Fill Tool Options
The following options are available in the Options panel:
| Extend Fill | Fills selected edges by extending the neighboring faces.   | 
| Patch Fill | Fills the selected edges using the initial tangency of
                                neighboring faces to create a smooth patch.   | 
| Tangent to all sides | Available for Patch Fill. Makes the patch tangent when possible to the neighboring faces. | 
| Show UV grid | Enabled for Patch Fill. Displays a grid on the Fill preview to
                                help visualize the contours. Use the dropdown slider to adjust the
                                density of the grid.   | 
| Show deviation | Enabled for Patch Fill. Shows a Deviation analysis of the patch. You can set the color and scale used to display the analysis. | 
In the Fill tool, using the Patch option, fill multiple areas at once using Alt-selected tangency influences and preview the changes. In the example, the two loops are being filled simultaneously and previewed. Notice the preview change when a different Point is Alt-selected.
