CAD how do entities surface? ? ?

I have access to the software at the more detailed the better I already know how to generate surface is not sure how it will be translated into physical
I heard people saying they have to face into a domain boy is hope you do not know ah You know the answer to the xian XIE

directly EXT try for a closed two-dimensional graphics on the can,
also Based on the path to pull into a variety of three-dimensional shape of the surface domain to ensure that your face is two-dimensional, that is the domain you want to face that, if not in the same flat wireframe is not the domain of the surface, CAD surface is not so ideal The software, so you Huadianxinsi or more in the CAD on the plane, after the physical surface so you can learn proe that UG and it is up to you to do what you normally curved surface or surface Senior General Surface Generation Rotary has swept again face difficult The line is the dimensions where you will put it much
but I still suggest you CA is two-dimensional software, is not suitable if you use three-dimensional modeling CAD three-dimensional modeling is also not a bad idea.
As to whether the CAD To face into a domain, this should be it.