Canvas

The Canvas entity does not render anything, but just contains different data for the OrthogaphicRenderSystem to render. This includes information such as Mesh vertices/indices, the size of the canvas, its children, and how many submeshes the Canvas has.

Canvas Rescalings

When the Screen Resolution does not match the Canvas' dimension, the CanvasScaleSystem kicks in to tell the canvas to rescale itself. This ensures that the root is correctly scaled so that when the AnchorSystem runs, the correct relative screen spaces are used to recompute the anchor.