• Switch into Boundary Patch Surface Creation mode by pressing the tool or by selecting "Boundary Patch Mode" from the Surfaces sub-menu (ribbon toolbar’s Create Tab). Note that the boundary patch is similar to the Path Surface but it a) is always a NURBS surface, b) takes only 2 to 4 objects in the path/boundary, and c) creates a bilinear Coons patch.
The cursor will change to the boundary patch surface cursor.
• Select the first object of the path from a photo, 3D view or table.
The selected object will highlight.
• Select the second object of the path from a photo, 3D view or table.
The second object will highlight and a path will be drawn on any open photographs with marks for all items in the path If the selected objects are 3D and the minimum requirements for a path are met the surface will also display in 3D.
If the line, edge or curve you select is not added to the path in the direction you need you can use the "Reverse Last Object" command, located on the Surface sub-menu, to reverse it.
• Continue with selecting objects to complete the path. Four boundary curves is the maximum. If four are chosen the curves and lines much meet at their corners at common points.
• Depending on the number of objects chosen the path will close automatically and the boundary patch will be created or if selecting fewer than four boundary objects you can select "Finish Surface" from the right-click or surface menu (ribbon toolbar’s Create Tab).
The path outline displayed on any open photos will erase and the surface be added to the project.
Note 1: since by definition a close curve is closed path it cannot be used in a boundary patch.
Note 2: the direction a boundary patch faces is determined by the direction (clockwise or counter-clockwise) its path is selected. If the surface you create does not face the direction you would like you can use the "Flip Surface(s)" command, located on the surface sub-menu. This command will flip the currently selected or, if no surfaces are selected, the last created Surface. Surfaces also have a "double sided" property that will mean a surface 'faces' in both directions. See Surface Properties.