I have set up the linework code set and the figure prefix database where I noted which figures were to be breaklines. I then imported the ASCII coordinate final to the survey database, processing the linework as it is imported. I create a surface then modify the surface by importing a point group and create a tin, but the figures in the drawing are not being recognized as breaklines.......what am I doing wrong ?
Hard to say... C3D has LOTS of settings that can create a problem.
But my first guess is that you didn't select the breaklines in the Survey Database and do Right cliick->"Insert Breaklines". If you've already tried that, and it fails, then it's probably a settitng in your Desc Keys, your Figure Prefix Lib, or your Styles/Layers.