To Separate Surface Regions using Automatic Selection
1. Click > > 
Separate Surface Region. The Separate Surface Region tab opens.
Separate Surface Region. The Separate Surface Region tab opens.2. Click 
Auto-detect.
Auto-detect.3. To select a surface from which to separate surface regions, click the Surface to separate collector, and in the graphics window, select a surface.
4. To select contours to keep in the source surface, click the Placement tab, click the Contours to keep collector, and in the graphics window select contours to keep. All the other contours are separated into a new surface.
5. Click the Options tab and select an option:
◦ To create a separate surface for each selected contour, select For each selected contour separately.
◦ To create one single surface for all the selected contours, select For all selected contours together.
6. Click 
OK.
OK.