Step-by-step guide
Skadira
Straighten a selected Blender quad UV strip. Select one continuous strip of quad faces and straighten its UVs into a rectangular grid while leaving the mesh geometry in place.
You have one open strip of quad faces (a road, belt, ribbon, trim or pipe section) whose UV island is curved or uneven, and you want its UVs laid out as a straight, evenly spaced rectangle without changing the mesh.
The guide and practice files are free to read and download. The complete program is in the paid download; the free practice pack does not include it.
See it in use
Straighten a curved ribbon’s UV strip
A screenshot walkthrough with fictional practice data. Select a step to explore.
1. Start with
Straighten a curved ribbon’s UV strip
The practice Blender file has a four-quad ribbon bent through 90 degrees.
Sample files and contents
examples/skadira/curved-ribbon.blend: a fictional ribbon of 4 quads bent through 90 degrees, whose UVs follow the curve. All four faces are already selected.
Practice files and guides are free. The complete app is included only where the product page says so.
2. In the app
Try it in three steps
- Open a copy and select Curved ribbon in Edit Mode.
- Validate the selection and review its four quads.
- Straighten the UV strip and inspect the UV Editor.
Show every click and setting
- Install Skadira as above. Open a copy of examples/skadira/curved-ribbon.blend; if Blender restores a Preferences editor, switch to a 3D Viewport or the UV Editing workspace.
- Click the object Curved ribbon, press Tab for Edit Mode and open the sidebar's Skadira tab with N.
- Click Validate Selection.
- Click Straighten Strip, then look at the UVs in the UV Editor (for example in the UV Editing workspace).
3. The result
Inspect the result
The synthetic host capture shows a straightened UV layout while mesh geometry stays unchanged. Other materials and physical outputs are untested.
What to check in the practice result
Validate reports a valid strip: 4 quads, 5 cross-sections, uniform spacing, rectangle 0.7023 x 0.1000 UV, and nothing changes. Straighten Strip turns the curved UV arc into a straight rectangle of the same size with five evenly spaced cross-sections, inside the 0 to 1 UV square. The mesh does not move. Ctrl+Z brings the curve back. This is the expected practice result. This release verified opening the file and its four selected quads in Blender 4.5.14 Linux; it did not capture manual GUI straighten/Undo on that file. The separate synthetic host captures below illustrate the operation.
This fictional example is shown in the working interface and in the supplied result. Review the guide before using your own files.
See the workflow at a glance
Choose a short explanation, then follow the worked example below. Check the requirements and compatibility before using your own files.
Straighten the UV ribbon. Keep the mesh in place.
A curved ribbon does not always need curved UVs. Skadira straightens one selected, open, unbranched quad strip into a rectangular UV grid while leaving mesh geometry in place. Watch the four-quad curved-ribbon example: validate the strip, straighten its UVs and undo the result. The host GUI was checked in Blender 4.5.14 on Linux. This is a narrow tool for a continuous strip, not general unwrapping, packing, branching or mesh repair; Windows and macOS remain unverified.
55-second silent illustrated overview. Reference images and educational illustrations explain the documented workflow; this is not a new recording of it.
Read the complete video transcript · Download MP4
View the illustrated card
Before you start
- Blender 4.5 LTS; verified host is 4.5.14 on Linux. Other patches, macOS and Windows remain unverified.
- A mesh with a UV map. You select one continuous, unbranched strip of quads in Edit Mode.
- Checked on Linux with Blender 4.5.14. Windows and macOS have not been checked yet.
- The skadira-0.1.2-guide-bundle.zip download contains the unchanged program/skadira-0.1.0.zip.
Your first result
Download and extract your bundle
Buy the Skadira bundle at /store/skadira/ and extract skadira-0.1.2-guide-bundle.zip. Keep program/skadira-0.1.0.zip zipped: Blender installs that inner ZIP. Open GUIDE.html for this manual and PRACTICE.txt for the worked exercise.
Install it in Blender
In Blender 4.5.14 open Edit > Preferences > Get Extensions. Use the top-right menu > Install from Disk and select program/skadira-0.1.0.zip. Leave Enable on Install checked, then confirm Skadira UV Strip Straighten is enabled in Preferences > Add-ons. The unchanged inner README describes the older Add-ons installation route; use Get Extensions on this tested host.
Select one strip
Click one mesh object, press Tab for Edit Mode and switch to face select (press 3). Select one continuous strip of quads: no triangles, no branches, not a closed ring. Only one object may be in Edit Mode.
Open the Skadira tab
In the 3D Viewport or the UV Editor press N to open the sidebar and click the Skadira tab. The Straighten UV Strip panel shows what it needs next (for example “Select one quad strip”) and how many faces are selected. The same two commands are also at the end of the UV menu (U in Edit Mode) as Validate UV Strip and Straighten UV Strip.
Validate first
Click Validate Selection. It only checks the strip and changes nothing. On success the panel says “Strip is valid”; a refusal names the next step, for example “Deselect tris and ngons” or “Deselect one face to open it”.
Adjust options if needed
Shape: Spacing (Uniform or Edge Length), Strip Axis (Auto, U or V) and Size (Keep UV Scale or Unit). Input: Selection (Auto, Mesh or UV) and Pinned UVs (Cancel or Move). The defaults suit most strips; Edge Length keeps long quads long, Unit makes the longer side exactly 1.0.
Straighten
Click Straighten Strip. The strip's UVs become an axis-aligned rectangle; other islands, other UV maps, pin flags and the mesh itself stay as they were. The panel says “Strip straightened”. The Straighten UV Strip redo panel at the bottom left lets you change Spacing or Strip Axis without selecting again.
Undo or save
Ctrl+Z undoes the whole straighten in one step. Nothing is saved automatically: to keep the new UVs, save your .blend file (File › Save). The panel settings are stored in that .blend file too; the add-on writes nothing else to disk and uses no network.
A worked example
Straighten a curved ribbon
Input: examples/skadira/curved-ribbon.blend: a fictional ribbon of 4 quads bent through 90 degrees, whose UVs follow the curve. All four faces are already selected.
- Install Skadira as above. Open a copy of examples/skadira/curved-ribbon.blend; if Blender restores a Preferences editor, switch to a 3D Viewport or the UV Editing workspace.
- Click the object Curved ribbon, press Tab for Edit Mode and open the sidebar's Skadira tab with N.
- Click Validate Selection.
- Click Straighten Strip, then look at the UVs in the UV Editor (for example in the UV Editing workspace).
Expected result: Validate reports a valid strip: 4 quads, 5 cross-sections, uniform spacing, rectangle 0.7023 x 0.1000 UV, and nothing changes. Straighten Strip turns the curved UV arc into a straight rectangle of the same size with five evenly spaced cross-sections, inside the 0 to 1 UV square. The mesh does not move. Ctrl+Z brings the curve back. This is the expected practice result. This release verified opening the file and its four selected quads in Blender 4.5.14 Linux; it did not capture manual GUI straighten/Undo on that file. The separate synthetic host captures below illustrate the operation.
More application screens
Install, validate, straighten and undo
Actual Blender 4.5.14 Linux captures. Installation was checked for this guide update; the three strip states are separate captures from the earlier synthetic host check.
1. Install the inner ZIP
2. Confirm the extension is enabled
3. Validate one selected strip
4. Inspect the straightened UVs
5. Return to the previous UVs
Troubleshooting
The buttons are greyed out or the Skadira tab is missing.
The commands work only in Edit Mode on one mesh object; the tooltip then says “Enter Edit Mode on a mesh object first”. Also check that Skadira UV Strip Straighten is ticked in Preferences › Add-ons and that you are running Blender 4.5.x.
The strip is refused, for example CLOSED_LOOP, BRANCHING_STRIP, NON_QUAD_FACE or DISCONNECTED_SELECTION.
Nothing was changed. Select one open, connected strip of quads: deselect one face to open a ring, remove side branches, and deselect triangles and ngons. The panel's second line names the next step.
The panel says “Pinned UVs block run” and “Unpin or set Move”.
The strip contains pinned UVs and Pinned UVs is set to Cancel. Unpin them, or set Pinned UVs to Move: pinned UVs then move but keep their pin flag.
The result says “Straightened with warning” and “Outside unit square”.
With Size set to Keep UV Scale, a strip that is longer than one UV unit extends past the 0 to 1 square. Set Size to Unit to make the longer side exactly 1.0, or move and scale the island yourself.
The panel asks you to “Select full UV faces”.
With UV sync selection off, Selection: Auto reads the UV Editor's selection. Select the same faces in the UV Editor, or set Selection to Mesh.
INCONSISTENT_WINDING or “Recalculate normals”.
Neighbouring quads face opposite ways. Use Mesh › Normals › Recalculate Outside, then validate again.
Compatibility & limits
- One open strip of quads on one object at a time. It is not a general unwrap, packing, UDIM or mesh-repair tool.
- Blender 4.5 LTS only; checked on Linux with 4.5.14. Windows, macOS and other 4.5 patch versions are not checked yet. Work on a copy of important scenes.
- No automatic updates: to update, install a newer ZIP from the Skadira page the same way.
- Free software under GPL-3.0-or-later: you may use, study, share and change it under that licence. The full text is inside the ZIP (LICENSE and COPYING.md).
- One continuous open quad strip only. No general unwrap, packing, UDIM, branching, multi-object editing or mesh repair. Host GUI checked on Blender 4.5.14 Linux; macOS and Windows unverified.
- Guide bundle 0.1.2 corrects instructions only. Inner program 0.1.0 is byte-identical. Full-v1 macOS two-patch acceptance, artist review of at least 20 strips and timing/checker comparison with native tools and UV Squares remain open.
Need a hand?
Tell us the product, host application and version, what you tried, and the exact error. Contact support with a fictional example; keep private customer files and passwords out of your message.