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UV

8 pages · exported 2026-09-06 · https://meshmorpher.com/docs/studio-and-graph/uv

Studio and Graph

UV

Unwrapping, packing and editing UV layouts.

Studio and Graph › UV

Generate UVs

Builds a UV atlas for the mesh from scratch and packs it into the channel you pick. Two unwrappers are on offer: Patch Builder suits sculpted organic shapes, XAtlas copes better with scans and gene...

Generate UVs node

The Generate UVs node

When to use it

Builds a UV atlas for the mesh from scratch and packs it into the channel you pick. Two unwrappers are on offer: Patch Builder suits sculpted organic shapes, XAtlas copes better with scans and generated meshes that turn up with no UVs at all.

Whatever was in the chosen channel is replaced, seams and all. To change only the layout while keeping the unwrap, use Pack UVs instead.

How to use it

  1. 1

    Connect a mesh

  2. 2

    Pick an algorithm and its parameters

  3. 3

    Click Generate UVs

Pins

Pin Type Description
Mesh Mesh The mesh to unwrap.
Pin Type Description
Mesh Mesh The same mesh with a fresh UV layout in the chosen channel.

Settings

Setting Type Description
Method Choice Which unwrapper does the work.
UV Channel Whole number Which UV channel the new layout goes into. Whatever was in that channel is replaced, so point this at a spare channel if you want to keep the old one.
Setting Type Description
Initial Patch Count Whole number How many patches the surface is broken into before any merging happens. More patches means more, smaller islands in the finished layout.
Min Patch Size Whole number The fewest triangles a patch is allowed to hold. Raise it to stop odd triangles ending up as islands of their own.
Curvature Alignment Number How closely a growing patch sticks to surface that faces the same way. Higher pushes the cuts towards the places the shape already turns a corner.
Merging Threshold Number How much stretch you will accept in exchange for merging two patches into one island. Raise it for fewer, bigger islands and more distortion in them.
Max Angle Deviation Number How far apart two neighbouring patches may face and still be merged, in degrees. Drop it towards 30 to keep seams on the hard corners.
Smoothing Steps Whole number Smooths the surface direction before solving, which settles the island shapes down at the cost of a little more distortion.
Smoothing Alpha Number How much each of those smoothing steps moves things.
Pack Islands True/False Lays the finished islands out inside the 0-1 square. Switch it off and they stay where the solve put them, which usually means overlapping. XAtlas always packs, whatever this says.
Setting Type Description
Max Iterations Whole number How many passes XAtlas spends refining where the cuts go. Higher is tidier and slower.
Setting Type Description
Packing Resolution Whole number The texture size the layout is packed for. It turns the padding below from a pixel count into a real UV distance, so set it to whatever you will bake at.
Island Padding Whole number Blank space left between islands, in pixels of the resolution above. Too little and a bake bleeds across an island edge, or the low mips smear the shoulder into the ear. Patch Builder always leaves at least one pixel even at 0; XAtlas will pack flush.
Rotate Islands To Pack True/False Lets islands turn so they nest tighter. Switch it off to keep every island upright, which keeps checker squares square and the layout readable. You give up some coverage for that. Patch Builder only reads it while Pack Islands is on.

Available in Mesh Morpher Graph and Mesh Morpher Studio.

Studio and Graph › UV

Pack UVs

Repacks the UV islands of one channel into the unit square, moving only islands that already exist.

Pack UVs node

The Pack UVs node

When to use it

Repacks the UV islands of one channel into the unit square, moving only islands that already exist.

An atlas generated once is rarely laid out the way the asset finally needs it, and re-running Generate UVs to change the layout throws away the seams and the unwrap along with it. This is the step in between: same islands, same distortion, tighter arrangement.

It needs UVs to work with. On a mesh that has none, Generate UVs comes first.

How to use it

  1. 1

    Connect a mesh that already has UVs

    From Generate UVs, or an imported asset.

  2. 2

    Pick the channel, the resolution you will bake at and a gutter

  3. 3

    Optionally connect Weights to repack only the selected islands

  4. 4

    Click Pack UVs

Pins

Pin Type Description
Mesh Mesh The mesh to repack. It needs UVs in the chosen channel already - this node will not make them.
Weights Weight Map Optional. Repack only the islands this selection touches. Leave it empty to repack everything.
Resolution Whole Number Texture Resolution, taken from the graph instead of the details panel.
Gutter Whole Number Gutter Texels, taken from the graph instead of the details panel.
Pin Type Description
Mesh Mesh The mesh with the chosen channel repacked. The other channels come out untouched.

Settings

Setting Type Description
UV Channel Whole number Which UV channel to repack. The others come out untouched.
Pack Mode Choice How the islands get laid out.
Texture Resolution Whole number The size of the texture you plan to bake at. It turns the gutter below from a pixel count into a real UV distance, and it limits how small an island is allowed to get.
Gutter Texels Whole number Blank space left between islands, counted in pixels of the texture above. Set it too low and a bake bleeds across an island edge, or the low mips smear the shoulder into the ear. 2 to 4 is normal. Go higher when the texture will be seen mostly from a distance.
Allow Rotation True/False Lets islands turn so they nest tighter. Switch it off to keep every island the way you authored it, which keeps checker squares square and the layout readable. You give up some coverage for that.
Allow Flips True/False Lets islands mirror as well as turn. Buys a little more coverage and does no harm on symmetric detail, but any text or directional pattern painted into the texture will read backwards. Ignored while Allow Rotation is off.
Selection Threshold Number A vertex counts as selected once its weight reaches this. Only read when something is plugged into Weights.

Available in Mesh Morpher Graph and Mesh Morpher Studio.

Studio and Graph › UV

Texel Density

Measures, and optionally equalises, texel density across the UV islands of one channel. Texel density is texels per centimetre of surface: Resolution sqrt(UV area / 3D area).

Texel Density node

The Texel Density node

When to use it

Measures, and optionally equalises, texel density across the UV islands of one channel. Texel density is texels per centimetre of surface: Resolution * sqrt(UV area / 3D area).

Auto-unwrappers optimise for packing, not for this, so a generated atlas routinely gives a character's ear four times the texels per centimetre of the torso. That is invisible in the UV view and obvious the moment anything is baked or painted, which is why this is measured in numbers rather than eyeballed.

Normalising scales each island about its own UV centre, so islands can end up overlapping. Follow this node with Pack UVs in Preserve Relative Scale mode, which lays them out again without disturbing the density you just equalised. Fit To Unit Square below is the quick alternative when you only need the result inside the tile and do not care about overlap.

How to use it

  1. 1

    Connect a mesh that already has UVs

  2. 2

    Run in Measure Only and read the Result category

  3. 3

    Switch to a Normalise mode and run again

Pins

Pin Type Description
Mesh Mesh The mesh to measure. It needs UVs in the chosen channel already.
Weights Weight Map Optional. Work on only the islands this selection touches. Leave it empty for the whole mesh.
Resolution Whole Number Texture Resolution, taken from the graph instead of the details panel.
Target Density Number Target Texel Density in texels per centimetre, taken from the graph. Only read in Normalise To Target mode.
Pin Type Description
Mesh Mesh The mesh. Untouched in Measure Only, otherwise with the chosen channel's islands rescaled. The other channels come out untouched either way.

Settings

Setting Type Description
UV Channel Whole number Which UV channel to measure or rescale. The others come out untouched.
Mode Choice Report the numbers only, or rescale the islands as well.
Texture Resolution Whole number The texture size the density numbers are quoted against. Without it they mean nothing: the same UVs read 5 texels/cm at 512 and 20 at 2048. Set it to whatever you will actually bake at. Every density on this node is texels per centimetre in the app's own units.
Target Texel Density Number Texels per centimetre every island gets scaled to. 10.24 works out to 1024 texels per metre, which is where most game work starts. Centimetres means the app's own units, the same ones the viewport measures in. A mesh that was authored in metres and imported without a unit conversion reads a hundred times off, so check the scale before trusting the number.
Fit To Unit Square True/False After rescaling, shrink the whole layout as one piece so it lands back inside the tile. Every island moves by the same factor, so they stay equal to each other, but they are no longer the exact number you asked for. Off by default, since a Target run usually wants that exact number. Ignored while Weights is driving a selection: fitting only the islands you picked would centre that handful in the middle of the tile and park them on top of the ones you left alone.
Selection Threshold Number A vertex counts as selected once its weight reaches this. Only read when something is plugged into Weights. The selection grows out to whole islands first, because half an island has no density of its own.

Available in Mesh Morpher Graph and Mesh Morpher Studio.

Studio and Graph › UV

Transform UVs

Rotates, scales, offsets and flips the UVs of one channel, either across the whole mesh or on the islands a selection touches.

Transform UVs node

The Transform UVs node

When to use it

Rotates, scales, offsets and flips the UVs of one channel, either across the whole mesh or on the islands a selection touches.

The small manual correction that every unwrap eventually needs, and the only one of these operations that has no equivalent anywhere else in the graph: turning a strip upright so its texel grid lines up with the texture, nudging an island off a tile border, mirroring a decal, or scaling a channel into a UDIM tile.

The transform is applied in the order flip, scale, rotate about the pivot, then offset - which is the order that makes the numbers in the details panel mean what they say.

How to use it

  1. 1

    Connect a mesh that already has UVs

  2. 2

    Optionally connect Weights to limit the change to the selected islands

  3. 3

    Set rotation / scale / offset and click Apply

Pins

Pin Type Description
Mesh Mesh The mesh to transform. It needs UVs in the chosen channel already.
Weights Weight Map Optional. Move only the islands this selection touches. Leave it empty to move the whole channel.
Rotation Number Rotation in degrees, taken from the graph instead of the details panel.
Scale U Number Scale U, taken from the graph instead of the details panel.
Scale V Number Scale V, taken from the graph instead of the details panel.
Offset U Number Offset U, taken from the graph instead of the details panel. 1 moves a whole tile.
Offset V Number Offset V, taken from the graph instead of the details panel. 1 moves a whole tile.
Pin Type Description
Mesh Mesh The mesh with the chosen channel transformed. The other channels come out untouched.

Settings

Setting Type Description
UV Channel Whole number Which UV channel to transform. The others come out untouched.
Pivot Choice What the rotation, scale and flip happen around. Get this wrong and a rotation swings the island across the atlas instead of turning it on the spot.
Custom Pivot U Number U coordinate of the pivot point.
Custom Pivot V Number V coordinate of the pivot point.
Rotation Degrees Number Counter-clockwise rotation about the pivot, in degrees.
Scale U Number Scale along U about the pivot. 1 = unchanged.
Scale V Number Scale along V about the pivot. 1 = unchanged.
Offset U Number Slides the UVs along U, applied last. 1 moves a whole tile.
Offset V Number Slides the UVs along V, applied last. 1 moves a whole tile.
Flip U True/False Mirrors across the pivot's V axis. Anything directional in the texture, lettering above all, will read backwards afterwards.
Flip V True/False Mirrors across the pivot's U axis. Same backwards-texture catch as Flip U.
Selection Threshold Number A vertex counts as selected once its weight reaches this. Only read when something is plugged into Weights.
Affect Whole Islands True/False Grows the selection out to whole UV islands before transforming. Leave it on. An island is one continuous patch of texture, and moving half of it tears the patch open - which nothing in the viewport shows you until you bake. Turn it off only when you actually want to shear a region's UVs.

Available in Mesh Morpher Graph and Mesh Morpher Studio.

Studio and Graph › UV

UV Editor

The interactive 2D UV view. See one channel's islands in the tile grid, select them by click or marquee, and move, rotate and scale them by hand.

UV Editor node

The UV Editor node

When to use it

The interactive 2D UV view. See one channel's islands in the tile grid, select them by click or marquee, and move, rotate and scale them by hand.

Pins

Pin Type Description
Mesh Mesh The mesh to edit. It needs UVs in the chosen channel already - this node will not make them.
Pin Type Description
Mesh Mesh The mesh with your edits to the chosen channel. The other channels come out untouched.

Settings

Setting Type Description
UV Channel Whole number Which UV channel is shown and edited. The others come out untouched. A channel that is missing or empty is refused rather than created - run Generate UVs first.

Available in Mesh Morpher Graph and Mesh Morpher Studio.

Studio and Graph › UV

UV Seams

Edits UV seams - where the atlas is allowed to be cut - and re-solves only the islands that changed.

UV Seams node

The UV Seams node

When to use it

Edits UV seams - where the atlas is allowed to be cut - and re-solves only the islands that changed.

Generate UVs decides both the seams and the unwrap in one shot, and the only way to disagree with it today is to run it again with different settings and lose the whole layout. This node is the local alternative: cut or weld a seam where the result is wrong, re-unwrap the handful of islands that were touched, and leave every other island exactly where it is (see Preserve Island Bounds).

How to use it

  1. 1

    Connect a mesh that already has UVs

  2. 2

    Pick a mode; the selection modes need Weights connected

  3. 3

    Leave Re-unwrap on Conformal unless you have a reason not to

  4. 4

    Click Apply, then Pack UVs if the layout needs re-laying-out

Pins

Pin Type Description
Mesh Mesh The mesh to edit. It needs UVs in the chosen channel already.
Weights Weight Map The region to work on. The two selection modes will not run without it.
Angle Number Angle Threshold in degrees, taken from the graph. Only read in Add Seams By Angle mode.
Pin Type Description
Mesh Mesh The mesh with the chosen channel's seams edited and the affected islands unwrapped again. The other channels come out untouched.

Settings

Setting Type Description
UV Channel Whole number Which UV channel to edit. The others come out untouched.
Seam Mode Choice Cut new seams, carve a selection into its own island, or weld seams shut.
Angle Threshold Number How sharply the two faces of an edge have to meet before it becomes a seam. 60 catches hard corners. 30 also catches soft creases, and leaves you with a lot more islands to pack.
Unwrap Method Choice How the affected islands get their UVs worked out again after the edit.
Preserve Island Bounds True/False Drops each re-unwrapped island back into the space it already occupied, at its old aspect ratio. This is what keeps the edit local. A fresh unwrap comes back at some arbitrary size and position, so with this off the re-solved islands land on top of the rest of the atlas and you have to repack everything. Turn it off only when Pack UVs is next in the chain anyway.
Selection Threshold Number A vertex counts as selected once its weight reaches this. The two selection modes need it. In Add Seams By Angle it only limits the search to edges inside the selection, and searches the whole mesh when nothing is wired.

Available in Mesh Morpher Graph and Mesh Morpher Studio.

Studio and Graph › UV

View UVs

Renders a mesh's UV layout into a texture so you can actually look at it. Coloured islands, a texel-density heatmap or wireframe, with seam emphasis, overlap highlighting and UDIM tiles.

View UVs node

The View UVs node

When to use it

Renders a mesh's UV layout into a texture so you can actually look at it. Coloured islands, a texel-density heatmap or wireframe, with seam emphasis, overlap highlighting and UDIM tiles.

Pins

Pin Type Description
Mesh Mesh The mesh whose UV layout you want to look at.
Pin Type Description
Mesh Mesh The input mesh, unchanged.
Texture Asset The layout picture for the tile currently on show.

Settings

Setting Type Description
Resolution Whole number How big the picture comes out, in pixels. It is square, and you get one per UDIM tile.
UV Channel Whole number Which UV channel gets drawn.
Mode Choice What the picture shows: the islands, how evenly the texture is spread, or just the edges.
Island Coloring Choice A colour per island, or one colour for the lot.
Island Color Colour The colour every island is filled with when Island Coloring is on Single Color.
Background Choice What sits behind the layout.
Anti-Aliasing (SSAA) Whole number Renders larger and shrinks back down so the edges are not jagged. 2 is usually enough; 4 draws sixteen times the pixels to get there.
Draw Wireframe True/False Draws the triangle edges over the top of the fill.
Line Thickness Number How thick those edges come out, in pixels of the finished picture.
Emphasize Island Borders True/False Draws the island borders, which are the seams, twice as thick and brighter than the edges inside an island.
Draw Grid True/False Draws a faint grid every 0.1 of a tile, plus the border of the 0-1 square, so you can tell how far across the tile something sits.
Highlight Overlaps True/False Paints any pixel covered by more than one triangle bright magenta. Overlapping UVs bake on top of each other, and this is the quickest way to find where.
Distortion Contrast Number How hard the heatmap pushes the colours apart. Raise it to pick out small differences. Lower it when the whole mesh reads as red and blue with no green left in it.
Enable UDIM True/False Draws every tile the UVs reach instead of only the 0-1 square.
Max UDIM Tiles Whole number How many tile columns to look across, starting at 1001. UVs further right than that get folded back into the last column, so raise it if a tile you expect is missing. All ten rows are scanned either way.
Preview Tile Whole number Which UDIM tile to show, counting from the first one that has UVs in it.

Available in Mesh Morpher Graph and Mesh Morpher Studio.