To open the Unfold UV Tool, click the icon on the UV Editor toolbar or select Tool > Unfold UV Tool from the UV Editor menus.
To open the Optimize UV Tool, click the icon on the UV Editor toolbar or select Tool > Optimize UV Tool from the UV Editor menus.
The Unfold UV Tool lets you interactively unwrap the UV mesh for a polygonal object while trying to ensure that the UVs do not overlap. Unfolding UVs helps to minimize the distortion of texture maps on organic polygon meshes by optimizing the position of the UV coordinates so they more closely reflect the original polygon mesh.
The Optimize UV Tool evens out the spacing between UVs on a mesh, fixing areas of distortion (overlapping UVs).
The following options appear in the Tool Settings window when you select Tool > Unfold UV Tool > or Tool > Optimize UV Tool > .
Hotkey: B + drag left/right to adjust the brush size.
Hotkey: M + drag up/down to adjust the brush strength.