Building surfaces is also possible using 3D projections and it works in a very similarly manner to the 2D case.
With 3D projections, the command BUILDÞCreate:Surface creates the surface by transforming one or more 2D sections to match the 3D projection curve locations to make a wire framework and then ‘stretching’ a surface over this framework. The projection and section curves may be either B-splines or Bézier, but the resulting surface will always be created in the Bézier format.
The other BUILD menu commands, such as BUILDÞCreate:Cross Sections, BUILDÞSet:Build Parameters and BUILDÞSet:Section Parameters work for 3D projections, too. However secondary projections do not have any meaning in the 3D case.
With two 3D-projection curves, the section curves should normally be open. The section curves are scaled between the projection curves by matching the section curve endpoints to the projection curve placement points. The command works also with closed section curves, fitting the cross-sections between the projections, but with reduced accuracy.