Origami Simulator

Телеграм -> @oscave

ORIGAMI SIMULATOR

This app allows you to simulate how any origami crease pattern will fold. It may look a little different from what you typically think of as "origami" - rather than folding paper in a set of sequential steps, this simulation attempts to fold every crease simultaneously. It does this by iteratively solving for small displacements in the geometry of an initially flat sheet due to forces exerted by creases. You can read more about it in our paper:

Fast, Interactive Origami Simulation using GPU Computation by Amanda Ghassaei, Erik Demaine, and Neil Gershenfeld (7OSME)

All simulation methods were written from scratch and are executed in parallel in several GPU fragment shaders for fast performance. The solver extends work from the following sources:

Origami Folding: A Structural Engineering Approach by Mark Schenk and Simon D. Guest
Freeform Variations of Origami by Tomohiro Tachi

This app also uses the methods described in Simple Simulation of Curved Folds Based on Ruling-aware Triangulation to import curved crease patterns and pre-process them in a way that realistically simulates the bending between the creases.

Originally built by Amanda Ghassaei as a final project for Geometric Folding Algorithms. Other contributors include Sasaki Kosuke, Erik Demaine, and others. Code available on Github. If you have interesting crease patterns that would make good demo files, please send them to me (Amanda) so I can add them to the Examples menu. My email address is on my website. Thanks!

Instructions:

Slide the Fold Percent slider to control the degree of folding of the pattern (100% is fully folded, 0% is unfolded, and -100% is fully folded with the opposite mountain/valley assignments).
Drag to rotate the model, scroll to zoom.
Import other patterns under the Examples menu.
Upload your own crease patterns in SVG or FOLD formats, following these instructions.
Export FOLD files or 3D models ( STL or OBJ ) of the folded state of your design ( File > Save Simulation as... ).

Visualize the internal strain of the origami as it folds using the Strain Visualization in the left menu of the Advanced Options.

If you are working from a computer connected to a VR headset and hand controllers, follow these instructions to use this app in an interactive virtual reality mode. (sorry I think this may be deprecated now!)

External Libraries:

All rendering and 3D interaction done with three.js
svgpath and path-data-polyfill helps with SVG path parsing
FOLD is used as the internal data structure, methods from the FOLD API used for SVG parsing
Arbitrary polygonal faces of imported geometry are triangulated using the Earcut Library and cdt2d
numeric.js for linear algebra operations
GIF and WebM video export uses CCapture

You can find additional information in our 7OSME paper and project website. If you have feedback about features you want to see in this app, please see this thread.

Feedback

Fold Percent :

Show Advanced Options

Hide Advanced Options
Fold Percent : %

Allow User Interaction

Start Simulation

Pause Simulation

Reset

Simulation Settings:

Numerical Integration: Euler (first order) Verlet (second order)
Axial Stiffness : Face Stiffness : Fold Stiffness : Facet Crease Stiffness : Damping Ratio :

Animation Settings:

Δt = seconds
Num simulation steps per frame:

Step Forward

Re-center geometry

Error:

Average vertex error:
Load more origami patterns here! Help Us Improve Origami Simulator ➜

Material

Strain View Mode

Flat

Folded Fold Percent: %

Rotate

Grab Control Mode

Reset

View Settings:

Mesh Material: Mesh Visible Colored Material Color 1 (rgb hex):
Color 2 (rgb hex):
Strain Visualization

Max Strain: %
Face Normals Material

Edge Visibility: Edges Visible Mountains Valleys Facet Creases Undriven Edges Boundary Edges

Virtual Reality:

Status:

DESIGN TIPS
Bad design files will throw errors and create models that explode or cannot be solved, here are some tips for importing FOLD or SVG files that work.
Importing FOLD:
The FOLD file format is specified in these docs. This tool imports FOLD v1.0 files with all of the following fields populated:

vertices_coords
edges_vertices
edges_assignment
faces_vertices

You may specify the target fold angle of each crease using the edges_foldAngle field. Note that fold angle is a number in degrees lying in the range [−180, 180]. The fold angle is positive for valley folds, negative for mountain folds, and zero for flat regions. Accordingly, the sign of edges_foldAngle should match edges_assignment if both are specified. You may also assign a null fold angle to a crease so that it is allowed to move freely - this is especially useful when the fold angle is unknown or the crease pattern is fully constrained and able to be driven by other creases in the system.
If you are unsure whether your FOLD file is valid, you can inspect it using the

FOLD Viewer. If you are having trouble, please refer to the

FOLD spec.

Importing SVG:

The SVG importer supports path, line, rect, polygon, and polyline objects with the appropriate stroke color:
Mountain folds have red stroke - rgb(255, 0, 0), hex #ff0000
Valley folds have blue stroke - rgb(0, 0, 255), hex #0000ff
Boundary edges have black stroke - rgb(0, 0, 0), hex #000000 - use this edge type for both the outline of the pattern, and any internal holes.