nope, you formed and ask your question correctly. There is no need to change words.
VR, AR, MR, Spatial Application and lepciron who wears skirt… they are all the same thing.
You have an Android Application but with different UI/UX designs.
In order to “track, decode, detect” any object in “real” environment, you need two things.
1- Camera buffer (not Unreal’s cameras. I mean HMD’s cameras or RGB sensors. What ever you call)
2- An image processing library which can process that buffer to give a meaning.
Your purpose can be anything. Decoding, tracking, etc.
Library integration is easy. There are lots of sample for that. But if you don’t have camera buffer ? what will you process ? And Quest devices DON’T allow us to access their camera buffer. So, there is nothing to process.
Let’s see your use case.
You have one real life object in real world and one digital twin or equivalent digital data in your scene and they have to be somehow synchronized (movement, informations, etc.). In order to achieve your goal, you have to “detect” that object and this requires camera buffer access. Because you have to process that view to detect your target “real world object”
On the other hand, even if you just try to use USceneCapture2D component to capture your whole MR environment from engine after printing passthrough view to SkySphere and try to process it, you will get only black screen. Because Quest’s passthrough plane is a low level stuff.