I created two Development builds in the binary version of Unreal Engine 4.18; one with Metal v1.2 and one with Metal 2.0. When running both builds on an iPhone 7 Plus running iOS 11.0.3, I receive the following pop-up when the I try to launch the application:
OpenGL Not Supported
You must have a Metal compatible iOS or tvOS device with iOS 8 or later to launch this app.
Tapping Ok closes the app. It won’t go past this screen.
It is my understanding 4.18 does not support OpenGL at all. What’s going on here?
I just tried a Shipping build, and the same error happened.
I have found the issue. In the DefaultEngine.ini file for the project, in the [/Script/IOSRuntimeSettings.IOSRuntimeSettings] section, the bSupportsMetal flag was set to False.
I recall when adjusting the iOS project settings, in the Rendering section I was able to deselect the Metal Mobile Renderer option, with the Metal Desktop-Forward Renderer option also deselected. This flipped the bSupportsMetal flag to false, while not adding the bSupportsMetalMRT flag to the ini file; causing the ini file to indicate the project only supported OpenGL.
I set the bSupportsMetal flag to True in the ini file, and was able to make a build that runs perfectly on an iPhone 7 Plus on iOS 11.0.3
