Installation

1. Download seammend-1.0.0.zip. Do not unzip it.
2. In Blender, open Edit → Preferences → Get Extensions.
3. Click the ⌄ menu in the top-right corner and choose Install from Disk…
4. Select the .zip file and click Install from Disk. (You can also drag the .zip into the Blender window.)
5. Make sure SeamMend is ticked in the list.

Updating: install the new .zip the same way. It replaces the old version.

Unwrapping a model

1. In Object Mode, select one or more mesh objects.
2. Press N in the 3D View (or the UV Editor) and open the SeamMend tab. You can also press U in the 3D View and choose SeamMend Auto Unwrap.
3. Pick a mode and click Auto Unwrap.

The status bar reports the number of islands, the average stretch (1.00 means none) and the time taken. Ctrl+Z undoes everything.

Only part of a model: in Edit Mode, select the faces you want and click Auto Unwrap. The other faces keep their UVs, and the border of your selection becomes a seam.

Modes

• Fewer Islands: the biggest islands. Curved parts get short extra cuts, placed in hidden spots, so they can lie flat. Accepts a little more stretch.
• Balanced: the default and the best choice for most models.
• Low Stretch: more islands with almost no stretch. Use it for detailed hand painting and baking.

Options

• Mark Seams Only: marks the seams but leaves your UVs untouched, so you can edit seams first. Then unwrap with U › Unwrap, or press Auto Unwrap with Keep My Seams on.
• Keep My Seams: seams you marked are treated as fixed cuts. SeamMend adds whatever else is needed.
• Cut at Sharp Edges: also cut along edges marked Sharp.
• Upright Islands: turns every island so the object's up axis (local Z) points up in UV space. Packing will not rotate islands when this is on.
• New UV Map: writes the result to a UV map called “SeamMend” instead of overwriting the active one.
• Pack Islands / Rotate / Margin: packing into the 0–1 square. Margin is a fraction of the UV square (0.004 ≈ 4 px on a 1K texture).
• Pack Objects Together: with several objects selected, all islands share one UV square, for objects that use one texture.

Tips

• Apply scale first (Ctrl+A › Scale) so texel density is even between objects.
• Separate loose parts never share an island. Merge by Distance first if your model is split along its seams.
• Very dense meshes work, but they take longer and give more islands. Unwrap a retopologized or decimated version and bake down if you can.
• If one area isn't how you like it, use Mark Seams Only, adjust the seams, and then Auto Unwrap with Keep My Seams on.

Benchmark details

13 test models, unwrapped with Smart UV Project (angle limit 66°), xatlas 0.0.11 (default settings), and the three SeamMend modes. Smart UV Project and SeamMend results packed by Blender 5.0; xatlas used its own packer. “Visible stretch” is the share of surface area where texture squares are stretched more than 1.5× in one direction. “Texel density error” is the average difference in texture resolution across the surface after packing.

Islands (lower is better)

Area with visible stretch, % (lower is better)

Support

Message MendWorks through Superhive. Include your Blender version and, if you can, the model (or a screenshot of the result). I reply within 72 hours.