Image 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 Image
2.5 Add / Replace Target Image
2.6 Train Target Image Instantly
2.7 Change Tracking Mode
3. Reference
3.1 API Reference
3.2 Sample
1. Overview
Start developing MAXST ARSDK Image Tracker on iOS Platform. Refer to Image Tracker Introduction for detailed information.
To specify a target for Image Tracker, You should generate 2D Mapfile of the target using Target Manager. Refer to Target Manager and Recommended Conditions for Target Images.
Once 2D Mapfile is created, proceed to 2. iOS Development to continue the tutorial.
Also, refer to Tracker Coordinate System to better understand 3D coordinate system of image tracker.
| Reference |
|---|
| Image Tracker Introduction |
| Target Manager |
| Recommended Conditions for Target Images |
| Tracker Coordinate System |
2. iOS Development
Start developing on xCode using Objective-C. 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
- (void)viewDidLoad
{
...
trackingManager = [[MasTrackerManager alloc] init];
cameraDevice = [[MasCameraDevice alloc] init];
}
2.2 Start / Stop Tracker
To start / stop the tracker after loading the map, refer to the following code.
※ To change the tracker, destroyTracker() should be called before
- (void)resumeAR
{
...
[trackingManager startTracker:TRACKER_TYPE_IMAGE];
}
- (void)pauseAR
{
[trackingManager stopTracker];
...
}
2.3 Use Tracking Information
In the folder where SDK is installed, go to ‘data > SDKSample > Original > ImageTarget' folder, and there is sample target image. Print the image.
If you use the sample code, the following content will be augmented for each image.
- Blocks.jpg: The alpha video is augmented.
- Lego.jpg: The normal video is augmented.
- Glacier.jpg: The cube with the texture is augmented.
To apply tracking results to augmented objects, refer to the following code.
- (void)glkView:(GLKView *)view drawInRect:(CGRect)rect
{
...
MasTrackingState *trackingState = [trackingManager updateTrackingState];
MasTrackingResult *result = [trackingState getTrackingResult];
MasTrackedImage *trackedImage = [trackingState getImage];
[backgroundCameraQuad draw:trackedImage projectionMatrix:[cameraDevice getBackgroundPlaneProjectionMatrix]];
matrix_float4x4 projectionMatrix = [cameraDevice getProjectionMatrix];
int trackingCount = [result getCount];
if(trackingCount > 0)
{
for (int i = 0; i < trackingCount; i++)
{
MasTrackable *trackable = [result getTrackable:i];
if([[trackable getName] isEqual: @"Lego"])
{
...
}
else if([[trackable getName] isEqual: @"Blocks"])
{
...
}
else if([[trackable getName] isEqual: @"Glacier"])
{
[texturedCube setProjectionMatrix:projectionMatrix];
[texturedCube setPoseMatrix:[trackable getPose]];
[texturedCube setTranslation:0.0f y:0.0f z:-0.025f];
[texturedCube setScale:0.15f y:0.15f z:0.05f];
[texturedCube draw];
}
...
}
}
...
}
2.4 Set Target Image
By calling function addTrackerData to register the map file and calling function loadTrackerData, the target image can be tracked. To set a target image, refer to the following code.
※ startTracker() should be called before
- (void)startEngine
{
...
NSString *blocksTrackerMapPath = [[NSBundle mainBundle] pathForResource:@"Blocks" ofType:@"2dmap" inDirectory:@"data/SDKSample"];
NSString *glacierTrackerMapPath = [[NSBundle mainBundle] pathForResource:@"Glacier" ofType:@"2dmap" inDirectory:@"data/SDKSample"];
NSString *legoTrackerMapPath = [[NSBundle mainBundle] pathForResource:@"Lego" ofType:@"2dmap" inDirectory:@"data/SDKSample"];
[trackingManager startTracker:TRACKER_TYPE_IMAGE];
[trackingManager setTrackingOption:NORMAL_TRACKING];
[trackingManager addTrackerData:blocksTrackerMapPath];
[trackingManager addTrackerData:glacierTrackerMapPath];
[trackingManager addTrackerData:legoTrackerMapPath];
[trackingManager loadTrackerData];
}
2.5 Add / Replace Target Image
Create a map file refer to Documentation > Tools > Target Manager
Download the file you created.
Unzip the downloaded file and copy it to the desired path.
2.6 Train Target Image Instantly
If you want to use a raw image file as an image target without an offline training process via Target Manager, enter a JSON object as the first parameter of addTrackerData().
A sample JSON format is like below.
{
"image":"add_image",
"image_path":"ImageTarget/Blocks.png",
"image_width":0.26,
}
The "image":"add_image" pair should be located at first. The value of "image_path" is an image path and the value of "image_width" is a real width (meter unit) of an image target.
A sample code is like below.
[trackingManager addTrackerData:@"{\"image\":\"add_image\",\"image_path\":\"ImageTarget/Blocks.png\",\"image_width\":0.26}"];
The instant training permits only jpg and png formats. An image width as a pixel size should be more than 320 and the best is 640.
※ Instant training of an image takes twice as much time as loading a 2dmap.
※ You must call loadTrackerData () after calling addTrackerData ().
2.7 Change Tracking Mode
5 Tracking Modes of Image Tracker:
- NORMAL_TRACKING
- EXTENDED_TRACKING
- MULTI_TRACKING
- JITTER_REDUCTION_ACTIVATION
- JITTER_REDUCTION_DEACTIVATIO
- NORMAL_TRACKING: Default Setting. Track one target image.
[trackingManager setTrackingOption:NORMAL_TRACKING];
- EXTENDED_TRACKING: Track even at the far distance from the target image.
[trackingManager setTrackingOption:EXTENDED_TRACKING];
- MULTI_TRACKING: Recognize and track up to three target images at the same time.
[trackingManager setTrackingOption:MULTI_TRACKING];
- JITTER_REDUCTION_ACTIVATION: Jitter reduction.
[trackingManager setTrackingOption: JITTER_REDUCTION_DEACTIVATION: Disable the jitter reduction option.
- JITTER_REDUCTION_DEACTIVATION: disable reduce Jitter.
[trackingManager setTrackingOption: JITTER_REDUCTION_DEACTIVATION];
3. References
These are additional references to develop Image Tracker
3.1 API Reference
Following documents explain classes and functions used to run Image Tracker.
3.2 Sample
For information regarding sample build and run of Image Tracker, refer to Sample
