post the family.
also post an image showing what you are talking about.
@sak9537 wrote:
yes
You can't.
Either find a similar family that was modeled using Solid or Nurbs, not Surface or Polyface, or turn off the 3d model of the family for 2D Plan/RCP/Elevation presentations, draw symbolic line or filled region for 2D presentations, and keep the 3D import for rendering only.
Example of a cleanly built family from a furniture vendor library.
If you want to remove those lines, you need software like 3ds Max.
https://www.youtube.com/watch?v=F7Z4qT8S29s&ab_channel=scourdx