Line to surface edge gaps

Will someone please remind me of what I know about why gaps are generated between lines and surfaces developed from the lines?

Gaps are shown in the attached adjascent to the red leader dots.

How can this be eliminated?

SRF TO LINE GAP.pdf (233.9 KB)

Hi -

To show a surface in a viewport, the NURBS surface needs to be approximated by a mesh. In curvy areas, there will always be a difference between the true curve and the straight edges of the triangles in the display mesh. That difference can never be completely eliminated but can be limited - Rhino Mesh Settings [McNeel Wiki]