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Marker Tracker iOS Tutorial

1. Overview
2. iOS Development
2.1 Create Instants
2.2 Start / Stop Tracker
2.3 Use Tracking Information
2.4 Set Target Marker
2.5 Change Tracking Mode
3. Reference
3.1 API Reference
3.2 Sample


1. Overview

Start developing MAXST ARSDK Marker Tracker on iOS Platform. Refer to Marker Tracker Introduction for detailed information.

By recognizing and tracking the provided markers, you can augment images, 3D objects or videos especially when there are plenty of targets. 8,192 Markers will be provided which were developed by MAXST itself.

Refer to Tracker Coordinate System to better understand 3D coordinate system of Marker Tracker.

Prerequisites
Marker Tracker Introduction
Marker
Tracker Coordinate System

2. iOS Development

Start developing on xCode using Swift. Refer to Requirements & Supports to find out which devices are supported.

ARSDK has to properly integrate on iOS UIViewController. Refer to Life Cycle documents for detail.


2.1 Create Instants

MarkerTrackerViewController.swift

var cameraDevice:MasCameraDevice = MasCameraDevice()
var trackingManager:MasTrackerManager = MasTrackerManager()

2.2 Start / Stop Tracker

To start / stop the tracker after loading the map, refer to the following code.

※To change tracker, destroyTracker() should be called before

MarkerTrackerViewController.swift

@objc func resumeAR() {
        trackingManager.start(.TRACKER_TYPE_MARKER)
        openCamera()
}

@objc func pauseAR() {
        trackingManager.stopTracker()
        cameraDevice.stop()
}

2.3 Use Tracking Information

You can get marker information in 'MasTrackable'. Marker Number is setted function 'getId' in 'MasTrackable'.

※ startTracker() should be called before

MarkerTrackerViewController.swift

func draw(in view: MTKView) {
    ...
    let trackingState:MasTrackingState = trackingManager.updateTrackingState()
    let result:MasTrackingResult = trackingState.getTrackingResult()
    
    let backgroundImage:MasTrackedImage = trackingState.getImage()
    var backgroundProjectionMatrix:matrix_float4x4 = cameraDevice.getBackgroundPlaneProjectionMatrix()
    
    let projectionMatrix:matrix_float4x4 = cameraDevice.getProjectionMatrix()
    
    if let cameraQuad = backgroundCameraQuad {
        cameraQuad.setProjectionMatrix(projectionMatrix: backgroundProjectionMatrix)
        cameraQuad.draw(commandEncoder: commandEncoder, image: backgroundImage)
    }
    
    let trackingCount:Int32 = result.getCount()
    
    var recogMarkerID:String = "Recognized Marker ID : "
    if trackingCount > 0 {
        for i in stride(from: 0, to: trackingCount, by: 1) {
            let trackable:MasTrackable = result.getTrackable(i)
            let poseMatrix:matrix_float4x4 = trackable.getPose()
            
            recogMarkerID = recogMarkerID + trackable.getId() + ", "
            textureCube!.setProjectionMatrix(projectionMatrix: projectionMatrix)
            textureCube!.setPoseMatrix(poseMatrix: poseMatrix)
            textureCube!.setTranslation(x: 0.0, y: 0.0, z: -0.05)
            textureCube!.setScale(x: 1.0, y: 1.0, z: 0.1)
            textureCube!.draw(commandEncoder: commandEncoder)
        }
    }
    ...
}

2.4 Set Target Marker

Once you enter the target marker size (m) and call the addTrackerData, you can track the marker in real scale. Refer to the following code to set a target marker.

MarkerTrackerViewController.swift

func startEngine() {
...
        self.trackingManager.start(.TRACKER_TYPE_MARKER)
        self.trackingManager.setTrackingOption(.ENHANCED_TRACKING)
        self.trackingManager.addTrackerData("{"marker":"set_scale","id":"0", "scale":0.042}");
        self.trackingManager.loadTrackerData();
    }

2.5 Change Tracking Mode

4 Tracking Modes of Marker Tracker:

  • NORMAL_TRACKING
  • ENHANCED_TRACKING
  • JITTER_REDUCTION_ACTIVATION
  • JITTER_REDUCTION_DEACTIVATION
  • NORMAL_TRACKING: Default Setting. Traceable multiple target image.
trackingManager.setTrackingOption(.NORMAL_TRACKING)
  • ENHANCED_TRACKING: This feature tracks the marker intensively that recognizes the first.
trackingManager.setTrackingOption(.ENHANCED_TRACKING)
  • JITTER_REDUCTION_ACTIVATION: Jitter reduction.
trackingManager.setTrackingOption(.JITTER_REDUCTION_ACTIVATION)
  • JITTER_REDUCTION_DEACTIVATION: Disable the jitter reduction option.
trackingManager.setTrackingOption(.JITTER_REDUCTION_DEACTIVATION)

3. References

These are additional references to develop Marker Tracker


3.1 API Reference

Following documents explain classes and functions used to run Marker Tracker.

MaxstAR Class

TrackerManager Class

CameraDevice Class


3.2 Sample

For information regarding sample build and run of Marker Tracker, refer to Sample

MarkerTrackerViewController.swift