Control for holding [SubViewport]s. A [Container] node that holds a [SubViewport], automatically setting its size. [b]Note:[/b] Changing a SubViewportContainer's [member Control.rect_scale] will cause its contents to appear distorted. To change its visual size without causing distortion, adjust the node's margins instead (if it's not already in a container). If [code]true[/code], the sub-viewport will be scaled to the control's size. Divides the sub-viewport's effective resolution by this value while preserving its scale. This can be used to speed up rendering. For example, a 1280×720 sub-viewport with [member stretch_shrink] set to [code]2[/code] will be rendered at 640×360 while occupying the same size in the container. [b]Note:[/b] [member stretch] must be [code]true[/code] for this property to work.