Some people will be shocked by the title of this article.
How can you say that SolidWorks can do direct modeling when every operation you perform on the model is documented in the feature tree?
Let me start by saying that if the definition of direct modeling includes loosing track of the operations you perform on the affected geometry, then SolidWorks does not have direct modeling capabilities.
But if you need to modify existing solid bodies, regardless of how they were created, then I can tell you that SolidWorks has the capabilities that you are looking for!
This video present a very good example on how you can perform a complex change affecting a local area of an imported body using SolidWorks. The update is fast, easy and you are always in control. There is never a danger of doing an operation that would consume an existing entity (face, edge) without having the option of retracing your steps.
Once you finished modifying your part, you still have options for freezing the feature tree (so the rebuild time will be zero) or completely removing the history by saving the model in a neutral format (I prefer Parasolid X_T) and re-importing it back in SolidWorks.
If you design tooling, fixtures, nests or have a 3D Printer, please CLICK HERE for another interesting case study about using SolidWorks Direct Modeling Techniques for patching existing geometry from an imported body.