Unreadable QR Codes

[trilitech]

Unreadable QR Codes

[mathias-hiron]

Additional feedback from Samuel:

Context

Some Unity apps show a QR code IMAGE that is meant to be DETECTED by an unrelated mobile app (e.g. Web3 Wallet)

Issue

Sometimes the Unity app shows the IMAGE then removes it (a sign of proper DETECTION) in < 2 seconds. The user considers that success. However, sometimes the IMAGE is not removed ever (The user gives up after 15 seconds)

Possible Cause

The QR code IMAGE is not at 100% scale. If this is the cause, perhaps it prevents proper image DETECTION. Further complications of this are that perhaps the API generating the IMAGE does it at SOME scale, then the Unity canvas choose ANOTHER scale, then the Game View is set to yet ANOTHER scale, or in the case of a Unity build to device (ex. standalone or mobile) then there is yet ANOTHER scale introduced.

The QR code DETECTION algorithm (detection and/or communication between mobile and the app and any servers) is not stable. If this is the cause, perhaps the image is detected but some subsequent part of the operation fails or is unstable.
It is certainly possible that EITHER or BOTH 1 and 2 cause the issue. I haven't tested this scientifically with repeated systematic checks.

Workarounds

• At runtime, Ensure the Unity Game View Windows "Scale" slider is set to 100%. I've seen a non-100% value cause problems.
• At runtime, Slowly Unity Game View Windows "Scale" slider between 0 and 100%. I've seen some value (within 95-100%) work. I think this overcompensates for some complication of the scaling.
• I stop and start the mobile wallet. Sometimes I think this works. I haven't tested this scientifically.
• I stop and start the Unity app (stop/start the editor or close/open the build). Sometimes I think this works. I haven't tested this scientifically.

[m-kus]

Reproduced in Unity Player (inside editor) and in MacOS builds