Creating regions
You can convert a closed entity into a two-dimensional region. After you create a region, you can modify it using the various three-dimensional tools. For example, you can create a region from a square, and then extrude the square to create a three-dimensional cube.
You can create regions from closed entities, such as polylines, polygons, circles, ellipses, closed splines, and donuts.
Creating regions typically has no visible effect on a drawing. However, if the original entity had a width or lineweight, that information is lost when you create the region.
To create a region
1 Do one of the following to choose Region ():
On the ribbon, choose Draw 3D > Region (in Draw 3D Solids).
On the menu, choose Draw > 3D Solids > Region.
On the Draw 3D Solids toolbar, click the Region tool.
Type region and then press Enter.
2 Select the entities to create the region.
3 Press Enter.
The command bar displays a message that describes how many regions were created.