Insert dummy part that contains wireframe geometry or create wireframe geometry in existing part as itsmyjob said.
We have some customers that work in this way. Vectors in one part, body another part. Actually I don't get that. What is a benefit of doing so?
Thanks, I have a iges (converted) compound surfaces shape with "holes" and need the figure out the center line relative to a master model defining where the holes should be. I combined the two in to a product but cannot measure anything from the iges model. Probably not the best way to do this.