I come to Blender from the CAD world. I am teaching Blender to 12 students. We are working on a scene that happens in Charleston Harbor in 1862. I found an old chart and scaled it to full size using AutoCAD. Then I traced it making closed polylines. I can bring it into Blender as an FBX, but those closed shapes come in looking like this image:
I want to make a landscape using the shapes I created, giving it height. Do any of you know how I might un-fill the shapes?