Origami Diagrams

convert a FOLD object into origami diagrams.

FOLD

see example.fold inside /tests as a reference.

presently, this program is reading a FOLD file in this way:

{
  "file_spec": 1.1,
  "file_author": "Robby Kraft",
  "file_title": "African Elephant",
  "file_description": "a complex 3D African elephant with color changing tusks",
  "file_classes": ["diagrams"],
  "file_frames": [{
    ...
  }, {
    ...
  }, {
    ...
  }]
}

The top level only contains "file_" entries (no FOLD geometry). file_frames contains the ordered list of steps to be diagrammed.

  "file_frames": [{
    "frame_classes": ["diagrams"],
    "re:diagrams": {
      ...
    },
    ...
  }, {
    "frame_classes": ["diagrams"]
    "re:diagrams": {
      ...
    },
    ...
  }, {

Somewhere we need to allow the ability to include additional information such as a finished crease pattern or folded form to be printed in places like the page header. Presently, these are included in file_frames, requiring the need to differentiate between diagram steps, and non-diagram steps.

1. If a frame is meant to be a step in the diagram it should have some kind of designation, perhaps a frame_classes "diagrams" entry.
2. alternatively inclusion can be implied by the presence of re:diagrams key, where the actual diagramming data lives. though, this gives the key a dual purpose (layout instructions, and inclusion-in-diagram), which could lead to confusion.

FOLD Extensions

all keys not standard to the FOLD format currently use the Rabbit Ear namespace, "re:"

each diagram step (entry in the file_frames) contains the FOLD geometry for the origami (vertices_coords, faces_vertices), as well as instructions to the renderer regarding diagramming. the re:diagrams frame is laid out like this:

"re:diagrams": [{
  "re:diagram_lines": [
    {
      "re:diagram_line_classes": ["valley"],
      "re:diagram_line_coords": [[0.5, 0], [1, 0.5]]
    }
  ],
  "re:diagram_arrows":[
    {
      "re:diagram_arrow_classes": [],
      "re:diagram_arrow_coords": [[1, 0], [0.5, 0.5]]
    }
  ],
  "re:diagram_instructions": {
    "en": "valley fold",
    "es": "doblez de valle",
    "zh": "谷摺"
  },
  "re:diagram_step": "1"
}]

re:diagrams is an array, sometimes diagram steps contain multiple steps inside ("reverse fold the beak, crimp the feet"). also, both arrow and line definitions are arrays making room for multiple arrows or lines per step.

re:diagram_lines

contains an array of lines to represent crease lines, like dashed lines or solid marks. line is defined by two endpoints re:diagram_line_coords, and diagram_arrow_classes are directions to the rendering engine to describe the line style.

re:diagram_arrows

an array containing definitions for arrows. re:diagram_arrow_coords are the two endpoints, ordered start to end. re:diagram_arrow_classes are directions to the rendering engine to describe the arrow style.

re:diagram_instructions

written instructions, typically these are printed under each step. this is an object with each string under a key matching the ISO language codes.

re:diagram_step

making it possible to have steps with custom names: 1, 2, 3a, 3b, 4...

License

MIT