How do I detect that localisation has occured? - localization

Question

When utilising a Tango what would I use, callbacks or otherwise to detect when the devise has localised to a previously loaded ADF?
This is mainly for UI purposes in conjunction with Tango UX, telling a user to walk around an environment.

Answer 1

Localization may be detected when your TangoPoseData with a frame of ADF comes back valid.
Look at the Tango Java examples of AreaLearningActivity with this simplified logic:
//tell tango to provide pose for ADF
ArrayList<TangoCoordinateFramePair> framePairs = new ArrayList<TangoCoordinateFramePair>();
framePairs.add(new TangoCoordinateFramePair(
TangoPoseData.COORDINATE_FRAME_AREA_DESCRIPTION,
TangoPoseData.COORDINATE_FRAME_DEVICE));
//register a listener for the frames chosen
mTango.connectListener(framePairs, new OnTangoUpdateListener() {
//listens for updates from tango pose
public void onPoseAvailable(TangoPoseData pose) {
//base frame of ADF provides coordinates relative to the origin of the ADF
if (pose.baseFrame == TangoPoseData.COORDINATE_FRAME_AREA_DESCRIPTION
&& pose.targetFrame == TangoPoseData.COORDINATE_FRAME_DEVICE)
//if the status is valid then localization has succeeded
if(pose.statusCode == TangoPoseData.POSE_VALID){
Log.i(TAG,"Successfully localized with ADF");
}
}
}
Your config must indicate which ADF is of interest:
config.putString(TangoConfig.KEY_STRING_AREADESCRIPTION,adfId);
This process is not easily observed from the code, but I discovered it debugging the AreaLearningActivity example. The Java API would benefit from a higher level of abstraction making the common scenario you requested more obvious and easier to use:
TangoLocalizer.builder().register(myListener).adfId(myAdfId).build();

Answer 2

In Unity3D, you can use pose.status_code inside OnTangoPoseAvailable(TangoPoseData) for checking the checking the status (VALID/INVALID) of pose w.r.t. the coordinate frame pair defined.
For Device Localization you need to set targetFrame as TANGO_COORDINATE_FRAME_DEVICE AND baseFrame as TANGO_COORDINATE_FRAME_AREA_DESCRIPTION
public void OnTangoPoseAvailable(TangoPoseData pose)
{
// Define the frame-pair
if (pose.framePair.baseFrame == TangoEnums.TangoCoordinateFrameType.TANGO_COORDINATE_FRAME_AREA_DESCRIPTION
&& pose.framePair.targetFrame == TangoEnums.TangoCoordinateFrameType.TANGO_COORDINATE_FRAME_DEVICE)
{
// Check if the pose is VALID or INVALID
if (pose.status_code == TangoEnums.TangoPoseStatusType.TANGO_POSE_VALID)
{
////......if pose is VALID
}
else
{
////......if pose is INVALID
}
}
}
You also need to load the ADF using m_tangoApplication.Startup (m_selectedADF); as well.