Viewports in the Level Editor of Unreal Editor provide the ability to display a picture-in-picture preview of Camera Actors placed in the world when they are selected. This makes it extremely easy and intuitive to place or orient cameras as well as tweak their properties.
This feature may cause performance to degrade, especially when multiple cameras are selected.
Selecting a Camera Actor shows a preview of that camera overlaid in the active Viewport.
The preview is not displayed when a selected camera is locked to the active Viewport using the Piloting option in the right-click context menu.
When multiple Camera Actors are selected, a preview for each one is displayed.
Previews become transparent when the mouse hovers over them to allow for manipulation of the scene that would otherwise be obscured by the preview.
Translation or rotation of the camera using the transform tools will be reflected in the preview.
Properties of the selected camera update in real-time as properties are tweaked using the Details panel. The preview is capable of displaying post-processing effects, making it perfect for setting up cameras for cinematics.
The preview feature can be toggled on or off in the Viewports section of the Editor Preferences window (Edit > Editor Preferences).