Structure Sensor Calibration

Structure Sensor Calibration

Calibrating is essential for aligning the Sensor with the iPad’s camera. Proper calibration improves scan accuracy and ensures optimal depth coverage. To calibrate your scanner correctly, we recommend that you perform these 3 calibration methods described in this document.

Calibration is recommended or needed if you encounter any of the following symptoms:
  1. You don't have a solid red pattern over the body part you aim to scan.
  2. You have a broken pattern with holes or only a few red dots.
  3. The scan box is unstable.
Before starting, make sure that you are using the most recent version of:

a) Structure Sensor Calibrator App. This will be used to perform the Sensor’s calibration.



b) Structure App. This will be used to update the Sensor’s firmware. You can find the firmware’s version by clicking in the ‘’i’’button on the top right corner of the screen when App is running.



1. DEPTH CALIBRATION (not available for Mark 1 sensors)

How to calibrate:

a) Open the Calibrator App without the Sensor connected

b) Connect the Sensor only when prompted by the App. This prevents connection issues.

c) Click on the question mark (?) in the top left corner.



d) Click on ‘‘Perform Refinement’’, swipe to the left twice, then press on ‘Start Refinement’.





e) Hold your iPad about 3 to 4 feet away from a flat mat wall with no decoration. Move closer or farther until a solid red pattern is seen. If a solid pattern cannot be acquired, save and re-run the calibration.



f) Hold still until you see ‘Refinement complete’. This will take a moment.



g) Click on "Save refinement" to finish. Depth calibration is complete.



2. STEREO CALIBRATION

This calibration ensures that images from both the iPad’s camera and the infrared one integrated in the Structure Sensor are perfectly aligned, one over the other. The calibration must be done if the infrared looks unaligned.

How to calibrate:

a) Print the Indoor Calibration target and stick it on a wall. It can be printed in color or in black and white.


b) Open Calibrator App.
c) Click on the Standard Calibration.



d) Click on Begin Calibration.



e) Enable ‘’Indoor Mode’’ in the bottom right.



f) Point the scanner towards the target on the wall until you see two images of the target on your screen. Disregard the instruction concerning the surroundings and click on ’’Got it’’.
g) The scanner will take a couple of pictures with blue dots all over them.



h) Wait until the calibration is completed. When finished, you will receive the message showing there is one last step to follow. You can select SKIP or Start Tutorial.

i) Point your scanner towards a scene with right angles, like the corner of a table. The 2 images will then need to be adjusted so they align, by moving your finger on the screen from left to right or vice versa. This should result in 2 aligned images.






j) Once satisfactory, you can click on ‘‘Save Calibration’’



k) Click on ‘’Back to Welcome Screen’’.



l) Close the App.

3. GRAVITY CALIBRATION


This calibration is done within the 3DsizeMe app, it is related to the iPad and has nothing to do with the Structure Sensor. It can be found in the settings menu under the SCAN section. Pressing the ‘‘Calibrate’’ button will begin the process. TheiPad must be aligned vertically for this calibration to work.

Calibration may be necessary in the case of:
  1. unstable scanning box that tends to flip or;
  2. when the box seems misaligned with the horizon.
How to calibrate:

a) Find a leveled surface


b) Lay down the iPad on its side and align it straight up using a level



c) Click on calibrate



4. Complementary information

If a message appears mentioning that the firmware needs to be updated, please use the Structure app available on the App Store. Follow the instructions. This procedure may take 3 to 5 minutes.

For more information regarding the Structure Sensor and its calibration, please refer to this video.

    Still need help?

    Contact us at support@techmed3d.com!

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