Yes, you can modify an imported file.
What do you need to do, specifically, that you are having trouble with? What software did you import your file from? What file type did you import?
I am a contract engineer in Austin TX that is looking for ways to make modifications, specifically add machining stock in places the client requests on imported files that are typically derived by 3D scanning of the original shape. In a lot if cases the added stock is on a surface that is not planor. I typically am able to import the file, get through the import diagnostics snags and do some feature recognition of the scanned model. I am have a licensed copy of Solidworks 2014 Premium(middle of the road version) I would like to be able to better understand how to successfully import these files get all or most of the features recognized and in the end be able to add stock in place that the client requests.
I am contacting you because I did a search on this forum and your response led me to believe you might be someone that can help with this. My goal today is to full court press this issue in the hopes I can find a workable solution that will work for my business. If you have any information that will get me closer to solving this I would appreciate hearing from you.
Austin, TX 78704
Depending on the software these files are coming from, Solidworks will import directly files that come from Inventor, Pro-E and Catia.
When it brings these files into solidworks you have the option to recognize features upon import. Understand that while the features might come in and look ok, they are not constrained at all. So you will have to edit the sketches and dimension them accordingly.
When dealing with imported parts, you will save yourself a lot of time and frustration by using the Move Face and/or other techniques, rather than trying to recognize features to edit.
If you can post a sample part and explain the edits required, someone will be able to give examples.
You could also attempt to heal faces if any errors occured, typically what I do if I need to edit an imported part is create new planes under reference geometry and make them tangent or linear to the face I'm trying to enhance and go from there.