Daylight points (green) derive their elevation from the Existing surface. Daylight Lines exist only in the Design Surface and automatically update to reflect changes made to the existing ground whenever the trimesh grid is recalculated. The trimesh grid recalculates any time the terrain view is enabled after editing. Daylight points are created by either entering the point with an elevation of (.) using the Period key or selecting it and changing the entire line to daylight by pressing the D button at the top of the Elevation Dialog window.