I made some models in Blender and exported them using modifers. When I exported them as .3ds, collada. and .obj and imported them (in this case, Sketchup), all the vertices show up where it would be a smooth surface when it was in Blender. I tried Joining them (in Blender), but it didn’t help.
I imagine there is a proper procedure that I am ignorant of.
You need to supply examples of what you are talking about.
What objects
What modifiers
What export/import settings
What do you mean by ‘smooth surface’. Were you expecting a rough surface ? if so what does that look like.