How to Access Camera Data to Scan QR code in Quest 3?

Yousei-kun · August 5, 2025, 9:27am

Hey, I need a way to access the camera data on Quest to scan a QR code. Is that currently possible? I read about the new Camera API, but it seems to only work with Unity. I had an idea to write something in native code and pass it to C++, but I’m not sure if that would work.

eray_ozr · August 5, 2025, 9:34am

you liked my previous comment about camera access.

As you know, Meta changed their behavior for Quest 3 couple months ago (I think January 2025) When I wrote it there was no way to access them.

Currently, there is no blueprint or C++ way to do it, yet.

Because Epic doesn’t do device specific advance feature implementations and Meta likes Unity more than Unreal. So, you have to wait Meta about integrating it to their custom branch.

https://github.com/Oculus-VR/UnrealEngine

If you need immediately, you have to use JNI. You will first access camera buffer with camera2 API on Java, pass it as jbytearray to C++, convert it to uint8* or char*.

you can look at JNI usage from my plugin.

github.com/Frozen-Archive/FF_RealSense

Source/FF_RealSense/Private/Rs_Android_Context.cpp

main

// Fill out your copyright notice in the Description page of Project Settings.

#include "Rs_Android_Context.h"

// Sets default values
ARs_Android_Context::ARs_Android_Context()
{
 	// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
	PrimaryActorTick.bCanEverTick = true;
}

// Called when the game starts or when spawned.
void ARs_Android_Context::BeginPlay()
{
	Super::BeginPlay();

	//this->RS_Android_Init();
}

// Called when the game ends or when destroyed.

This file has been truncated. show original

Also look at android.xml and build.cs files.

Yousei-kun · August 5, 2025, 9:42am

Thank you so much! That’s exactly what I thought — native code it is, then.

eray_ozr · August 5, 2025, 10:01am

Look at FRunnabeThread. You need it because you won’t want to use game thread to access buffer. After getting buffer to UE, you can use ENQUEU RENDER COMMANDS to create texture. Do that QR processing in FRunnabeThread.

OpenCV doesn’t work on Android in UE5. So, you have to use Nayuki QR. But its Github version can’t build android that can work with UE. There is one marketplace plugin. Use its third party library in your plugin and add decoder to FRunnabeThread. You don’t need texture creation for processing. With this, you won’t do extra buffer extraction.

After process, you can create a texture with same processed buffer.

My plugin have all of these implementations.