Origami Fold Blender Add-on

This is a simple add-on for Blender 2.90+ that adds some commands to the mesh 'edge' sub-menu for creating armatures that simulate paper folding around an edge.

Presently you can create armatures that:

• Fold the "left" side of the edge
• Fold the "right" side of the edge
• Fold both sides simultaneously (like 'mountain' or 'valley' folds)
  • Just a pre-linked left & right fold

Other features available:

• Link any new fold to the one previously created so they fold at the same time
• Create new folds as parents of previously created folds
  • Left parents to left, right parents to right

Possible future features:

• Bevel edge to give fold some thickness
• More than 1 axis of symmetry (e.g. more than left vs right)
• Think about IK for squash and inside-reverse folds
• Support for other advanced 3d fold types

Installation

• Click 'code -> download zip' above to download the add-on zip
• Extract the one folder inside, rename it to 'OrigamiFold', then re-zip it
  • Note: I will eventually post releases that avoid this step
• In Blender, open the preferences pane
• Click 'Add-ons' at the left then 'Install..' near the top
• Select the Origamifold.zip file you created
• Locate 'Mesh: Origami fold' in the list and enable it

How it Works

The concept behind this add-on was largely inspired by the following Youtube Video:

• How to make animation of paper plane in Blender

I automate placement of bones and avoid multiple armatures by:

• Using vector math to compute orientations that are perpendicular to the edge
• Painting weights automatically using an internal plane equation with the edge and the paper's surface normal
  • Some vertex weighting is not needed due to parented bones
• If a bone moves an edge containing another bone, it becomes that bone's parent
  • This avoids needing multiple armatures

Basic Workflow (for very simple models like paper planes)

Here's a basic workflow to create an animation similar to the one above:

Prepare your paper:

• Create a plane/quad aligned with XY-plane of the proper dimensions.
• Cut edges into the plane with the knife or subdivision tool to match the crease pattern of your target model.
• Ensure there is only one vertex at each edge endpoint (merge duplicates)

Create your folds:

• Select all edges segments (along a single fold)
• In the 'edge' menu (View3D, edit mode) select Origami Fold
• Add the fold type desired

Tips:

• Think about dependencies as you create your folds
  • If two folds are a mirror image, consider using the 'linked' feature
  • If fold will move the bone of one coming later, make the LATER one first and then use the 'parent' feature
• The order you create folds matters when using the 'linked' and 'parent' features

Examples

(coming soon)