Wikitude

3d Tracking

i am trying to use the Example which was downloaded with the native sdk for 3D tracking ,Created the map put it in the assests,and only changed that line 

 

ClientTracker tracker = _wikitudeSDK.getTrackerManager().create3dClientTracker("file:///android_asset/soha.wtm");


 but only the call back onTrackerFinish is called it does not reconize any thing or excute any other call back what should i do please?