Adds support for grid surfaces such as NURBS or Bézier surfaces.

• New markup type called GridSurface that shows up in the Markups module
• Placement by the three initial control points defining three of the four corners thus the surface plane. The fourth corner is added symmetrically.
• The grid control points are added automatically to uniformly fill the defined surface area
• The surface can be edited by moving the control points
• Output model node can be associated for the surface patch the display options of which can be edited in the Models module

Example NURBS surface:

NURBS surface wrapped around (i.e. cylinder-like) shaped like a heart valve:

Example Bézier surface:

• The Cora Topolewski Fund at the Children's Hospital of Philadelphia (CHOP)

• CHOP Frontier Grant (Pediatric Valve Center)

• National Heart, Blood, and Lung Institute (NHLBI) (R01 HL153166)