1. A method for use in a CAD system, comprising: loading an object model in a CAD system, the object model including a blend face; finding underfaces of the blend face by the CAD system; constructing an intersection curve, by the CAD system, according to the underfaces; trimming the intersection curve according to the blend face, by the CAD system, to produce a virtual blend curve; and storing the virtual blend curve in the CAD system.