Pack UVs
Pack UVs takes a mesh that already has UVs and lays its islands out again inside the texture. Every island keeps its shape and its seams; only where it sits changes. Use it on an imported model whose islands overlap or fall outside the texture, or to tidy a layout that wastes space. Unlike Smart UV and Auto Unwrap, it never re-unwraps the mesh.
What it changes
Section titled “What it changes”An island is a group of faces whose UVs are joined. Pack UVs finds the islands from the UVs themselves, so the seams the model was made with stay exactly where they were. Islands that share texture space, such as the two mirrored halves of a character or a stack of copies, are separate islands and come out side by side.
All islands are scaled by the same amount, so a part that had twice the texture detail of another still has twice as much. The islands are fitted together by their real outlines, the same way Auto Unwrap packs its charts: the largest go in first and small ones drop into the gaps beside them. The whole layout then grows as large as the texture allows.
Nothing else about the mesh changes: its points, faces, shading, material slots and named selections all come out as they went in. An imported model’s parts export as edited, because their UVs differ from the file’s.
Island margin and Rotate
Section titled “Island margin and Rotate”Island margin is the smallest gap between two islands, as a share of the texture’s width. The default, 0.004, is about 8 pixels on a 2048 texture. Islands also keep half a margin from the texture’s edge. If the margin is too wide to fit every island, Pack UVs packs them with a narrower one and shows a warning.
Rotate lets each island turn to fit better: first to the angle where its bounding box is smallest, then by any quarter turn. Islands are never mirrored. Turn it off when the direction of a texture matters, for example wood grain or lettering, and each island keeps the way it faced.
Textures after packing
Section titled “Textures after packing”The islands move, so a texture painted on the old layout no longer lines up, and Pack UVs shows a warning when the mesh carries one. To keep the look, add a Bake after it: wire the packed mesh as the target and the mesh from before Pack UVs as the source. Bake copies the textures onto the new layout. A texture that reads a second UV set is not affected.
A mesh with no UVs stops with an error. Give it UVs first with Smart UV or Auto Unwrap.
Inputs
Section titled “Inputs”A mesh that already has UVs.
Outputs
Section titled “Outputs”The same mesh with its UV islands laid out again inside the 0 to 1 UV square, none overlapping.
Parameters
Section titled “Parameters”| Parameter | What it does | Default |
|---|---|---|
Island margin | The gap left between islands, as a share of the texture’s width, so a color painted on one does not bleed onto its neighbor. 0.004 is about 8 pixels on a 2048 texture. | 0.004 |
Rotate | Lets islands turn to fit the texture better. Off, every island keeps the way it faced. | On |
See also
Section titled “See also”- Bake: copy textures onto the packed layout.
- Clean & Repack: a template that repairs an imported model, packs its UVs and bakes its textures across.
- Auto Unwrap: new UVs for an organic or mixed shape.
- Smart UV: new UVs for a hard-surface shape.
- Texture nodes: the other nodes that unwrap, paint and bake.