The Region by Boundary tool allows you to create regions when you are in the process of creating a new model or adding to an existing model. To access this tool, click 
().
The Region by Boundary command is used to define the shape of a part surface.
Dialog elements
- Select curves
- Allows you to select the curves that define a region boundary. Click and drag the cursor to select the required curves.Note: If your selection contains more curves than the visible box holds, the box scrolls so that all selected curves can be seen.
- Search
- Finds all curves that are sequentially connected to the selected curve. Note: If the search reaches a point where possible connected curves start to diverge, the search stops and only the curves found up to that point are selected. You need to manually select any remaining curves.