Determines how UI elements in the Canvas are scaled.
| ConstantPixelSize | Using the Constant Pixel Size mode, positions and sizes of UI elements are specified in pixels on the screen. |
| ScaleWithScreenSize | Using the Scale With Screen Size mode, positions and sizes can be specified according to the pixels of a specified reference resolution. |
| ConstantPhysicalSize | Using the Constant Physical Size mode, positions and sizes of UI elements are specified in physical units, such as millimeters, points, or picas. |