different ways of referencing the SessionConfig, using JPEGs and PNGs in color and in grayscale and no matter what I do the node always returns null.
Do I need something special to make it work? Can anyone replicate?

Hi, I’ve got the same issue. Working with ARCore modified 4.21 engine.
Did you find a solution yet?

I have the same issue

Same isssue here, can anyone help?


how are you using jpes or pngs?
Are you converting to a Texture 2D and then ARCandidate Image at runtime?

For example in BPs:
“Import File as Texture 2D” -> “Add Runtime Candidate Image” -> Add Candidate Image

Yes, that is exactly my setup.
“Import File as Texture 2D” - return value into “Add Runtime Candidate Image”.

I could see the image after importing, converting it to a brush and making it an image widget.

Haven’t tried to see if it’s fixed in 4.23 or 4.24p yet.

Hey, F.Oliva, i met the some problems with you guys, are you finally figure it out?

I wasn’t able to get it working, but I didn’t try any of the new engine versions.

What version are you using? Is the texture being imported correctly?

Im using 4.21 ARCore soure version, Actually i tried two ways:

  1. I create a function called to add candidateImage with c++, with this way, i can get the the Friendly name and use this texture from ARCandidateImage as brush to display it, after i stop the project, i can actually find the “new arcandidateImage” inside ARSessionConifg, but those new ARCandidateImage from engine transient.

  2. The second way i tried is l use the native node “Add Runtime ARCandidateImage” to it, even this Texture is already a usasset, but after this node, i use node “isvalid” to test, its not valid …
    with second way i tried 4.21 source engine and 4.24 launch version, its same.

Well I’m a few years late but I got a warning on phone that the texture format must be PF_B8
R8G8A8 or PF_R8 (Don’t remember exact names tbh) for it to work.
that can be easily be fixed by setting texture compression settings to UserInterface2D type.
but AddRuntimeCandidateImage still gave me warnings:

Warning: Reloading inlined bulk data directly from disk, this is detrimental to loading performance. Filename: ‘/CardTextures/snake.uexp’.
D/UE4 : LogGoogleARCore: Warning: Failed to add runtime candidate image: No valid session!

And returned nothing. so still no avail. I’ll update you guys if I learn something new on this.