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.

Vertex Slide

Reference

Mode:

Edit Mode

Menu:

UV ‣ Transform ‣ Vertex Slide

Vertex Slide will transform a vertex along one of its adjacent edges. Use Shift-V to activate tool. The nearest selected vertex to the mouse cursor will be the control one. Move the mouse along the direction of the desired edge to specify the vertex position. Then press LMB to confirm the transformation.

Factor

Determines the amount of slide performed. Negative values correspond to slides toward one vertex, while positive ones, refer to the other one.

Even E

By default, the offset value of the vertices is a percentage of the edges length along which they move. When Even mode is active, the vertices are shifted by an absolute value.

Flipped F

When Flipped is active, vertices move the same distance from adjacent vertices, instead of moving from their original position.

Clamp Alt or C

Toggle clamping the slide within the edge extents.

Edge Slide

Reference

Mode:

Edit Mode

Menu:

UV ‣ Transform ‣ Edge Slide

Slides one or more edges across adjacent faces with a few restrictions involving the selection of edges (i.e. the selection must define a valid loop, see below).

Factor

Determines the amount of slide performed. Negative values correspond to slides toward one face, while positive ones, refer to the other one.

Even E

Forces the edge loop to match the shape of the adjacent edge loop. You can flip to the opposite vertex using F.

Flipped F

When Even mode is active, this flips between the two adjacent edge loops the active edge loop will match.

Clamp Alt or C

Toggle clamping the slide within the edge extents.

Mirror Editing

Lets you propagate the operation to the symmetrical elements of the mesh (if present, in local X direction).

Randomize

Reference

Editor:

UV Editor

Mode:

Edit Mode

Menu:

UV ‣ Transform ‣ Randomize

Randomize the scale, rotation and offset of selected UV islands. The Randomize Transform tool in the UV editor works similar to Randomize Transform tool in the 3d view.

Random Seed

Changes the random seed used by the pseudo-random number generator, producing a different transform result for each seed value.

Location

Amount to randomize location.

Rotation

Amount to randomize rotation.

Scale Even

Apply the same scale to the U coordinate and V coordinate.

Scale

Amount to randomize scale in U and V coordinates.

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 Round to Pixels below.

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.

• Unwrap

• Smart UV Project

• Lightmap Pack

• Follow Active Quads

• Cube Projection

• Cylinder Projection

• Sphere Projection

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.

The sculpting tools, Pinch and Relax, will not move any pinned UVs. This allows you to pin the borders, or around interior holes, and gives even more control to the sculpt tools.

Pinning also works great with the Live Unwrap tool. If you pin two or more UVs, with Live Unwrap on, moving or scaling the pinned UVs will interactively unwrap the model. You can even use the Grab sculpting tool to move the pinned UVs. This helps with fitting a UV island to a certain shape or region.

Invert Pins

Reference

Editor:

UV Editor

Mode:

Edit Mode

Menu:

UV ‣ Invert Pins

Pin all un-pinned selected UVs and un-pin all currently selected pinned UVs.

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 can be used to optimize the UV layout by adjusting existing islands to efficiently fill the Texture Space. Based on the options selected, the tool will scale, translate and rotate the islands, ensuring a specified margin exists between them to maximize the usage of the UV space. Pinned islands can have additional restrictions applied to customize the packing process even further.

Shape Method

The method to use when considering the shape of each island.

Exact Shape (Concave):

Use the complete shape of the island, including filling any holes or concave regions around the island.

Boundary Shape (Convex):

Takes into account the boundary (Convex Hull) of the island. This method will not place islands inside holes.

Bounding Box:

Uses the simple bounding box of the island.

Scale

Scale the islands to fill the unit square, or pack islands towards the lower left corner.

Rotate

Allows the rotation of islands, as well as translation and scaling, to optimize texture usage.

Rotation Method

The allowable rotations to use for each each island.

Any:

Any rotation which improves the packing is allowed.

Axis-aligned:

The island will first be rotated into a smallest rectangle. Additional rotation will only be in 90-degree turns.

Cardinal:

Like the four cardinal directions on a compass, North, South, East and West, only 90-degree turns will be allowed.

Margin Method

The method to use when calculating the empty space between islands.

Scaled:

Use scale of existing UVs to multiply margin.

Add:

Simple method, just add the margin.

Fraction:

Precisely specify the fraction of the UV unit square for margin. (Slower than other two methods.)

Margin

The scale for the empty space between islands.

Lock Pinned Islands

An island which has any of its UVs pinned is considered a Pinned Island. With this option, Pinned Islands will be unable to move. The other islands will pack around them.

Lock Method

Change the way Pinned Islands are packed

Scale:

The scale of the Pinned Islands will not change.

Rotation:

Pinned Islands will not rotate.

Rotation and Scale:

Pinned Islands can translate, but not scale nor rotate.

Merge Overlapping

Before the main packing operation, overlapping islands are detected and temporarily combined. During packing, the relative rotation and position of the merged islands are preserved.

Pack To

Determines the final placement of UV islands after completing the packing operation.

Closest UDIM:

Pack islands to the UDIM grid nearest to the center of the selection.

Active UDIM:

Pack islands to the active UDIM image tile or, if no image is available, the UDIM grid tile where the 2D cursor is located.

Original bounding box:

Find the original bounding box of the selection, packs the islands, and then moves them back inside the original box.

Note

The performance of the Pack Islands operator is heavily affected by the options selected, and sometimes the options can combine in different ways to produce unexpectedly slower results.

The fastest results can be obtained by using the “Bounding Box” shape method and the “Add” margin method.

Although enabling the “Rotate” option slightly impacts performance, it will often enhance efficiency, making it a good choice to always keep enabled.

However the “Fraction” margin method requires significantly more computation to find the exact scale. For certain layouts, it may even take up to 10 times longer to complete then using the simpler “Add” or “Scaled” methods.

Similarly, the “Exact shape” and “Boundary shape” methods are much slower than the simple “Bounding Box” method.

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 the difference between the angles in 3D and the angles in UV space. This operation is similar to the Relax tool with the Geometry Relaxation Method, but uses a different algorithm.

Fill Holes

Just during minimize stretch, internal holes will be filled with temporary polygons to prevent stretching and overlaps of the surrounding UVs.

Blend

The fraction between 0 and 1 of the original UVs to blend in once the stretch is minimized. A blend of 0 is the fully minimized stretch. Blend of 0.5 is halfway between the original UVs and the minimize stretch UVs.

Iterations

More iterations result in smoother UVs, but take longer to process.

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.

Align Rotation

Reference

Editor:

UV Editor

Mode:

Edit Mode

Menu:

UV ‣ Align Rotation

The Align Rotation tool aligns entire islands to either the U or V axis.

The tool has three different methods of operation. The different methods specify the source for the alignment, and also whether to align with both the U and V axes, or just the V axis alone.

When using the Auto method, islands are aligned so that UV edges are aligned to either the U axis or the V axis. This method works best with quads and meshes representing organic subjects.

When using the Edge method, only the selected edges are considered, and the islands will be aligned such that the selected edges are aligned with the V axis. This method works with the selection, so it works best when a particular edge, or edge loop, needs to be aligned in UV coordinates.

When using the Geometry method, the geometry is taken into consideration. Either the X axis, the Y axis, or the Z axis can be used. Suppose the X axis is chosen. Using this method, edges which have a positive extent in the X axis will be rotated in the UV map so that the edge extends upwards in the V axis. This method works best to align multiple islands which share some common geometric property, either in the X, Y or Z axis.

Note that in the Auto method, edges can end up aligned either up or down or left or right depending on the orientation of the island prior to activating the tool. In the Edge method, the alignment of selected edges can be either up or down in the V axis, whatever is closest to the current orientation of the UV island. By comparison, in the Geometry method, the alignment will always be pointing up in the V axis, ignoring any previous orientation.

Copy UVs

Reference

Editor:

UV Editor

Mode:

Edit Mode

Menu:

UV ‣ Copy UVs

For each selected UV island, the Copy UVs tool will copy it’s topology and UV coordinates into a temporary clipboard for later use with the Paste UVs tool.

Note

The Copy UVs tool currently uses an internal clipboard which is not shared between instances of blender.

Paste UVs

Reference

Editor:

UV Editor

Mode:

Edit Mode

Menu:

UV ‣ Paste UVs

For each selected UV island, the Paste UVs tool will attempt to match the topology of an island stored in the internal clipboard. If a match is found, the UVs stored in the clipboard for the original island will be pasted onto the currently selected island.

For example, if a triangle attached to a quad attached to a quad is in the clipboard, then a different triangle <=> quad <=> quad is selected, then the topologies match, and the UVs will be pasted over the current selection.

For best results, you may want to use the Rip tool, or UV > Split > Selection, prior to using Paste UVs.

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.

Note

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.

Round to Pixels

During UV transforms, you can use Round to Pixels to help with matching features in the image or ensure your UVs have precise horizontal, vertical or diagonal alignment.

Note that Round to Pixels is applied after any snapping modes.

Disabled:

UVs will not be rounded.

Corner:

Will force the UVs to round to the corner of the nearest pixel of an image if loaded.

Center:

Will force the UVs to round to the center of the nearest pixel 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.