Hi Luca! Can it be the case that you're using the Wikitude SDK 3.3.0? This particular version of our SDK had problems generating the image on iPhones. Please download the Wikitude SDK 3.3.1 which fixes this issue.
Please respond in this thread if your still have problems after updaing to 3.3.1.
about 5 years ago
I'm using this code, token from example project, to take a screenshot, but it saves a blank image...