Change the target angle
See this course’s project requirements
An original accordion fold study with three SVG variants, checked geometry, target-angle comparisons and an honest simulation or paper-model record.
Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.
What to include
- An original four-panel pattern with M/V assignments and checked dimensions.
- A three-state partial-fold log or labeled paper-state sketches.
- A comparison of 90-degree and 45-degree targets.
- A width revision from 120 to 160 coordinate units.
- Original input files, comparison notes and simulation exports or paper-model descriptions.
Review and revise
Use these criteria to check your work and choose what to improve.
- Crease assignments and panel geometry match the specifications.
- Target-angle calculations are correct.
- Controlled comparisons identify what changed.
- The method and limits are stated accurately.
Want more background?
The idea in everyday life
Pattern C keeps A’s 120×60 boundary and crease positions 30, 60, 90, but changes crease opacity from 0.5 to 0.25. The documented mapping is opacity×180 degrees.
In this SVG importer, crease opacity encodes target angle; it is a numeric instruction as well as a visual property.
Change the target angle — guided practice
Compare the same crease geometry with a shallower target.
Pattern C keeps A’s 120×60 boundary and crease positions 30, 60, 90, but changes crease opacity from 0.5 to 0.25. The documented mapping is opacity×180 degrees.
1. Predict before importing
Write A: 0.5×180=90 degrees and C: 0.25×180=45 degrees. Note that panel geometry and mountain/valley assignments stay the same.
You should see: The controlled change halves the target bend.
A prediction states what the comparison is intended to test.
2. Create and load C
In accordion-fixture.html choose C and Download SVG. Import accordion-C.svg using the same straight-line settings. Inspect Pattern view and set Fold Percent 100.
You should see: C has the same four panels with shallower requested folds.
Keeping the boundary fixed isolates the target-angle change.
3. Compare equal requested angles
Compare C at 100% with A at 50%. Both request 45-degree changes from flat. Use Reset before each run and similar viewpoints; record whether their settled appearances are similar.
You should see: The two parameter combinations request the same bend amount.
Different controls can combine to produce an equivalent target.
4. Document what remains approximate
If the two screenshots differ, record solver settling or viewpoint as possibilities rather than inventing a material explanation. Paper route: make one shallower and one deeper pleat state; compare qualitatively. Save your comparison note.
You should see: The note includes both the equivalent-angle calculation and actual observation.
Numerical equivalence of targets does not prove identical screenshots or physical behavior.
What to finish
A target-angle comparison with a checked equivalence calculation.
Watch for this
Assuming opacity is only cosmetic in this importer.
How can I tell I understand it?
Explain the result, reproduce the procedure, and complete the changed-input check.
Quick knowledge check
Answer all 3 questions. Get at least 2 right and the lesson completes automatically.
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Pass the check. We’ll save the progress.
Answer all 3 questions above and get at least 2 right. You can review the explanations and try again.
Go to the knowledge checkOptional course overview video · same video as Lesson 1
Class 1: Overview for MIT 6.849 Geometric Folding Algorithms: Linkages, Origami, Polyhedra
From MIT OpenCourseWare. Watch here or open it on YouTube .
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Sources and further reading
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Source & access notes · checked 2026-09-12
Read Fold Percent, SVG stroke/opacity rules, import, pattern view, strain explanation and export controls. WebGL simulation was not operated.
Access: Public reading without a paid account; reviewed September 12, 2026.
Reuse: Link only. Lessons and practice assets are original; free access does not grant permission to copy the provider's material.
Source & access notes · checked 2026-09-12
Read original project description, simultaneous-fold solver, constraints, SVG/FOLD input and GPU method.
Access: Public reading without a paid account; reviewed September 12, 2026.
Reuse: Link only. Lessons and practice assets are original; free access does not grant permission to copy the provider's material.
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