According to one embodiment of the invention, a method for interfacing with a surface within a computer-aided drawing environment includes determining that a plurality of curves operable to define the surface constitute a P×1 surface condition. A P×1 surface condition is defined by a number of first curves equal to P and only one second curve. P is an integer greater than zero. The method also includes converting the P×1 surface condition into an N×M surface condition in response to determining that a plurality of curves constitute a P×1 surface condition. An N×M surface condition is defined by a number of third curves equal to N and a number of fourth curves equal to M. N and M are integers greater than one. The method also includes constructing an N×M surface under the N×M surface condition. The method also includes modifying the N×M surface to edit a drawing.