Packing

Packing can be done from within the Cut UV tool as well. The record button on the left toggles automatic packing after every action and the play button on the right packs whenever you click it.

The Include option in the UV Flow pack menu determines which faces get packed together. Selected Faces will pack all selected faces together and Selected Objects will pack all faces of the selected objects together. Selected Materials will pack all faces of every object in the scene that shares the same material as the selection (when packing in Edit Mode) or the active material (when packing in Object Mode).

The Group setting determines which islands get packed into the same UV Space. You can either pack all islands together, pack objects together, or pack materials together.

The Shape setting controls the accuracy and speed of your pack. Bounds is the fastest and packs as if each island is a simple rectangle. Convex is slower and takes the outside shape of the island into account but does not support holes or concave features. Concave is the slowest but uses the actual shape of the island to create as perfect of a pack as possible. Because of the speed tradeoff, it’s recommended to use Bounds while working initially and then use Concave to create the final pack at the end.

Pack To either places your island within the closest UDIM, the active UDIM, or the bounding box of the island before it was packed. If you are not using UDIMs, the first two options will just pack all islands to the default 0 to 1 UV space.

Merge Overlapping will cause any overlapping islands to be packed as one island. This is helpful when duplicated or mirrored UVs are laid directly on top of each other.

Lock Pinned allows you to control how much your pinned UV islands are transformed during packing.

Average Scale will apply an Average Island Scale operation to all of the UV Islands before packing so that they will all share the same texel density.

Rotation determines how much each island is allowed to rotate when packing. Allowing full rotation will result in a tigheter pack but may also result in skewed islands which will make it impossible to draw perfectly straight lines. The Cardinal option will only rotate the islands in 90 degree increments while the Axis Aligned option will rotate the islands to fit to the smallest possible vertical or horizontal bounding box.

The Margin Amount controls how much space is between each UV island. It is always recommended to have at least some space so that pixels from one island won’t bleed onto its neighbors. If the application you’re going to render in supports Mip Mapping, such as most game and real-time engines, be sure to use at least 1.6% so that textures displayed farther won’t have bleeding between islands. The Fast method is quick to compute and a very rough approximation while the Exact method is slower but ensures pixel perfect padding.