iOS Debugging and Optimization - Learning Unreal Engine iOS Game Development - page 187

Capturing frames
You can also use the Capture OpenGL ES Frame option from the Debug menu, which
will freeze the game for a while and totally change the content of the Debug menu to ac-
commodate the new debugging environment. Finally, it shows you a frame debugger that
contains all of the draw calls for OpenGL ES where you can see the construction and the
rendering pipeline of the chosen frame. Also, you can check the used texture, shaders, and
objects one by one. It is a more advanced tool, but it is very useful to use when you want to
really understand how a frame gets rendered step by step.
From the changed Debug menu, you can go back and forth between the draw calls. Once
you have finished investigating, you can go to the Debug menu again and choose Release
OpenGL ES Frame . This will let the game keep running again on the device. Keep in
mind that these options are available only when you have a game running on the device.