Create Polylines from Regions

[GradientWind]

This other program I am using can import a 3D object, such as a building, as long as each face of the building is a closed polyline.

My building is a square (as seen from above) and I extruded it upwards to whatever height. I then exploded the solid and each face was a region. How can I convert all the regions to closed polylines? Ideally, I would like to select everything and in once action, convert all regions to closed polylines.

Thanks

[nestly2 · Accepted solution]

I think you'll likely have difficulty automating the process because Polylines are 2D objects, therefore even when you have polylines on the edges of faces/regions, they'll all have to share a common UCS in order to be joined/closed.

FYI, If you EXPLODE the regions, you'll be left with polylines, but they won't automatically be "closed"   Similarly, XEDGES command will create wireframe geometry (polylines for straight segments) without needing to EXPLODE the solids, but they won't automatically be "closed"