Editing

After unwrap, you will likely need to arrange the UV maps, so that they can be used in texturing or painting. Your goals for editing are:

Stitch pieces (of UV maps) back together.
Minimize wasted space in the image.
Enlarge the faces where you want more detail.
Re-size/enlarge the faces that are stretched.
Shrink the faces that are too grainy and have too much detail.

With a minimum of dead space, the most pixels can be dedicated to giving the maximum detail and fineness to the UV texture. A UV face can be as small as a pixel (the little dots that make up an image) or as large as an entire image. You probably want to make major adjustments first, and then tweak the layout.

Transform

Reference

Editor: UV Editor
Mode: Edit Mode
Tool: Toolbar ‣ Move, Rotate, Scale, Transform
Menu: UV ‣ Transform

Move G
Rotate R
Scale S
Shear Shift-Ctrl-Alt-S

Axis Locking

Transformations can be locked to an axis by pressing X or Y after one of the transform tools. Also, holding the MMB will constrain movement to the X or Y axis.

Mirror

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Mirror
Shortcut: Ctrl-M

UVs can be mirrored on the Y axis or the X axis:

Mirror X
Mirror Y

You can also use the hotkeys X or Y, or hold the MMB and drag in the mirror direction.

Copy Mirrored UV Coordinates

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Copy Mirrored UV Coordinates

Copies UVs from one side of the mirrored mesh to the other. Affects only selected vertices (on both sides).

Axis Direction: Positive/Negative
Precision: Tolerance for finding vertex duplicates.

Snap

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Snap
Shortcut: Shift-S

Snapping in the UV Editor is similar to Snapping in 3D. For the snap to pixel options to work an image has to be loaded.

Selected to Pixels: Moves selection to nearest pixel. See also Snap to pixel above.
Selected to Cursor: Moves selection to 2D cursor location.
Selected to Cursor (Offset): Moves selection center to 2D cursor location, while preserving the offset of the vertices from the center.
Selected to Adjacent Unselected: Moves selection to adjacent unselected element.
Cursor to Pixels: Snaps the cursor to the nearest pixels.
Cursor to Selected: Moves the Cursor to the center of the selection.
Cursor to Origin: Places the cursor to the location (0, 0, 0).

Merge

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Merge
Shortcut: M

At Center: Moves selected UVs to their average position.
At Cursor: Moves selection UVs to 2D cursor location.

By Distance: Merges selected UVs within the specified Merge Distance.

Split

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Split
Shortcut: Alt-M

Selection Y

Splits (disconnects) the selection from the rest of the UV. The border edge to any non-selected elements are duplicated.

Note that the "copy" is left exactly at the same position as the original, so you must move it to see it clearly.

Unwrap

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Unwrap
Shortcut: U

Blender offers several ways of mapping UVs. The simpler projection methods use formulas that map 3D space onto 2D space, by interpolating the position of points toward a point, axis or plane through a surface. The more advanced methods can be used with more complex models, and have more specific uses.

Pin & Unpin

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Pin/Unpin
Shortcut: P, Alt-P

You can pin UVs so they do not move between multiple unwrap operations. When Unwrapping a model it is sometimes useful to "Lock" certain UVs, so that parts of a UV layout stay the same shape, and/or in the same place. Pinning is done by selecting a UV, then selecting Pin from the UVs menu, or the shortcut P. You can Unpin a UV with the shortcut Alt-P.

Pinning is most effective when using the Unwrap method of UV mapping, for organic objects. An example is when you are modeling a symmetrical object using the Mirror Modifier. Some of the UVs on the mirror axis may be shared across the mirrored counterparts. You could pin the UVs that correspond to the midline, then align them on the X axis, and they will stay in that location.

Pinning also work great with the Live Unwrap tool. If you pin two or more UVs, with Live Unwrap on, dragging pinned UVs will interactively unwrap the model. This helps with fitting a UV island to a certain shape or region.

Mark/Clear Seams

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Mark/Clear Seam

See Seams.

Seams from Islands

Reference

Mode: View mode
Menu: UV ‣ Seams from Islands

Adds seams at the boundaries of existing UV islands. This is useful when modifying the UVs of already unwrapped meshes.

Pack Islands

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Pack Islands

The Pack Islands tool generates an optimized UV layout with non-overlapping islands that tries to efficiently fill the Texture Space.

First it will uniformly scale the selected island, then individually transform each island so that they fill up the UV space as much as possible.

Pack To

The UDIM grid to pack UV islands into.

Closest UDIM: Pack islands to closest UDIM.
Active UDIM: Pack islands to active UDIM image tile or UDIM grid tile where 2D cursor is located.

Rotate

Allow islands to be rotated to possible get a tighter fit.

Margin

The target empty space between islands.

Average Island Scale

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Average Island Scale

Using the Average Island Scale tool, will scale each UV island so that they are all approximately the same scale.

Non-Uniform: Reduces average texture stretching within islands by scaling the U and V axes independently.
Shear: Reduces average texture shearing within islands by shearing the U axis.

Minimize Stretch

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Minimize Stretch

The Minimize Stretch tool, reduces UV stretch by minimizing angles. This essentially relaxes the UVs.

Stitch

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Stitch
Shortcut: Alt-V

The Stitch tool, will join selected UVs that share vertices. You set the tool to limit stitching by distance in the Adjust Last Operation panel, by activating Use Limit and adjusting the Limit Distance.

Align

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Align
Shortcut: Shift-W

The Align tool will move the selected UVs to a line, where that line is specified in different ways by Axis.

The Straighten option will calculate a line segment between two endpoints and move all selected UVs onto that line.

The Align X and Align Y options will axis-align all selected UVs to the midpoint of the current selection.

Axis

Straighten: Move UV to closest point on line segment.
Straighten X: Move U co-ordinates onto the line.
Straighten Y: Move V co-ordinates onto the line.
Align X: Move U co-ordinates to the midpoint of the selection.
Align Y: Move V co-ordinates to the midpoint of the selection.
Align Auto: Choose between Align X or Align Y automatically.

Show/Hide Faces

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Show/Hide Faces

Reveal Hidden Alt-H
Hide Selected H
Hide Unselected Shift-H

Export UV Layout

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UV ‣ Export UV Layout

If you are using an external application, you need to know where on the mesh you are painting.

Catatan

This is an add-on activated by default.

Proportional Editing

Reference

Editor: UV Editor
Mode: Edit Mode
Header: Proportional Editing
Menu: UV ‣ Proportional Editing
Shortcut: O

Proportional Editing is available in UV editing. The controls are the same as in the 3D Viewport. See Proportional Editing in 3D for a full reference.

UV Options

Reference

Editor: UV Editor
Mode: Edit Mode
Menu: UVs

Live Unwrap: Continuously unwraps the selected UV islands while transforming pinned vertices. Note, this is different than the Live Unwrap option in the 3D Viewport.

Snap to Pixels

Disabled: UVs will not be snapped.
Corner: Will force the UVs to snap to the corners of the nearest pixels of an image if loaded.
Center: Will force the UVs to snap to the center of the nearest pixels of an image if loaded.

Constraining to Image Bounds: For standard textures, this option prevents UVs from being moved outside the 0 to 1 UV range. For UDIMs textures, this option prevents UVs from being moved outside the nearest UDIM tile.

3D Viewport

Rotate UVs

Reference

Editor: 3D Viewport
Mode: Edit Mode
Menu: Face ‣ Face Data ‣ Rotate UVs

The orientation of the UV texture is defined by each face. If the image is, for example, upside down or laying on its side, use the Face ‣ Rotate UVs (in the 3D Viewport in Face Select mode) menu to rotate the UVs per face in 90-degree turns.

Reverse UVs

Reference

Editor: 3D Viewport
Mode: Edit Mode
Menu: Face ‣ Face Data ‣ Reverse UVs

The Face ‣ Reverse UVs tool mirrors the UVs per face, which flips the image over, showing you the image reversed.