How to convert 3D drawing drawn using the line in the 3D object?I need to draw some wood board with the hole in the botom side. I draw the board via line in 3D looks and hole I draw via circle which extrude. When I change the visual style to the Conceptual, only hole looks like 3D object and board not. How to convert board to the 3D object?http://imagizer.imageshack.us/v2/800x600q90/854/zfs4.jpg

Draw the board then use the PressPull command to give it height.  PressPull works on any combination of lines, arcs, polylines and splines.Or....draw the board using one continuous polyline then use the Extrude command to give it height.To create a hole through a board or a portion of the board use the Subtract command.One other way to create a solid is to use the Thicken command on a surface.

rdjavi: I heard from my twin brother that you posted the same question at the CADTutor forum.  He has decided to help you by creating a sample 3D drawing.  You might want to go there and take a look.