- Disable texture streaming
- AScreenshotFunctionalTest now reads back from game viewport directly when taking screenshot
- AFunctionalUIScreenshotTest now render into a custom render target using FWidgetRenderer so that UI screenshot can be captured at fixed size
- Add a new class, AScreenshotFunctionalTestBase, that handles screenshot common functions. AScreenshotFunctionalTest and AFunctionalUIScreenshotTest now derive from it
#rb Chris.Bunner
#codereview Chris.Bunner
#lockdown nick.penwarden
[CL 3647910 by Jian Ru in Main branch]
