I have these contour lines (converted from shapefile to CAD file in ArcGis software) imported to Sketchup Pro.
I want to make a terrain from these , so I used the From contours tool in Sandbox toolbar, but it gives me this error message!
As you see, I selected the lines before clicking on the tool, so I do not know why I get this message. Any idea if there is something wrong with my contours or am I doing something wrong? Thanks.