A dummy viewport type that passes through the image for testing.
bool - When enabled, viewport is drawn to the screen
vec4f - The viewport bounds, scaled on the screen by the ViewportLayout size. (e.g. layout size 2.0, 1.0, and child viewport width 1.0 will fill half the screen with the viewport)
link - The camera from which the scene is rendered
bool - if true some of the image seen in the rift will be cropped when displayed in the main window.
bool - if true then both eyes will be displayed in a split screen fashion