Although your Tango device was calibrated at the factory, you can improve performance and reduce drift during motion tracking by performing an additional calibration using the Tango Calibration Application (app). You perform the calibration by walking in a small loop and moving the tablet in a specific motion (described below) while you record your surroundings.
Downloading and installing the app
To download the Calibration APK, click here:
After you download the APK, you can install the app using adb.
Before you start
To perform a successful calibration, choose an area that is well-lit and contains numerous objects with colors and textures that are distinct from adjacent objects.
Calibrating your tablet
Launch the app.
In the Tango Calibration message box, tap Next.
View the animation in the Calibration Instructions message box.
The animation shows you how you should move the tablet when you perform the calibration.
Stand in the spot where you will start your walk and point the tablet ahead of you, with the screen facing you.
In the Calibration Instructions message box, tap Start Calibration.
The Data capture underway message box appears:
Hold still for a few seconds, and then begin walking while you perform the required motion with the tablet.
Walk in a small loop, and end in the spot where you began. As you move, the camera in the tablet records what it sees and displays it on the screen. While you are walking, move the tablet from side to side in a figure-eight pattern. Also, tilt the tablet forward and backward (pitch), swivel it left and right (yaw), and pivot it from side-to-side as if you are "walking" it on its bottom corners (roll) in continuous and simultaneous movements. Make your pace and arm movements slow and steady, and complete your loop in 15 to 20 seconds.
When the tablet has captured enough data to complete the calibration, the Data capture done message box appears:
The Calibrating message box appears and lets you know that the view you recorded is being processed.
After processing finishes, a message appears telling you whether the calibration succeeded or failed.
If the calibration succeeded, the Calibration complete message box appears:
To keep the previous calibration, tap KEEP PREVIOUS. The new calibration is discarded, and the app exits.
To use the new calibration, tap USE NEW. The new calibration is saved automatically, and the app exits.
If the calibration failed, the Processing Failed message box appears and tells you possible reasons for the failure.
Here is more detail about why a calibration might fail:
There was not enough light: Increase the light in the area or move to an area with better lighting.
There were not enough contrasting textures: Move to an area that has more contrast.
Movement was too fast: Quick movement can cause the camera image to blur. Try moving at a slower pace.
The tablet motion was not sufficient: Increase the degree of pitch, yaw, and roll as you walk, and keep the tablet moving continuously and simultaneously throughout the recording.
If you want to start the calibration process over from the beginning, tap REPEAT CALIBRATION.
If you want to cancel the calibration and exit the app, tap CANCEL.
Restoring the default calibration
In the message box that appears when you start the app, there is a RESTORE DEFAULTS option:
If you have issues that are not resolved by performing a new calibration, you can choose this option before recalibrating. It restores the tablet to its original factory calibration setting.
To restore defaults
- In the opening screen message box, tap RESTORE DEFAULTS.
- In the Restore defaults message box, tap RESTORE.