Blender Un-Bender

A Blender add-on that helps you create ANIMATIONS of unfolding 3D meshes into flat patterns using shape keys. Perfect for creating animations of papercraft models, origami designs, sheet-metal folding or any project requiring 3D to 2D unfolding.

Features

• Edge Marking System

  • Precut: Mark edges to be cut before processing
  • Freeze: Lock edge angles in place during unbending
  • Freestyle: Mark edges for cosmetic/visual purposes

• Multiple Unfolding Methods

  • By Path: Unfold each path independently
  • Trunk First: Unfold from origin outward to branches
  • Branches First: Unfold from outer branches inward to trunk

• Cleanup Options

  • Keep all geometry intact
  • Remove edge markings only
  • Remove all faces (leaving wireframe)
  • Remove all fold edges except frozen ones
  • Remove all fold edges

• Animation Control

  • Shape key-based animation
  • Individual path control
  • Global unfolding control

Requirements

• Blender 4.1 or newer
• Windows/Mac/Linux

Installation

1. Download unbender.zip
2. Open Blender
3. Go to Edit > Preferences > Add-ons
4. Click "Install..."
5. Navigate to and select the downloaded unbender.zip file
6. Enable the add-on by checking its checkbox

Usage

1. Access the Tool

   • Open the sidebar in the 3D View (press N)
   • Find the "Unbender" tab

2. Step-by-Step Workflow

   1. Select a single mesh object in the 3D view
   2. Switch to Edit Mode (Tab key)
   3. Mark edges as needed:
      • Use "Precut" for edges you want to separate
      • Use "Freeze" for edges that should maintain their angle
      • Use "Freestyle" for visual line markings
   4. Switch back to Object Mode (Tab key)
   5. Choose your unbending method and post-processing option
   6. Click "Unbend"
   7. A new object will be created with:
      • Shape keys for animation control
      • Custom driver sliders for fine-tuning

3. Edge Marking Tips

   • Precut edges will be split before processing
   • Frozen edges maintain their angles during unbending
   • Freestyle marks are purely visual
   • Note: Freeze takes precedence over Precut if both are set

4. Face Normals

   • If faces appear inside-out, use the "Flip Face" tool
   • Select faces in Edit Mode to flip their normals
   • Flipped faces will fold inward, opposite direction of adjacent faces

5. Cleanup Options (cumulative)

   • None - leaves new object as-is
   • Marks - removes any precut or freeze markings
   • Faces - Removes faces, leaving just edges
   • All but Frozen - Removes interior edges except for frozen edges
   • All - removes all interior edges except for Freestyle marks

Tutorial Videos

• Unbender Tutorial Video - Basic workflow and features overview

Known Issues

• Large models may take longer to process
• Complex geometry might require manual face normal adjustments -- if your object has non-flat n-gon faces, unfolding won't work
• Flipped faces will fold inward, but require a slight non-180 degree starting angle

Contributing

Feel free to submit issues and enhancement requests!

License

GPL-3.0

Credits

Created by Chris Allen

Version History

• 1.0.0: Initial release
  • Basic unfolding functionality
  • Three unfolding methods
  • Edge marking system
  • Cleanup options