Reverse polygon normals
Select the faces you want to reverse:Select Mesh Display > Reverse > in the Modeling menu set.Set the Reverse normals on option to one of the following: To reverse the face normals of selected faces, choose Selected faces. Click Reverse Normals.

How do you flip in Blender?

To mirror a selection along a particular global axis press: Ctrl-M , followed by X , Y or Z . The image Mirroring a Selection shows the results of this action after a mesh element has been duplicated.

How do you invert a selection in Blender?

Assign “Alt+A” to invert the selection. ⁠— Right-Click Select. Assign “Alt+A” to invert the selection.

How do you invert a mask in Blender?

In order to edit the mask, select the Mask Brush from the Brush panel. Masks can be edited across the entire model: Invert Mask Ctrl-I.

How do you bridge in blender?

To use the Bridge Edge Loops tool:
Select a string of edges (edge loop).Select another edge loop in a separate part of the model (for optimal results, both edge loops should have the same number of edges).Press Ctrl + E to access the Edge menu and select the Bridge Edge Loops