Only able to detect and track up to 4 images at a time with ARKit 3.0

Question

Using the code below I\'m only able to detect and track up to 4 images at any one time when using ARKit.

ARImageTrackingConfiguration *configuration = [ARIma         


        

Answer 1

Updated: February 08, 2020.

At the moment in ARKit 3.0 and ARKit 2.0 you can simultaneously track up to 4 images. Not more than four.

Even though ARKit 3.0 official documentation says that .maximumNumberOfTrackedImages instance property could be equals to 100, this hundred of images is just a total number of tracked images in a session. Apple software engineers limited image tracking feature to four images at a time. This makes sense because tracking more than four images at a time is very CPU- and GPU-expensive.

Also, you can read about it here.

- (void)viewWillAppear:(BOOL)animated {

    [super viewWillAppear:animated];

    ARWorldTrackingConfiguration *config = [ARWorldTrackingConfiguration new];
    config.detectionImages = [ARReferenceImage referenceImagesInGroupNamed:@"Resources" bundle:nil];

    config.maximumNumberOfTrackedImages = 100;       // in ARKit 3.0
    // config.maximumNumberOfTrackedImages = 25;     // in ARKit 2.0

    [self.sceneView.session runWithConfiguration:config];
}

Answer 2

Found the official answer in a comment made to ARImageTrackingConfiguration:

@discussion Image tracking provides 6 degrees of freedom tracking of known images. Four images may be tracked simultaneously.

EDIT: Found in ARConfiguration.h, line 336