Unfold UV and Optimize UV Tools

To open the Unfold UV Tool or Optimize UV Tool, select it from the Unfold section in the UV Toolkit or select Tools > Unfold or Tools > Optimize 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 Tools > Unfold > or Tools > Optimize > .

Unfold3DBrush Options

Mode
Toggles between Unfold and Optimize tools.
Brush Size
Sets the radius of the tool.

Hotkey: B + drag left/right to adjust the brush size.

Brush Pressure
Determines how much the tool affects the surface.

Hotkey: M + drag up/down to adjust the brush strength.

Iterations
Specifies the number of times the Optimize algorithm is performed after the Unfold process completes (i.e. a value of 0 will unfold the mesh without any optimizations).
Note: A very high number of iterations may produce undesirable results.
Surface Angle
Controls the strength of the surface and angular optimization, minimizing stretching and angular errors in your UV map. The default value is 1.
Note: This option is only available when Optimize is selected.