Expert: Kevin Stohlmeyer - 4/10/2008

Question
Hi. I need to trace the outer perimeter of a large set of moderately complex drawings. The drawings were exported from AutoCad into Illustrator CS3 via dxf and dwg files so where a rational person would create a drawing using polygons or curves these drawings are made of thousands of straight line vectors. Joining the individual line segments isn’t really practical and since there are no filled objects the pathfinder tools don’t seem to do much. I’ve tried the path offset tool but that seems to trace the individual line segments. What I really need is a closed polygon in the shape of the outer perimeter but the drawings are too complex and too numerous to trace by hand with the pen tools. Is there another approach? Thanks.

Answer
Hi Bob,

Unfortunately, this is a draw back of importing a CAd drawing into Illustrator. One thing I need to warn you of is the fact that you keep saying this is a complex drawing. Something too complex can cause Illustrator to choke very easily so be careful.

If these are all individual paths and not connected at all, which is common with CAD imports, using Object>Expand will not work for you. You can try the Object>Path>Join command, but that may take too much time.

Sometimes the best option is not the easiest, which would be to trace the outer perimeter by hand. That is the only way if you are trying to fill with a color.

I wish I could give you better news, but I've dealt with this many times, and the answer is never what people want to hear.

Thanks

Kevin