Image Tracker
| Related documentations |
|---|
| Target Manager |
| Recommended Conditions for Target Images |
| Tracker Coordinate System |
The Image Tracker recognizes and tracks planar images. It can demonstrate not only 3D objects but also videos, even the transparent one.
Create Instants
Start / Stop Tracker
Use Tracking Information
Set Target Image
Add / Replace Target Image
Train Target Image Instantly
Change Tracking Mode
Create Instants
>ImageTrackerViewController.mm
- (void)viewDidLoad
{
...
trackingManager = [[MasTrackerManager alloc] init];
cameraDevice = [[MasCameraDevice alloc] init];
}
Start / Stop Tracker
To start / stop Tracker after loading the map, refer to the following code.
>ImageTrackerViewController.mm
- (void)resumeAR
{
...
[trackingManager startTracker:TRACKER_TYPE_IMAGE];
}
- (void)pauseAR
{
[trackingManager stopTracker];
...
}
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.
>ImageTrackerViewController.mm
- (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];
}
...
}
}
...
}
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.
>ImageTrackerViewController.mm
- (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];
}
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.
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 ().
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. Traceable one target image.
[trackingManager setTrackingOption:NORMAL_TRACKING];
- EXTENDED_TRACKING: Traceable even at the far distance from the target image.
[trackingManager setTrackingOption:EXTENDED_TRACKING];
- MULTI_TRACKING: Possible to 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];
