Overview

The Fill tool is used to fill a space based on selected edges or vertices. With no selected elements(edges or vertices) when entering the tool, the tool will search for holes in the designer object so that you can fill them easily.

This tool will be very useful to correct a geometry.

How to use

From the Selected Edges.

1. Separated two opposite edges
   if you want to fill a space between two opposite edges, you should select the two edges with the Edge tool and then click the fill button in the menu panel.
   
   Then the space between the two edges will be filled as upper picture.
   
   
   
2. Connected more than two edges.
   You can fill a space surrounded by multiple edges as the following image. With the help of the Loop Selection tool, you can select multiple edges surrounding a space easily.
   
   After selecting edges connecting each other, click the "Fill" button in the menu panel then the space will be filled.
   
   In order to fill a space looking like a polygon consisting of n edges, you can choose n-1 edges as well as n edges.
   

From the Selected Vertices.

At least 3 vertices should be selected to fill a space. The order of selecting vertices is important.

After selecting vertices, press the Fill too then the space defining the vertices will be filled.

By Selecting a hole.

If you enter the Fill tool without any selected edges or vertices, The fill tool will search for holes existing in the designer object.

When the mouse is over a hole, the hole will be highlighted.

You can fill the highlighted hole by clicking LMB.

The holes looking like the following screenshot aren't searched for by the Fill tool.

In this case you should select edges or vertices as follows to fill the space.

And then click the Fill button.