To Create a Rib Top Feature
1. Click > 
Ribtop.
Ribtop.The Rib Top Feature dialog box opens with the following elements:
◦ Feature Name—The default feature name, such as RibTop1 (the system increments the number for the next Rib Top feature). You can type a customized name.
◦ Define Feature Floor—Select the Floor surface for the feature (the top of the rib).
◦ Adjust Feature Boundaries—Change the shape of the feature walls using Sketcher.
◦ Define Program Zero—Change the coordinate system used for feature definition and machining.
◦ Adjust Soft Walls—Change Hard Walls to Soft and Soft Walls to Hard.
2. Select the Floor surface(s). On the SELECT SRFS menu, click Done/Return.
3. Use the other elements, if needed. Click 
next to the element to display the current setting. The Preview button lets you check the feature geometry by highlighting the Hard Walls in red, Soft Walls in cyan.
next to the element to display the current setting. The Preview button lets you check the feature geometry by highlighting the Hard Walls in red, Soft Walls in cyan.4. Click OK to complete the feature, Cancel to quit.